SX-650 Main Supply Capacitors

[John Walther]

Hi. I have a question about recapping a SX-650. I removed the two main supply caps but didn’t realize that the black wire is to ground on one and to positive on the other. Would someone happen to remember: do the orange wires go to neg or pos on the left capacitor? And do the brown wires go to neg or pos on the right cap? I can't tell from the schematic. Thanks, John​

 

[Ray66]

I happen to have a stock SX-650 open on my bench now. Hopefully this photo helps John. Front of the receiver is to the left.

 

[John Walther]

Thank you so much for this. That's exactly what I needed!

 

[John Walther]

Hi. Do you happen to still have the 650 open? I'm having a problem matching my Tuner board with the schematic. Thank you, John

 

[Ray66]

Let me know what you need to see. I'm currently out of town but could post more pics later this week.

 

[John Walther]

Mainly like the picture I sent. If it’s not the same, I’m screwed, because the schematic I have is very different. Thanks!

 

[John Walther]

Hi guys and girls. I have a SX-650 and the Tuner board doesn’t match the schematic. Does anyone know of an alternative schematic that I can get? Thanks, John

 

[John Walther]

I may be reading the schematic wrong. But the schematic shows 6 capacitors to the right of the selector switch and I only have four on the receiver itself.

 

[John Walther]

I’m sure I’m reading the schematic wrong because the capacitors on the actual board don’t match the schematic. so I’m having trouble finding what goes where. If you could take some closeups of the tuner board capacitors, I’d really appreciate it.

 

[EastPoint]

You should be able to match the old capacitance with the new one. The little blue blob tantalum caps will have capacitance written on them.

 

[John Walther]

Yes, I could do that if I hadn't made a noob move and taken some out without replacing them right away. Of course, I don't remember what they were. I was counting on the schematic to tell me. Thanks anyway!

 

[petehall347]

work out which board is fitted

 

[John Walther]

I just printed that out and I'll try to match it to the board. Thanks!

 

[Ray66]

Here you go John, a couple images of my SX-650 tuner PCB. The service manual I got from HiFiEngine lists that PCB as AWE-075-A. Mine is stamped AWE-075-D. Not sure what difference there is (if any) between versions. I haven't done any work on this unit yet so assuming it's original.

 

[Ray66]

Yes, I could do that if I hadn't made a noob move and taken some out without replacing them right away. Of course, I don't remember what they were. I was counting on the schematic to tell me. Thanks anyway!

Unfortunately, the info in the service manuals is not always accurate. The general guidance is to replace capacitors with the same value/voltage rating as what was found on the original, even if it does not match what is specified in the parts list of the SM. Of course this applies to units that have not been worked on previously. I can't speak for others but I typically only replace one at a time. SInce electrolytic and tantalum capacitors are typically polarized I mark each with a sharpie to keep track of the orientation as you can't count on the screen art on the PCB to be correct either. The SM I have lists 17 electrolytic (CEA) caps and 19 tantalum (CSZA) caps on AWE-075. I would replace the tantalums with low-leakage electrolytics as they are failure prone. Hope this helps.

 

[John Walther]

Here you go John, a couple images of my SX-650 tuner PCB. The service manual I got from HiFiEngine lists that PCB as AWE-075-A. Mine is stamped AWE-075-D. Not sure what difference there is (if any) between versions. I haven't done any work on this unit yet so assuming it's original.

Thanks, that should at least help.

 

[Ian C.]

just because it's timely, and stocks change... would you mind sharing mouser SKU you used for those main caps?

 

[John Walther]

I got them as a package on eBay from peace.love.and.music . I’m sure he’d be happy to help.