Technics SA-500 restore.

hemiram

Active Member
If anyone can help me, thanks..

So I bought this SA-500 off Ebay. It works pretty much perfect, except it had a noisy tuning cap. Only one dial light worked. I bought a bunch of the LED 6v replacements, and took the unit to work with me so I could give it a general clean up. With just a damp rag, it looks pretty good on the outside, the knobs were just about perfect once the crud was off them. I think it looks great! The first rag I used looks horrible, just from cleaning up the outside.
7z5PBh.jpg

I took the bottom cover off and checked the filter cap leads to see what to order, and the two 10,000 uF 50v caps have conventional leads about an inch apart.
QnBLB2.jpg

I don't see anything that's a direct fit. Does anyone know if there is a direct replacement somewhere? When I look, I see ones the same size and value with either "snap in" leads or lugs. The pic above is after some cleaning, it's really nasty inside. I wiped off the top of the transformer and heat sink. And now for the problem. Before I started the cleaning, the one dial light bulb worked but now, I have no lights at all. Voltmeter shows no voltage on the dial lights now. Is there a fuse on them I'm not seeing?
The receiver works 100% now, I used Deoxit on the tuning cap and took a brush and cleaned the fuzz out of the plates and the lower freqs are crunch free now. Other than some of the silver coming off the switches and some stuff behind the dial glass/plastic, it's looking really good now. I like the knobs. I was disappointed to find out the switches are plastic. A couple of them have white spots where the silver has worn off.
0eiBlK.jpg
 
I'd search and download the service manual. The circuit for the bulbs will be there. Are you measuring AC with your meter?

Check if it uses 12V bulbs. Many receivers have an 8V circuit and 12V bulbs give a lower brightness.

I think those large caps are "snap in" type. Search for snap in capacitors. If you don't find the right lead spacing, it's easy to drill a new hole in the PCB, you can do it even twisting a small flat screwdriver.

I've painted plastic pieces with silver nail polish

http://cinecomi.com/wp-content/uplo...gns-and-tutorials-unique-nail-art-designs.jpg

Many times you can also disassemble the front and flip the levers upside down. The bottom side is usually in better shape.
 
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Why would you want to replace the main filter caps? If you don't hear any 120Hz hum through the speakers there's no need to do that. Saves you a couple of bucks.
Nice unit by the way!
 
If anyone can help me, thanks..

And now for the problem. Before I started the cleaning, the one dial light bulb worked but now, I have no lights at all. Voltmeter shows no voltage on the dial lights now. Is there a fuse on them I'm not seeing?

FWIW, On my very different model receiver, the dial lights are fuzed with a very unremarkable length of bare fusible wire between two points on the chassis.. It would be very easy to break and very easy to miss. It looks exactly like the sort of thing that could be broken while dusting. I only found it because there was an extra fuze marked on the schematic that did not show up in the chassis.
 
Looks like I blew a fuse. I had a lot of problems, as the previous owner did, just getting the bulbs/LEDs in. 2 of the 3 bulbs were hanging out and only partially inserted. When I put the new LEDS in, I"m pretty sure I shorted out the lights and one of the fuses is "frosty". Of course, fuses are hard to find now, especially slow blows, so I just ordered 5 each of the 4 listed on the schematic.They should be here Wed, and I will use some pliers or a hemostat to put the LEDS in this time, preventing shorting them out by twisting the tops of them, as I did before. The ones I bought seem very fragile.

As far as the filter caps go, it does have a very slight hum, and they don't cost all that much. I don't care if the new ones are smaller in size, but I don't like to drill new holes if I don't have to.

Thanks for the replies!
 
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