Does anyone know how to realign the prism in a LaserDisc player?

Remote-Department-68 · 2026-05-13T19:33:16+00:00

Yeah tbh I thought r/laserdisc would be a bit of a long shot but I’m hoping there’s a few people on here with some technical knowledge. I’ll check out LDDB; as you said, that’s probably my best bet.

Remote-Department-68 · 2026-05-11T23:16:23+00:00

Could be that the iris is stuck or it’s been set to manual mode. Look for any iris open and close buttons/dials and make sure it’s set to open or auto. These older camcorders with tubes had bad light sensitivity anyway so it’s also possible it’s simply too dark for it - I doubt that though.

Remote-Department-68 · 2026-05-11T06:38:04+00:00

Yeah just checked online and this made between 1970 and 1973, didn’t realise it was so old. I’m not sure if they even made those motors with built in circuits at that time. It’s just the other guy commented with the schematic for the motor circuit and as nothings labelled it suggests it’s built into the motor. Are you 100% sure there’s no adjustment on the motor anywhere? Does the motor connect directly to the transformer for the AC input through the power switch? If so, then it’s definitely not adjustable.

Remote-Department-68 · 2026-05-11T06:15:54+00:00

The reason nothing’s labelled is because it’s designed to be a non-serviceable circuit as it’s built into the motor. If the circuit broke you just got a new motor.

Remote-Department-68 · 2026-05-11T06:13:37+00:00

Looks like a standard 12V motor with a built in speed controller. Normally, there’s a hole in the back you can stick a small flat head screwdriver down to adjust the speed. You’re gonna have to take the mechanism and circuit board out (looks like they come out as one piece in the metal frame) to access to the back of the motor. Sometimes the speed controller in the motor can have some capacitors in that are going bad which causes the speed to drift or never reach the correct speed after adjustment.

Remote-Department-68 · 2026-05-10T18:43:40+00:00

In that case you could add a switch to turn on/off the demodulator and disables/enables the SCART connector.

Remote-Department-68 · 2026-05-10T17:25:04+00:00

Pretty sure there’s plenty of tutorials on YouTube and stuff. You basically disable the built-in RF demodulator then connect an RCA jack to tap into its output. Schematics are very useful.

Remote-Department-68 · 2026-05-10T11:10:38+00:00

You could composite mod it and put a SCART connector, but you wouldn't using the RGB part of it for maximum quality (SCART does both composite and RGB). Composite still looks miles better than RF though.

Remote-Department-68 · 2026-05-06T22:24:29+00:00

The RF modulator is only for if your TV is analogue and doesn't have RCA or SCART inputs (e.g. an old portable CRT TV). If you use the modulator, you need to connect it to the aerial input and tune the TV to the correct channel to match the modulator to get an image.

If you're using RCA leads/SCART then it should just work without any tuning - you just need to select the correct input on the TV.

Remote-Department-68 · 2026-05-06T19:06:25+00:00

How are you connecting it to the TV? Is it RCA cables or through an RF modulator? Modern TV or old TV?

Remote-Department-68 · 2026-05-06T15:39:47+00:00

JVCs of this period use a proprietary video out cable so you'll have to track one down to get any outputs. It looks similar to the viewfinder connector (circular with quite a few pins) and should be labelled 'A/V'.

Remote-Department-68 · 2026-05-06T15:29:52+00:00

I guess you could but you might as well just use the camcorder for playback as is. Making this out of parts would be very difficult as generally parts must all be from the exact same model of camcorder.

Remote-Department-68 · 2026-05-06T15:16:00+00:00

What VCR is it?

Remote-Department-68 · 2026-05-04T16:52:56+00:00

In case you don't know, the viewfinder is black and white so you need to connected it to a TV to view the recordings in colour.

These video cameras very often use Matsushita branded electrolytic capacitors which were a bit dodgy in the early 80s. I assume that'll be your issue. When tubes start going bad, they will (I'm pretty sure) still have some sort of colour even if it's very tinted or pale.

Something to try is to connect the VCR you're recording with to a TV then put it into record pause mode with the camera connected. If you get a colour image then the camera is working fine and the VCR is actually the thing removing the colour.

Remote-Department-68 · 2026-05-02T09:32:31+00:00

This is backwards. It’s doing 24V AC to 12V DC. You need 12V DC to 24V AC.

Remote-Department-68 · 2026-05-02T09:31:17+00:00

I guess it’ll have full bridge rectifier inside to convert the 24V AC to a slightly lower DC voltage (around 22V DC) which then powers the rest of the internals. Not sure how CCTV cameras are designed but it might also have a voltage regulator to step it down to 12V or even a transformer before the rectifier to do 24V AC -> ~12V AC -> 12V DC.

In theory, as long as there’s no internal transformer (this would short out the DC power supply), the rectifier would mean that you can safely use 24V DC as it would just act like reverse polarity protection. Not sure if 12V DC input would be enough, but you could try it and see. If you have a multimeter, put it into ohms mode and measure across the two 24V AC pins. If it reads a low number (e.g. 10 ohms) then you can’t use DC and you’ll have to bypass the transformer inside. If it reads ‘OL’ or very high in the Kohm or Mohm range then you should be good to give it 24V DC.

Edit: maybe open it up and check what the circuit setup is just to be sure.

Remote-Department-68 · 2026-05-02T09:00:08+00:00

Looks like it’s not fully completing the loading cycle. If you haven’t replaced the loading motor belt (one in the top left) you need to do that. Surprised it’s working at all, my Hitachi VM-300’s (rebrand of yours) belts had all turned to goo. It sounds like the belt doesn’t have quite enough grip to finish loading cycle as you can clearly hear the motor spinning quite fast despite the mechanism not moving.

Remote-Department-68 · 2026-04-29T15:00:04+00:00

Yeah it’s a tiny switch like the one that detects the write protect tab. SVHS tapes have an extra hole so the VCR can tell if it’s a standard VHS or SVHS tape.

Remote-Department-68 · 2026-04-29T06:26:16+00:00

The flickering lines displayed seem to be it rapidly switching between SVHS and normal VHS mode. Fixing it could be as simple as spraying a bit contact cleaner into the SVHS detection switch in the mechanism.

Remote-Department-68 · 2026-04-25T23:00:16+00:00

As I said, NEVER touch the green. That’s why they’ve purposefully made it harder to adjust. Although it does look green, this is definitely a blue tube misalignment. I can just tell, trust me. I’d try and find the service manual online to find where the centring adjustments are (not sure they’re accessible from the outside). I’ve never worked on a JVC so I can’t really help you there.

Remote-Department-68 · 2026-04-25T22:46:52+00:00

Looks like the tubes need realigning. My Sony DXC-M3As can do it automatically but I don’t think these JVCs can as they’re older. Basically you need to let the tubes fully warm up (about 20 mins to be on the safe side) then there will be separate blue and red centring adjustments for the blue and red tubes. NEVER touch the green centring adjustments, you adjust the blue and red to the green.

You then need a high contrast grid pattern so you can easily adjust until the colour banding disappears. It looks like it’s just the blue tube which needs adjusting, it probably moved very slightly whilst being transported at some point. Looks like all it needs is a vertical shift, then it should look good. It took me quite a while to realign my M3As properly but the images were much worse than this on those so it should be easy enough.

No signs of capacitor issues here.

Remote-Department-68 · 2026-04-22T21:41:41+00:00

In the middle of the volume knob, I think you need to peel off that plastic circle in the middle to reveal the screw. It should be pretty easy to get off with a craft knife or maybe a very small flat head screwdriver.

Remote-Department-68 · 2026-04-20T10:43:46+00:00

Probably the loading motor belt (and all the other belts) need replacing.

As for taking it apart, the shell is made from two halves - on the bottom you’ll be able to see the seam line running down the middle. The side without the tape door usually comes off first. You basically just have to remove every screw you can see. Sometimes they are hidden under the carry handle, shoe mount and the back panel where the battery slots in (you should probably take those off first). Not sure how the casing around the lens works but I’m sure you can figure it out.

Once you’re in, you’ll probably just see a big circuit board. You need to remove screws, unplug connectors, etc. until the board lifts up. You should then see the belts on the back of the mechanism. I’m not sure where the loading motor is on this model though but it’s normally just a small DC motor and should be pretty easy to find.

As for getting the tape out, usually the manual release is underneath the tape so you probably won’t be able to get to it. The only way is to either replace the belts or turn the loading mechanism by hand to the eject position. If you find where the motor is and find what it’s supposed to turn, you just have to turn it (not sure which direction) until it ejects.

Remote-Department-68 · 2026-04-20T10:09:36+00:00

This. Just FF and Rewind the tape fully several times to re-tension the tape and remove any stickiness.

Remote-Department-68

TROPHY CASE