Pioneer SX-737 refurbish project - Page 1
Forum section: electronics / repair

author: Arty30
author_rank: Regular Contributor
timestamp: April 12, 2022, 12:35:43 am
content: Hi all, I recently scored a pioneer SX-737 off the curb for free and I am working on getting it back up to its former(ish) glory. It's absolutely filthy and crusty but nothing that wont clean off. it has over 40 years of small scratches and worn paint in places but its in great shape still, plus I can't complain since it was free. The main thing is that it powers on and works in one channel, the other is weak or just carrying over from the other channel. I also want to know if anyone has any experience with reapplying white lettering onto glass dial faces, the FM muting and mono buttons on the right side have had their labelling worn off. I have come ideas but I haven't tried anything yet. Any tips and ideas are appreciated, I'll keep updating as this project progresses.

author: bob91343
author_rank: Super Contributor
timestamp: April 12, 2022, 03:36:53 am
content: I am guessing that your weak channel is due to the Tape Monitor switch needing cleaning.

author: Arty30
author_rank: Regular Contributor
timestamp: April 12, 2022, 01:31:07 pm
content: yeah I figured that too, I haven't cleaned the controls yet so I'll get to that once I get the thick grime off the outside.

author: GLouie
author_rank: Regular Contributor
timestamp: April 13, 2022, 04:53:13 am
content: Quote from: bob91343 on April 12, 2022, 03:36:53 amThat, or maybe the speaker relay contacts, if it has them.

author: Arty30
author_rank: Regular Contributor
timestamp: April 14, 2022, 02:19:49 am
content: I does have a relay, I'll keep that in mind.

author: andy2000
author_rank: Frequent Contributor
timestamp: April 14, 2022, 10:03:25 pm
content: That's old enough to need some, or all new electrolytic capacitors. I would definitely at least spot check a representative sample of caps to see how they are holding up. Often you will find that one particular brand/model cap has aged badly, and you can get away with just replacing those. If it's difficult to work on, then you might as well replace all of them.I recently worked on a similar age Pioneer integrated amp which had numerous bad caps. Some of them were signal coupling caps which caused one channel to be weak. There were enough bad caps that I just went ahead and replaced them all.

author: james_s
author_rank: Super Contributor
timestamp: April 14, 2022, 10:12:33 pm
content: An option for the labels is toner transfer. You can also get waterslide decal film that can be printed on, I've used it on model airplanes. Obviously I think it makes sense to get it fully working before you worry about cosmetic details though.

author: Arty30
author_rank: Regular Contributor
timestamp: April 14, 2022, 11:54:23 pm
content: I tested it today and it seems to work just fine, both channels sound good with no noticeable distortion or volume difference, I think it was just so grimy and had sat in a humid environment (central Florida, USA) for so long that the switches and selectors were corroded. I'll put it on my good speakers soon to check for sure. as for the caps the main filters are Elnas and all others are Nippon Chemicons which I know are decent quality, but I'll do a test sampling. I have considered toner transfer or waterslide decals but my main question is how I can get white lettering, as its a black background. My first plausible idea was to print a negative, where its essentially white text on black paper, and attach that to the backside of the glass dial window, but I'm not sure so I'll keep looking into it. Thanks for all the comments thus far.

author: Arty30
author_rank: Regular Contributor
timestamp: April 17, 2022, 09:41:14 pm
content: All right, I think this project is about wrapped up. This thing sounds amazing with a pair of good speakers, and looks amazing with an LED backlight kit installed. For the missing labels on the glass I ended up with using clear glue to attach a piece of paper to the inside of the glass, unfortunately waterslide decal film didn't work with such a small decal. thank you all for your tips and suggestions.