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-   -   RCA VKP-950 pickup spindle not spinning? (https://www.digitalfaq.com/forum/vcr-repair/11015-rca-vkp-950-a.html)

olePigeon 09-22-2020 03:09 PM

RCA VKP-950 pickup spindle not spinning?
 
So I bought an RCA VKP-950 VCR described as "just needs new belts." Unfortunately it's not just new belts, and I've since discovered that someone else worked on it before me. So it looks like I bought someone else's garbage. Also, no technical manuals to be had and information on this particular model is scarce. :/

I was able to successfully get inside from a video review of a VJP-900.

I've cleaned off all the liquified belts and replaced them, replaced the pinch roller, replaced the idler, and I've since re-greased the moving metal parts (I only have lithium at the moment, I'm looking for a cheap source for graphite grease.)

So my initial problem was that the supply spindle made a horrible grinding noise. See here. I discovered that the spindle was too low and was grinding against the metal chassis. When I took the spindle off, it looked to me like it was missing a washer. It had 1 thin washer, 1 thicker washer, a tiny ball bearing, then 1 more thin washer. Seemed like it was missing a thick washer again to get it the right height. So I bought an assortment of washers from my local hardware store, and got it to the right height.

So now it doesn't grind. Shortly after fixing the supply spindle, that one wouldn't turn either. Then when I took it apart again to try a different washer, it started working fine again.

However, my problem is still the pickup spindle. It doesn't turn. If I apply just a tiny bit of pressure on the idler, it works fine. See here.

Does anyone have any ideas why the idler isn't engaging the pickup spindle? I'm also curious why the supply spindle appears to be working now, but not before.

I've never worked on a VCR repair and I don't have a technical manual, so I'm flying blind on this.

On an unrelated note, the sensor (erase head?) in the back-left of the machine near the read head wasn't connected to the circuit board. It had 2 cold solder joints and fell right off. So I soldered that back on. No idea if it's working or not since I haven't been able to play a tape yet.

Thanks for any help.

Edit: Also, if anyone is in the South Bay Area, California, I'd also be willing to pay to have an expert fix it. I've called all the shops in my area, and no one can or wants to fix it. :(

lordsmurf 09-22-2020 03:24 PM

Quote:

Originally Posted by olePigeon (Post 71628)
So I bought an RCA VKP-950 VCR

Why? :question:

Nostalgia?
Just to own an antique VCR?
If so, that's fine.

Because this isn't a good model to be used for any kind of tape transfer work.

I want to clear that up before beginning the arduous process of a VCR repair. No need to waste time with junk.

olePigeon 09-22-2020 03:27 PM

Nostalgia. It's not for transfer. I have an RCA Dimensia TV. I wanted the Selectavision to go with it.

lordsmurf 09-22-2020 04:17 PM

My guess is that somebody (unqualified) took apart that deck and had "extra parts". Probably a practice deck, somebody else's garbage as you've surmised.

One of the members here can probably help more than I can. My general VCR repair knowledge is somewhat shaky, I specialize in JVC S-VHS decks only. Some smart folks here.

olePigeon 09-22-2020 04:19 PM

OK, thanks. I'm hoping a veteran might be around to help. I feel like I'm 90% of the way there, if I can just figure out the takeup spindle :/

I'm going to try putting some rubber bands around either the idler or spindle and see if it helps at all.

lordsmurf 09-22-2020 04:25 PM

Quote:

Originally Posted by olePigeon (Post 71632)
I feel like I'm 90% of the way there,

That's my gut feeling as well. :congrats:

Hopefully somebody else will be along soon...

olePigeon 09-26-2020 02:24 AM

I'm gonna post here my progress so that it might help someone else.

So today I tried putting some extra girth on the roller, but when I plugged in the VCR, it wasn't barely getting power. Intermittently, actually. When it was powered, the idler couldn't push past the stop to engage the pickup reel.

I began checking the voltages with my multimeter. It was getting power fine, powered fine from the transformer. Blindly checked at some of the test points, and the power was fluctuating all over the place (and sometimes failing completely.) I didn't need a schematic to know that when it's fluctuating by 3 to 4 volts, something's bad.

I figured it's probably bad capacitors. That kind of behavior is often from bad caps, but could also be a faulty transistor or other diode.

So I spent an hour disassembling it, finally got to the main power board under all the stuff ... and those caps are toast! They leaked all over the board. I'm a bit worried about the traces. So I'm going to head to the store and hope they have the right capacitors I need. I'll need to replace them and check all the traces. :/ So that's going to take a while.

My current theory is that the VCR wasn't getting enough power to the idler. So even with a new idler, the motor couldn't provide enough push. That would also explain why the supply spindle seemed to randomly work fine.


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