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Pioneer SX-650 restoration suggestions

bberkom

bberkom

AK Subscriber
Subscriber
I just picked up a functional but rough-looking SX-650 for pretty cheap in a craigslist deal. See photos. It is fully functional, and I get good sound out of both channels. There is a little too much background noise, but I haven't cleaned it up yet. I am going to rebuild a solid wood case for it since the vinyl one is rough, but the faceplate and knobs are all accounted for and only have some minor scratches. I am going to end up taking it to a tech to have the tuner fixed and have them go over it. But I want to do some cosmetic work first.

The back of the unit shows a good bit of surface rust around the rca and speaker connection. I plan to try to get this panel off, but if that is too much work, I am just going to leave it on and go at it with some vinegar and a wire brush/steel wool. There is a lot of rust around the terminals, and I plan to open the bottom and clean from the inside as well. Will deoxit be enough to clean the rca and speaker terminals?

I am also wondering how to best remove all of the dirt and crud that is covering much of the inside of the unit. I want to make sure I don't disturb anything on the circuit boards or use any cleaner that I shouldn't use.

Thanks for any suggestions on what to do with this unit. Already sounds pretty good and seems to have good power.
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Wow - looks like a great project! Can't wait to see your "after" pics.
To clean mine, I put it on a slope outside with the transformer side high. Then used diluted simple green and a paint brush and washed it off with with a light stream of water, avoiding the transformer and tuner gang.
As for wood, I replaced the vinyl with walnut veneer (PSA self stick) and replaced the 2 small front/side pieces with genuine walnut. Painted the grill with matt black from a can.
Pioneer sx650 restore (1).jpg
 
bluehills5 said:
Wow - looks like a great project! Can't wait to see your "after" pics.
To clean mine, I put it on a slope outside with the transformer side high. Then used diluted simple green and a paint brush and washed it off with with a light stream of water, avoiding the transformer and tuner gang.
As for wood, I replaced the vinyl with walnut veneer (PSA self stick) and replaced the 2 small front/side pieces with genuine walnut. Painted the grill with matt black from a can.
View attachment 816347
Click to expand...

Thanks for the tips. I started cleaning last night, and it looks mich better already. I need to give it another round, but it's looking like it'll turn out great.
 
I finally finished cleaning up this receiver, at least for now. I really really like it. It's built really well (minus the power switch) and it sounds powerful. Lots of low end. The noise floor is really low on it, which surprised me considering how much corrosion was on its exterior. I didn't know what to think about the little transistor packs, but they sound great. I made a new case out of solid walnut. The top sticks up above the faceplate by a bit because I wanted to make the panel a little thicker since I was using solid wood and not plywood.

I did end up having to disassemble the power switch and sand the burned contacts clean again. My switch was one with two rivets I had to file off. To reassemble, I just flipped the filed rivets around and superglued them back in. It held really well, and I figure if it fails again I'll just end up bypassing it somehow anyways. the only other issue is the broken tuner cord. The tuner works fine when I rotate it by hand, I just didn't feel like messing with the cord yet since I rarely listen to radio.

The one question mark I have is about a large ceramic capacitor, a little over 1" diameter in a rubber casing, that fell out of the receiver when I turned it upside down and then back over. See photo below. It's hard to read, but I think it says .01 +- 10%, 125 VAC. I looked in the schematic, but I couldn't find a capacitor with these values, and everything electrical is working in the receiver as far as I know. It almost doesn't look as though it has been used since the leads are long and don't really protrude from the rubber case. If anyone knows what this is, let me know!

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Found where that loose cap goes. It bridges a couple of terminals by the transformer. Got it back in place now. Anyone know what it does?
 
bberkom said:
Found where that loose cap goes. It bridges a couple of terminals by the transformer. Got it back in place now. Anyone know what it does?
Click to expand...
Snubber cap and usually is fused but you said transformer side not outlet side so 86 the fuse.
 
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