VHS Recorders
You may have a stack of VHS tapes, but find that your VHS machine no longer works. This page sets out a few things you can try.
Summary
Although VHS recorders have long since been displaced by newer technologies, many people still have a stack of VHS tapes that they might wish to review before throwing them out, or transcribing any cherished ones. Perhaps you moved away from the format when your VHS recored started giving trouble, or maybe you power it up for the first time in years, and it fails. In either case there are a few things you can try.
Safety
- As with all mains powered devices, switch off and unplug from the mains before disassembling. Be aware that electrolytic capcitors in the power supply section can retain a dangerous charge long after switching off.
Initial triage
First of all, establish what functions still work (if any) and what don't.
Do you still have the remote control? If so, test the batteries with a multimeter and replace them if they read less than about 1.3V each. If they have leaked and caused the contacts in the batery compartment to corrode, your first job will be to clean them.
If you don't have the remote control, search online for the user manual. This should tell you how to operate your machine using the buttons on the front panel.
Does it still switch on, either with the remote or with the front panel power button? If so it should show something on the display, and hopefully you will be able to navigate the menus.
If it shows no sign of life, check the fuse in the mains plug. This will rarely be the problem but is an easy fix if it is. Assuming the fuse is ok, you will need to concentrate on the power supply section of the device.
If it powers on, will it accept a tape? If it immediately spits it out again, or jams, you will need to concentrate on the mechanical drive mechanism. If you have a head cleaning tape, try that. Simply cleaning the heads, the capstan and the tape guides might solve your problem.
If it plays a tape but with horizontal bands of snow across a (likely) unsteady picture, this means the tape tracking is out of alignment. With care, this is quite easy to adjust.
Removing the lid often simply involves removing one or two screws in each side, and/or one or several on the back, retaining the lid to the back panel. Identify the internal components. The power supply may be a separate board, perhaps with its own metal cover and is easy to identify, as the mains lead or a socket for a detachable mains lead goes straight into it.
The main logic board will have the rear panel sockets mounted on it. There may be a ribbon cable linking it to a board with the front panel display, controls and infra-red remote control receiver on it.
The mechanism is fairly complicated. Note in particular, the cam - a shiny cylinder set at a slight angle to the vertical, the capstan to drive the tape, and the tape guides. Take great care not to touch the surfaces of any of these with your fingers.
Check for any obvious problems. If there is a tape cassette stuck inside, maybe with tape tangled up, remove it with great care. In particular, take care not to strain any of the tape guides as to do so is likely to cause more tape jams in the future.
Look for any signs of overheating or charring on the main and power supply boards. If there is a fuse on the power supply board, test that.
Mechanical problems
Touching only the top, check that the cam spins completely freely. After a period of disuse the lubrication can sometimes congeal. You may only need to spin the cam by hand to free it, alternativey, a tiny drop of ligtht oil (such as sewing machine oil) may do the trick.
Clean the surface of the cam, the tape guides and the capstan with isopropyl alcohol on a cotton wool bud. Make sure no cotton fibres are left on any of those parts.
Check that any rubber drive belts haven't gone slack. It should be possible to obtain generic replacements, though fitting them might be tricky.
Taking care to keep fingers well away from the power supply, plug it in, switch it on, and try inserting a tape cassette. You should see two tape guides catch the tape then wrap it around the cam. The capstan should start to feed the tape as you press "Play". If that doesn't all happen, watch carefully to try to spot what is going wrong.
Adjusting the tape tracking alignment
With the tape loaded, you will see two guides, one each side of the cam, wrapping the tape around it. These have screw adjustments in the top. To get the best possible alignment you need an oscilloscope, but you can get a quite acceptable picture with the output connected to a TV. An old fashioned CRT TV makes the job considerably easier as the picture will jump around a lot more with a modern flat screen type.
Rather than describe the process here, you are recommended to seach on YouTube for "VHS tape alignment", which will throw up various vide guides describing how to do it.
Electrical problems
A simple thing to try is to disconnect and re-seat internal connectors.
Rectifier diodes and electrolytic capacitors in the power supply are the most likely components to fail. (Follow the links if you're not familiar with them and how to test them.)
Rectifier diodes are easily tested with a multimeter. There may be a set of four, or four in a 4-pin package. They are cheap to replace. If one or more have failed, this could have caused a fuse to blow.
Electrolytic capacitors can dry out over time. Consequently they may not show the classic symptoms of swelling or leaking, and may fail after a short period of use following a long a period of disuse.
The power supply may be required to provide several different voltages for the mechanical and electronic parts. These voltages may be marked on the power supply board next to a connector which connects it to the main logic board. If so, you can check these voltages wth a test meter (keeping fingers well away from the mains input).
External links
- External links (if any) as bullet points.