PREREQUISITES - to begin with, it is assumed you know how to hook-up and operate a VCR. You should also be familiar with the parts in the VCR Mechanical Components section. No other repair experience is required.
These 15 problems are the most common defects that repair shops see from VCRs made in the 80's. You could say they are also somewhat common to all VCRs. In event your problem does not show up in our database, there is a good chance it may be one of these. Out of all the hundreds of things in a VCR that could fail, it usually turns out to be one of these 15. You could have one of these problems and not even know it.
Many of the following are just too common to be placed in the Database Pages. For example, a reel belt on a capstan reel drive mechanism (found in over 90% of all VCRs) will develop the same symptoms in nearly all of them. It would be redundant for us to post this problem for all of them.
A good place to start if the Database Page doesn't help you, look this page over if your VCR was made in the 80's or the Top 10 Defects of the 90's and see if you are experiencing some of these symptoms. If so, there is a high likelyhood that may be it.
As a good educational approach, it's a good idea to familiarize yourself with these defects and identify where these parts are located in your VCR. That is what professionals do. They make an effort to become very familiar with common defects and don't waste much time on things that rarely fail. When there is a problem, common sense should tell you, it's much more likely (not always) to be something common.
1. DIRTY HEADS - symptoms:
With these symptoms, it's most likely your video heads are clogged. This happens most frequently when you rent movies. A certain number of previous renters have defective VCRs that can put substancial contaminents on the tape. You rent that movie and guess what? Your heads are now gunked up.
THE CURE - clean the heads. There are several ways this can be done. Believe it or not, the easiest, is to play an ordinary tape in the VCR for an hour. No, you won't be able to see the picture, so do something else to keep yourself occupied while it plays. Over a period of time the tape removes particles from the heads and restores your picture to normal. The scrubbing action of the video head spinning at 1800 RPM is what makes this possible. Surprisingly, this works about 2/3rds the time. You might also want to try one of the special Head Cleaning Cassettes. In event all else fails, you will have to open it up and physically clean the heads with swabs and cleaning fluid. If done incorrectly, this can ruin the upper drum assembly so be sure to read the section on VCR CLEANING before proceeding.
2. IDLER - symptoms:
THE PROBLEM - worn idler. Older VCRs have an idler that uses a rubber tire. Over the years, a slow chemical reaction occurs on the surface of the tire. This process results in a glazed surface, causing loss of traction. With a dummie cartridge you can see that the idler does engage the reel table, but if you grab the reel table with your hand, you find there is little or no torque. Without traction, the tire only slips against the reel table. If you push the idler into the reel table with your finger, it will work, but only as long as you keep your finger on it. Often all you need to do is replace the tire.
The tire can be easily removed. It's not glued or permanently fastened in any way. A small flatblade screw driver is a big help in removing the old one. In fact, you can turn it inside out and remount it that way. But since there are no treads on the inside wall and the fact the rubber has a lot of years of deterioration on it, you will be lucky to get a few months out of it. But at least you can still use your VCR in the meantime.
Newer VCRs have a gear instead of a tire. Although gears are much more reliable they still have problems. Usually becoming warped or loosing tension. The plastic retaining cap over the spring sometimes cracks. Without sufficient tension, the idler tends to get caught between the reels. This can be easily seen if you have a dummie cartridge. Gear driven idlers are one piece, so replacement involves the entire idler.
3. BELTS - symptoms:
4. CPU RESET - do you know where the reset button is on your VCR? If you say there is no such thing, we have a surprise for you. No, it's not a red button on the back, but you can still operate it without even openning your VCR. Simply by removing the AC power plug for about 30 seconds and then plugging it back in again. This resets the CPU. Turning the VCR off with the power button won't work; it must be unplugged.
This can solve a number of problems. Any time your VCR appears to be dead or doesn't respond to anything, try resetting it. Any time it behaves weird, like your channel indicator locks up or your clock goes to all 8's, try resetting it. This phenomenon occurs a lot more often than most people think. The primary cause is believed to be static electricity and power surges. You know that feeling you get when you walk across a staticy carpet and touch something like a door knob. It seems like it shocks your finger tip off. This electricity can also rearrange the digits inside your VCRs CPU. Fortunately, resetting fixes most of these problems.
5. CAPSTAN BEARINGS - symptoms:
The easiest way to positively identify a bad bearing is to put one small drop of oil on it and see if the symptoms vanish. It's easy to get to from the top. The capstan shaft comes up through it. Sometimes there is an oil seal on top of it. You can usually pry it up slightly and to get the oil underneath it. Remember, just a drop! Be sure no oil goes up the shaft. That is not good for the pinch roller or the tape. It might be a good idea to wipe the shaft good with a lint free paper towel or rag. The oil may even fix it for a few months, but eventually the bearing will need to be replaced.
6. ROLLER GUIDES - symptoms: Horizontal lines in picture. Tracking control won't cure it.
7. ANTENNA BLOCK - symptom: coax connector falls off. This can happen if someone yanks on the coax cable a little too hard. Also some VCRs are manufactured so cheaply these days that it is possible they can fall off all by themselves over time. Unfortunately, you just can not glue these back on again. These are attached to a metal box inside the VCR. Inside the box is a circuit board usually consisting of the modulator circuits. When these connectors come off they must be reattached from inside the metal modulator box. It can be done, however, but it requires good soldering skills and can be very time consumming. It is usually much easier to replace the entire modulator itself. Sometimes it's refered to as the Modulator Block.
8. FOREIGN OBJECTS CAUGHT IN MECHANISMS - these objects come from two different sources. Those that get in there by accident, like labels comming off cassettes; and things that get in there by small kids, things like toys, rocks, crayons and food. When one kid was asked why he put a sandwich inside the VCR, his answer was he did not want the cat to get it. Top loaders are more prone to strange objects because whatever is on top has a chance of accidently falling in. Usually these objects cause mechanism jams that trip your VCRs shutdown mechanisms. Anything caught in the roller guide slides will not allow the guides to load up correctly, causing a poor jumpy picture with noisy lines in it. With the cover off, a careful examination of the mechanical mechanisms will usually reveal any foreign objects that do not belong inside. Simply removing them is usually all that is necessary to comeplete the repair.
9. RELAYS - often found on older VCRs, relays are notorious for causing trouble. They were commonly used in head switching and audio circuits. The problems are mostly with the relay contacts. Over the years, the surfaces of the contacts degrade until they reach a point where they can no longer complete a circuit. Head switching relays were standard in older four head VCRs. The position of the relay determines which pair of heads to use. A typical symptom of a bad head switch relay is a good picture at one speed, but distorted on another. What happens is that when the relay is in one position, it is makeing good contact for both heads. But in the other, only one head is getting a good connection. You can usually confirm a bad relay by pressing on it to see if it momentarily corrects the problem. Audio relays were used mostly in portable VCRs and are the first thing you suspect when there is no sound or does not record sound. Some soldering is required to complete this repair.
10. TAPE END SENSORS - all VCRs have two of them. One for supply and one for takeup. They have this name because their job is to sense the end of the tape. Operation is based on a beam of light that comes from the center of the cassette, goes through it, and hits the End Sensor. Depending on whether the beam hits tape or clear tape leader, determines if the sensor is tripped or not. For this discussion it may be helpful to have a VHS cassette in front of you to observe.
The large round hole you see in the center of the bottom side is for an infra red lamp to poke up into it when the cassette loads into position inside the VCR. It shoots a beam of infra red light through the cassette in two different directions, exiting through a small hole on opposite ends. These holes can be seen if you if you open the cassette lid (you will have to release the catch on the right end). From there, the light travels on to the End Sensors on the carriage side plates.
Inside the cassette, notice the clear leader that attaches to the reel hubs on each end of the tape. When the tape gets to the end, this clear leader allows infra red light to shine through and trip the End Sensor. The End Sensor is like a switch. When light shines on it, the switch is on. When there is no light, the switch is off. This on/off information goes to the CPU where it is processed. During PLAY, RECORD or FAST FORWARD if the Supply End Sensor is tripped, the VCR goes into REWIND mode. During REWIND, if the Takeup End Sensor is tripped, the VCR goes into STOP mode.
Symptoms:
11. REEL SENSORS - symptoms: nothing appears wrong in the tape transport except -
12. POWER SUPPLY INTERGRATED CIRCUITS (I.C.) - in cases where a VCR is dead and nothing seems to work, the power I.C. is a good suspect. It is the largest I.C. chip on the power supply board. Sometimes it is the only I.C. on the board. If you have a voltmeter, you may find that the 5 volt line on the I.C. is missing. Be sure to use an isolation transformer or GFCI when working on power supplies. Some soldering is required to make this repair.
In binding situations, the carriage may have been bent by some heavy object on top of the VCR. Often, it can be bent back easily. In cases of broken parts see if they can be repaired or glued if replacements are not available.
The easiest solution is to replace the entire carriage. It's an easy task on most VCRs. Most retail in the $25 - 35 range. I would not waste much time on trying to salvage one if knew I could buy a new one at these prices. But if it starts getting over $40, you might want to try harder to salvage the defective unit. For further information see Trouble Shooting the Cassette Carriage.
14. MODE SWITCH - the mode switch is a sensor that reports to the CPU. It senses all the positions of the moving mechanism. An average VCR mode switch has three switches in a sealed unit (that is why it's called a switch). As the mechanism moves, the switches open and close at different intervals. The CPU sees this as three channels of pulsed data and can determine what position the mechanism is in from this. If this sounds a little complicated, all you really need to know is what the symptoms are when it fails.
Failure is caused by one or more of the intermal switches not making reliable contact. It affects the travel of the moving mechanism. Usually if the CPU gets bad data during loadup, it will issue an unload command. The tape appears to be loading normally and then mysteriously unloads. It always starts out intermittant, and progressively gets worse. Sometimes, however, the mechanism will load up but stop in the wrong place without unloading. It may play at the wrong speed, the tension arm may not be correctly positioned causing picture distortions or it might just shut off. Repeatedly pressing play may get it to work in early failure stages, but eventually it will fail comepletely.
The key symptom to look for is 'incomplete travel of the moving mechanism'. A simple test is to locate the master cam gear (usually the largest gear in the VCR) while the failure is still intermittant and see if it stops in the same place everytime. Making reference marks (a magic marker is best) on the gear after pressing play and again after pressing eject makes this easier to see. Now load and unload the tape by pressing play and eject about 20 times (yes, this takes a while). If the gear stops in a different place just once, the mode switch is most likely defective.
15. INTERMITTENT RECORD TIMER - the following assumes you can record manually.
When you program your VCR to record your favorite TV show and later when you sit down to watch it, you discover it didn't record anything at all. This can be frustrating. You double check your programming procedures and you are positive you did it right. After all, you have probably successfully done this numerous times before over the years.
There are actually very few problems associated with the electronic parts in timer circuits. What is very common are marginal mechanical defects. A marginal defect is one that occasionally occurs. You may have not even noticed it, but in manual modes, if you ever had to press RECORD more than once to get it to go. You have such a defect.
It can be caused by a variety mechanical defects. Likely possibilities are mode switches, slipping load belts, marginal defective idlers, intermittent record safety switches, etc.
In event the record timer simply does not work and you are positive you are programing it correctly, it is most likely an electronic part failure (which is rare).
These 15 problems are the most common defects that repair shops see from VCRs made in the 80's. You could say they are also somewhat common to all VCRs. In event your problem does not show up in our database, there is a good chance it may be one of these. Out of all the hundreds of things in a VCR that could fail, it usually turns out to be one of these 15. You could have one of these problems and not even know it.
Many of the following are just too common to be placed in the Database Pages. For example, a reel belt on a capstan reel drive mechanism (found in over 90% of all VCRs) will develop the same symptoms in nearly all of them. It would be redundant for us to post this problem for all of them.
A good place to start if the Database Page doesn't help you, look this page over if your VCR was made in the 80's or the Top 10 Defects of the 90's and see if you are experiencing some of these symptoms. If so, there is a high likelyhood that may be it.
As a good educational approach, it's a good idea to familiarize yourself with these defects and identify where these parts are located in your VCR. That is what professionals do. They make an effort to become very familiar with common defects and don't waste much time on things that rarely fail. When there is a problem, common sense should tell you, it's much more likely (not always) to be something common.
15 Common Problems
1. Dirty Heads2. Idler
3. Belts
4. CPU Reset
5. Capstan Bearings
6. Roller Guides
7. Antenna Block
8. Foreign Objects Caught in Mechanisms
9. Relays
10. Tape End Sensors
11. Reel Sensors
12. Power Supply Integrated Circuits (I.C.)
13. Cassette Carriages
14. Mode Switch
15. Record Timer
1. DIRTY HEADS - symptoms:
- Sound is OK
- Picture is snowy. All areas of the picture have equal amounts of snow and the intensity of the snow varies depending on how dirty the heads are. Often it can be so snowy you can't see the picture.
- If your VCR has video muting (blue screen appears when no picture information is present), you will have a solid blue screen.
- It happened suddenly. It did not start out a little snowy and get progressively worse over a period of months. Everything was fine and suddenly everything went to snow.
- Picture went out when tape got snarled up in the machine.
With these symptoms, it's most likely your video heads are clogged. This happens most frequently when you rent movies. A certain number of previous renters have defective VCRs that can put substancial contaminents on the tape. You rent that movie and guess what? Your heads are now gunked up.
THE CURE - clean the heads. There are several ways this can be done. Believe it or not, the easiest, is to play an ordinary tape in the VCR for an hour. No, you won't be able to see the picture, so do something else to keep yourself occupied while it plays. Over a period of time the tape removes particles from the heads and restores your picture to normal. The scrubbing action of the video head spinning at 1800 RPM is what makes this possible. Surprisingly, this works about 2/3rds the time. You might also want to try one of the special Head Cleaning Cassettes. In event all else fails, you will have to open it up and physically clean the heads with swabs and cleaning fluid. If done incorrectly, this can ruin the upper drum assembly so be sure to read the section on VCR CLEANING before proceeding.
2. IDLER - symptoms:
- Eats tapes. Capstan pulls tape off the supply reel but the takeup side can't reel it in.
- Won't rewind, sometimes intermittent.
- Shuts off sometimes.
- In early failure stages, while playing, the take-up reel inside the cassette may behave erratically.
- When you press stop, the guide rollers retract without pulling in the tape.
THE PROBLEM - worn idler. Older VCRs have an idler that uses a rubber tire. Over the years, a slow chemical reaction occurs on the surface of the tire. This process results in a glazed surface, causing loss of traction. With a dummie cartridge you can see that the idler does engage the reel table, but if you grab the reel table with your hand, you find there is little or no torque. Without traction, the tire only slips against the reel table. If you push the idler into the reel table with your finger, it will work, but only as long as you keep your finger on it. Often all you need to do is replace the tire.
The tire can be easily removed. It's not glued or permanently fastened in any way. A small flatblade screw driver is a big help in removing the old one. In fact, you can turn it inside out and remount it that way. But since there are no treads on the inside wall and the fact the rubber has a lot of years of deterioration on it, you will be lucky to get a few months out of it. But at least you can still use your VCR in the meantime.
Newer VCRs have a gear instead of a tire. Although gears are much more reliable they still have problems. Usually becoming warped or loosing tension. The plastic retaining cap over the spring sometimes cracks. Without sufficient tension, the idler tends to get caught between the reels. This can be easily seen if you have a dummie cartridge. Gear driven idlers are one piece, so replacement involves the entire idler.
3. BELTS - symptoms:
- Reel belts - an early sign of reel belt weakness is when a T-120 cassette (6 hours) during rewind shuts off before it rewinds all the way. Cassettes with less tape work normal. This belt causes few other problems.
- Tape load belts - VCR may load tape around video drum. At that point insufficient traction results in not being able to complete the load cycle. CPU then issues a shutdown command. Sometimes these belts may squeel when slipping.
- Flat capstan belts - these belts will work fine until they physically fall off.
- Cassette carriage belts - rarely ever fail
- Counter belts - these are usually extra thin belts that are used to turn the counter or the reel senser pulley. The VCR will shut down if the counter is not changing or incrementing. Usually found on older VCRs.
4. CPU RESET - do you know where the reset button is on your VCR? If you say there is no such thing, we have a surprise for you. No, it's not a red button on the back, but you can still operate it without even openning your VCR. Simply by removing the AC power plug for about 30 seconds and then plugging it back in again. This resets the CPU. Turning the VCR off with the power button won't work; it must be unplugged.
This can solve a number of problems. Any time your VCR appears to be dead or doesn't respond to anything, try resetting it. Any time it behaves weird, like your channel indicator locks up or your clock goes to all 8's, try resetting it. This phenomenon occurs a lot more often than most people think. The primary cause is believed to be static electricity and power surges. You know that feeling you get when you walk across a staticy carpet and touch something like a door knob. It seems like it shocks your finger tip off. This electricity can also rearrange the digits inside your VCRs CPU. Fortunately, resetting fixes most of these problems.
5. CAPSTAN BEARINGS - symptoms:
- VCR may be playing fine and then suddenly the tape speed slows and eventually shuts off (noise bars are traveling though the picture vertically when this is occurring). The audio slows and may waver.
- The picture may also suddenly freeze (as if someone pressed the pause button), and then shut off.
- Press play and the VCR will go again, but for a much shorter time and stop again.
- The problem always appears on the SP speed and almost never on the EP speed.
- Bearing may emit a squeaking noise.
- Put a drop of oil on the bearing and run it a few minutes. If a substance that looks like black pepper comes up out of the bearing, you definately have a bad bearing.
The easiest way to positively identify a bad bearing is to put one small drop of oil on it and see if the symptoms vanish. It's easy to get to from the top. The capstan shaft comes up through it. Sometimes there is an oil seal on top of it. You can usually pry it up slightly and to get the oil underneath it. Remember, just a drop! Be sure no oil goes up the shaft. That is not good for the pinch roller or the tape. It might be a good idea to wipe the shaft good with a lint free paper towel or rag. The oil may even fix it for a few months, but eventually the bearing will need to be replaced.
6. ROLLER GUIDES - symptoms: Horizontal lines in picture. Tracking control won't cure it.
- Set screws come loose allowing height adjustment to wander. To confirm, grab the roller guide with your finger and thumb and see if it can be easily twisted. If so, a re-alignment is in order.
- Tape is running below the shelf on the video drum. Height adjustments are tight and the Roller Guide is tight against the V-stop. Solution - there are two press fit pieces in the roller guide assembly that have slipped. Rebond the parts and re-align.
- Angle pin on roller guide assembly missing. If they are loose, there is a good chance they will stay in until the first time you turn the VCR over to remove screws or whatever. With the cover off, confirm their presence. If missing, they usually stay in the machine somewhere. If found, simply put a small drop of super glue on the pin and press it into the hole on the assembly.
- Roller guide not making contact with V-stop. Usually caused by a linkage problem or foreign object caught in the V-stop.
7. ANTENNA BLOCK - symptom: coax connector falls off. This can happen if someone yanks on the coax cable a little too hard. Also some VCRs are manufactured so cheaply these days that it is possible they can fall off all by themselves over time. Unfortunately, you just can not glue these back on again. These are attached to a metal box inside the VCR. Inside the box is a circuit board usually consisting of the modulator circuits. When these connectors come off they must be reattached from inside the metal modulator box. It can be done, however, but it requires good soldering skills and can be very time consumming. It is usually much easier to replace the entire modulator itself. Sometimes it's refered to as the Modulator Block.
8. FOREIGN OBJECTS CAUGHT IN MECHANISMS - these objects come from two different sources. Those that get in there by accident, like labels comming off cassettes; and things that get in there by small kids, things like toys, rocks, crayons and food. When one kid was asked why he put a sandwich inside the VCR, his answer was he did not want the cat to get it. Top loaders are more prone to strange objects because whatever is on top has a chance of accidently falling in. Usually these objects cause mechanism jams that trip your VCRs shutdown mechanisms. Anything caught in the roller guide slides will not allow the guides to load up correctly, causing a poor jumpy picture with noisy lines in it. With the cover off, a careful examination of the mechanical mechanisms will usually reveal any foreign objects that do not belong inside. Simply removing them is usually all that is necessary to comeplete the repair.
9. RELAYS - often found on older VCRs, relays are notorious for causing trouble. They were commonly used in head switching and audio circuits. The problems are mostly with the relay contacts. Over the years, the surfaces of the contacts degrade until they reach a point where they can no longer complete a circuit. Head switching relays were standard in older four head VCRs. The position of the relay determines which pair of heads to use. A typical symptom of a bad head switch relay is a good picture at one speed, but distorted on another. What happens is that when the relay is in one position, it is makeing good contact for both heads. But in the other, only one head is getting a good connection. You can usually confirm a bad relay by pressing on it to see if it momentarily corrects the problem. Audio relays were used mostly in portable VCRs and are the first thing you suspect when there is no sound or does not record sound. Some soldering is required to complete this repair.
10. TAPE END SENSORS - all VCRs have two of them. One for supply and one for takeup. They have this name because their job is to sense the end of the tape. Operation is based on a beam of light that comes from the center of the cassette, goes through it, and hits the End Sensor. Depending on whether the beam hits tape or clear tape leader, determines if the sensor is tripped or not. For this discussion it may be helpful to have a VHS cassette in front of you to observe.
The large round hole you see in the center of the bottom side is for an infra red lamp to poke up into it when the cassette loads into position inside the VCR. It shoots a beam of infra red light through the cassette in two different directions, exiting through a small hole on opposite ends. These holes can be seen if you if you open the cassette lid (you will have to release the catch on the right end). From there, the light travels on to the End Sensors on the carriage side plates.
Inside the cassette, notice the clear leader that attaches to the reel hubs on each end of the tape. When the tape gets to the end, this clear leader allows infra red light to shine through and trip the End Sensor. The End Sensor is like a switch. When light shines on it, the switch is on. When there is no light, the switch is off. This on/off information goes to the CPU where it is processed. During PLAY, RECORD or FAST FORWARD if the Supply End Sensor is tripped, the VCR goes into REWIND mode. During REWIND, if the Takeup End Sensor is tripped, the VCR goes into STOP mode.
Symptoms:
- VCR mysteriously goes into REWIND mode while playing.
- Tape ends comming off the hubs inside cassettes. With cassette rewinding, observe the tape as it gets to the end. It should stop gracefully. If it continues to struggle, it's most likely the sensor is defective.
- While trying to load a cassette, the VCR ejects it. Some VCRs use these sensors to tell the CPU if there is a cassette loaded. If a sensor is failing, the CPU thinks there is a cassette already loaded.
- Cassette loaded indicator (if it has one) may be illuminated with no cassette inside.
- If you have a voltmeter, measure the two pins on the sensor. One is ground and the other should be about 5 volts with no light on the sensor. With light on the sensor, it drops to near zero volts. With your finger as close as possible to sensor, cover and uncover the sensor and see if the voltage varies like that.
- Warning! With the top cover off, room light can confuse troubleshooting efforts. End Sensors were designed to work with the infra red lamp. However, room light can also affect them . It goes straight into the sensor and alters voltage readings. Instead of getting near zero to about 5 volts, you might get something like near zero to about 2 volts and think you have a defective sensor. Be careful. There is a listing in the database for sensitivity with the top cover off. Following are a couple suggestions you may want to adhere to:
- Make sure there is no sunlight in the room. Sunlight contains a huge amount of infra red light. Close the curtains or wait until nightfall if necessary.
- Use as little light as possible. For example, use only one small lamp and place it clear across the room. Shield your work from the light with cardboard. Tape it in place if necessary.
11. REEL SENSORS - symptoms: nothing appears wrong in the tape transport except -
- VCR shuts off after about 5 seconds, counter is not changing. Definately a defective reel sensor.
- VCR shuts off after about 5 seconds, counter is changing. Most VCRs use just one reel sensor under the takeup reel. However, some use two. It's possible the other one could still be the culprit.
- The fact that the VCR works normally for about 5 seconds before shutdown, is a strong clue for a defective reel sensor.
12. POWER SUPPLY INTERGRATED CIRCUITS (I.C.) - in cases where a VCR is dead and nothing seems to work, the power I.C. is a good suspect. It is the largest I.C. chip on the power supply board. Sometimes it is the only I.C. on the board. If you have a voltmeter, you may find that the 5 volt line on the I.C. is missing. Be sure to use an isolation transformer or GFCI when working on power supplies. Some soldering is required to make this repair.
- You hear a clicking noise when power is applied or inserting a cassette.
- Cassette tray on carriage is crooked. If you are lucky, maybe a carriage gear just jumped a tooth.
- Cassette does not go all the way down.
- Cassette does not seat firmly on gaging pins after loading.
- You see broken pieces in carriage assembly.
- Cassette binds, or does not go in when trying to insert.
- Cassette binds or gets stuck while loading under power.
- Cassette does not eject all the way.
- Cassette lid does not open. Cassette opener spring may have sprung.
- Cassette motor is defective.
- Someone forcibly removed a cassette that would not eject.
In binding situations, the carriage may have been bent by some heavy object on top of the VCR. Often, it can be bent back easily. In cases of broken parts see if they can be repaired or glued if replacements are not available.
The easiest solution is to replace the entire carriage. It's an easy task on most VCRs. Most retail in the $25 - 35 range. I would not waste much time on trying to salvage one if knew I could buy a new one at these prices. But if it starts getting over $40, you might want to try harder to salvage the defective unit. For further information see Trouble Shooting the Cassette Carriage.
14. MODE SWITCH - the mode switch is a sensor that reports to the CPU. It senses all the positions of the moving mechanism. An average VCR mode switch has three switches in a sealed unit (that is why it's called a switch). As the mechanism moves, the switches open and close at different intervals. The CPU sees this as three channels of pulsed data and can determine what position the mechanism is in from this. If this sounds a little complicated, all you really need to know is what the symptoms are when it fails.
Failure is caused by one or more of the intermal switches not making reliable contact. It affects the travel of the moving mechanism. Usually if the CPU gets bad data during loadup, it will issue an unload command. The tape appears to be loading normally and then mysteriously unloads. It always starts out intermittant, and progressively gets worse. Sometimes, however, the mechanism will load up but stop in the wrong place without unloading. It may play at the wrong speed, the tension arm may not be correctly positioned causing picture distortions or it might just shut off. Repeatedly pressing play may get it to work in early failure stages, but eventually it will fail comepletely.
The key symptom to look for is 'incomplete travel of the moving mechanism'. A simple test is to locate the master cam gear (usually the largest gear in the VCR) while the failure is still intermittant and see if it stops in the same place everytime. Making reference marks (a magic marker is best) on the gear after pressing play and again after pressing eject makes this easier to see. Now load and unload the tape by pressing play and eject about 20 times (yes, this takes a while). If the gear stops in a different place just once, the mode switch is most likely defective.
15. INTERMITTENT RECORD TIMER - the following assumes you can record manually.
When you program your VCR to record your favorite TV show and later when you sit down to watch it, you discover it didn't record anything at all. This can be frustrating. You double check your programming procedures and you are positive you did it right. After all, you have probably successfully done this numerous times before over the years.
There are actually very few problems associated with the electronic parts in timer circuits. What is very common are marginal mechanical defects. A marginal defect is one that occasionally occurs. You may have not even noticed it, but in manual modes, if you ever had to press RECORD more than once to get it to go. You have such a defect.
It can be caused by a variety mechanical defects. Likely possibilities are mode switches, slipping load belts, marginal defective idlers, intermittent record safety switches, etc.
In event the record timer simply does not work and you are positive you are programing it correctly, it is most likely an electronic part failure (which is rare).
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