Advice / Schems on a General Electricrp 1561a
 

Sorry the title got messed up. Its a rp 1561a model.
So I bought this for a couple bucks at a church rummage.
When you plug it in, all it does is buzz/hum at a constant rate, and moving the volume adjustment does not change the volume of said buzzing.

Anyone know where to start?
Need a schem too.
Looks like the guy in the pic.

http://www.videokarma.org/attachment...1&d=1359022991

The first thing to do is change the capacitors in the power supply. That's what's causing the buzzing. After you get those changed, see how it works. If you have any experience working on radios and such, you might not need a schematic.

You need to replace the electrolytic filter capacitors most likely. Then you can discover what else it needs.

Is this the guy to replace? Is this a bundle of capacitors? Never worked on anything this old, but I've recapped a couple CRT arcade monitors, and replaced caps on LCD screens.

Not sure what's up with this guy here.

http://www.videokarma.org/attachment...1&d=1359107104

http://www.videokarma.org/attachment...1&d=1359107105

When I first saw the thing, I thought it was solid state. Then I looked again and it has the V-M changer. Looks like that vacuum cleaner tone arm.

Yep, that's the filter capacitor. It's a three section. so you will need to get three seperate caps and tie the ground wires together. Looks like you might be able to make a bundle out of them, wrap in black tape and reuse the mounting bracket if you don't know how to restuff caps. Should be an easy fix.

Pull the chassis and make sure the coupling capacitors aren't paper.. If they are change them too. That changer will need a bit of work, degrease, lube, and maybe a new idler. This record player will be nice foor old rock 45s

Schematic is available in Beitmans 1963 manual.
Available at makearadio.com. Follow the prompts.

Sweet. Thanks. :banana:

Hopefully I can work on her the next couple days.
Here she is the day of her acquisition last summer.

http://www.videokarma.org/attachment...1&d=1359198305

That filter capacitor was paper. Strange.

Anyway, of course Radio Shack didn't have the capacitors I required.
A MFD is the same rating as a uf, correct? I'm having alot of trouble finding these. Do I just need a non-electrolytic?

The u is actually the Greek letter mu, meaning micro. You do need an electrolytic cap, because of the high microfarad values. Radio Shack doesn't handle high voltage caps. You have to buy them from Justradios or another on-line supplier. Also, with the 200 mfd cap, you have to parallel two 100's.
Also, a good place to get high value, high capacitance caps are from a scrap computer power supply or a scrap solid state color TV board.
Paper cased multi section electrolytics were cheaper and easier to install on the production line.

So MFD and uf are the same, ok.
OK, I was under the impression no paper caps were electrolytic.

UPDATE:
So I replaced the caps, except a .47uf I forgot to order.... :(

It seems to mostly work now. I think the pots are pretty dirty. Also it seems to have issues on both channels. Sometimes one will be ok, then the other will be humming, quiet or distorted.

It's got one of those dual-needles for 78s and LPs. Anyone know how to tell if they are bad or where to get them?

Here's a youtube vid
http://www.youtube.com/watch?v=SFQ7N4kdxSw