RCA VDT625, no A/V audio when idle

[CPQ5360]

Hi folks,

A couple of days ago I picked up an RCA VDT625, and after some mechanical maintenance, I had it working great. However, last night it developed a strange fault, in that you can no longer hear whatever is plugged into the A/V ("camera") input when the VCR is idle. If I press the Record button (with or without pressing the Play button), I can hear it, and it records fine. If I play a tape, the playback audio is fine too. But when the machine is turned on and idle, it's deaf. No audio out the A/V out or the RF out.

Here's a video demonstrating the symptom:

https://twitter.com/themaritimegirl/...12760947957762

I was actually watching something through the A/V input when the fault occurred, and it just suddenly got really quiet for a few seconds before it dropped out altogether.

I've sprayed and worked the internal record-playback switches, I've worked the Tuner/Camera switch, I've cleaned the flux off of the audio board, and I've re-seated the connectors on the audio board. No dice. I'm worried that a component-level fault has occurred, and I can't even begin to troubleshoot it because I have no service manual, and my troubleshooting skills for something this complex are novice at best.

It actually doesn't limit the functionality of the VCR, because if I want to watch/listen to something connected to the A/V input, I can just press the Record button without pressing the Play button. But it bothers me that it's a function that was working fine for two days, and then is suddenly not working.

Any ideas what could be wrong, or where to start with troubleshooting? Anyone run into this issue before? Thanks!

[CPQ5360]

I have *just* been informed that, at least with other Panasonic-made VCRs of similar vintage, you're not supposed to hear the A/V input unless Record or Audio Dub is engaged. Which would mean that me originally being able to hear the A/V input was itself a fault, which has now cleared up as I've used the machine. And I'm the idiot trying to figure out what's wrong.

Can anyone else confirm this for me?

[damen]

That unit may use some of the small "sugar cube" size relays in the A/V switching circuits. If you have any of them, tap on them and see if anything changes.

[damen]

I've never heard of a VCR that didn't have audio in the idle mode. RCA even advertised that with a remote control VCR you could use it as a tuner box for a TV not equipped with remote to change channels.

[CPQ5360]

There *is* tuner audio. Just not audio at the Camera input until you enter Record or Audio Dub mode.

[dishdude]

On something of that vintage, I wouldn't be surprised if that were the normal operating characteristics. Those inputs and outputs would only be expected to be used with a camera or dubbing.

[probnot]

I remember being told the a lot of the first VCRs were like that (both JVC and Panasonic).

I think the idea was for it to operate similar to an audio cassette deck from a component stereo system. The tuner being pushed through end-to-end without record or audio dub would have been the unusual bit.

I guess it was decided pretty quickly that it was just easier to show whatever you were going to record regardless if any of the buttons were pressed.

[Ed in Tx]

never mind.

[CPQ5360]

If you read my original post, that was already covered.

Based on the opinions expressed here, it sounds like there's nothing actually wrong.