I Fix, Something Else Breaks RCA VDT-350 - Videokarma.org TV - Video

TinCanAlley · #1 06-13-2025, 05:22 PM

So I got the solenoid to work again, but upon testing, I realized the image is now crap. On a new TV I get some of the image, but on older TV I get something I can't explain, so I made a couple quick videos and put them on youtube since I can't upload videos here.

The image is scrambled, but audio is fine. In my work on the VCR I made no changes to the transport or altered any factory adjustments. All belts and idler tires are good. I figure if it were something with the belts or idler, the audio would show signs of speed issues, etc.

Anyway, here are two links. Let me know what you think.

https://youtu.be/EhxZMZdORog

https://youtu.be/LJndD4nBZc8

Username1 · #2 06-14-2025, 06:00 AM

.

That is an old unit, so most likely that machine has a separate audio head. As for the
picture, I would bet the drum speed is off, clean the tape heads on the drum first,
after that you need to get that 1 1/2" thick manual that they use to print for
fixing those units and start looking at drum speed regulation.... I would turn
the H. Hold on the tv and see if you can get it to lock, If it does, is the
color present, and is it locked...... Have fun.... Nice old unit. I got
an older one I still have not turned on yet... Make that 2......
If it locks and the picture is not complete, lots of white
drop outs, I would clean the heads a few times.....
Don't go up and down, clean with the direction
of spin only.......

.

TinCanAlley · #3 06-14-2025, 03:16 PM

Quote:

Originally Posted by Username1

.

That is an old unit, so most likely that machine has a separate audio head. As for the
picture, I would bet the drum speed is off, clean the tape heads on the drum first,
after that you need to get that 1 1/2" thick manual that they use to print for
fixing those units and start looking at drum speed regulation.... I would turn
the H. Hold on the tv and see if you can get it to lock, If it does, is the
color present, and is it locked...... Have fun.... Nice old unit. I got
an older one I still have not turned on yet... Make that 2......
If it locks and the picture is not complete, lots of white
drop outs, I would clean the heads a few times.....
Don't go up and down, clean with the direction
of spin only.......

.

I have the Sams Photofacts SM and I believe it has all I might need. I believe the speed/timing belt is one that has three variants and I have the original. Before the solenoid issue, the image was good, so I'm not sure why it is acting up now. I connected it to an LG OLED via tuner and the picture was better than the old Zenith, but seemed as though it was pulsing.

I'll get out the tightly wrapped swabs I've used in the past and the 99% IPA and go over the heads and tape path. I'll also demagnetize it. Hopefully that's all it requires.

redk9258 · #4 06-15-2025, 12:02 PM

Quote:

Originally Posted by TinCanAlley

So I got the solenoid to work again....

How did you get it working?

TinCanAlley · #5 06-15-2025, 06:38 PM

Quote:

Originally Posted by redk9258

How did you get it working?

Well I thought it to the a transistor on the transport board, but upon testing once removed, it tested good, so I put it back in. I then figured it had to be something in the pause circuit as that would release the solenoid. I then realized that there is a port on the back for a wired pause button. I cleaned it and the contacts on the pause arms that get connected when the pause button is pressed. It worked after that, so I don't know if it was the contacts or the port. Should have done one then the other, but you know how that goes.

Now I just need to get back to the image I had before the solenoid issue. I am about to clean the tape path and heads. Wish me luck.

Tube TV · #6 07-06-2025, 12:17 PM

I'm also thInking head speed issues, judging by the horizontal lines. I have also seen this with feed issues but the unit is usually damaging the tape if it's that bad. You'd hear it.

Nice machine. I had a few years ago.

TinCanAlley · #7 12-12-2025, 12:03 PM

I wish I could get a decent audio recording of what I'm hearing, but I just can't seem to get it. I'll try to describe the sound, but I'm sure I'll fail at it.

When I play a tape, there is a sound that I'm assuming is coming from either the transport or video head. It is whirring sound that pulsates. It's not a sound that sounds like a bearing or such, it sounds like it would be normal if not for the pulsating part.

If anyone has any suggestions on how to record such a sound, I would appreciate it. I don't know why I can hear it, but not record it.

TinCanAlley · #8 12-12-2025, 12:23 PM

I managed to record the sound, but it had to be in a video. Seems the audio recorder on my phone is crap. So here's a link to a youtube video. Hopefully someone can tell me where it might be coming from and if it is part of the issues I'm having with playback.

https://youtu.be/2zWpIipukhQ