Remind me here have you repaired anything else in this channel other then this SIP? because there certainly is something amiss elsewhere, like leaky drivers since the SIP feeds them directly. Do you get that same voltage with the SIP card out of circuit on those pins on the PC board???
Logic says if you replaced the SIP with a known good one and still have issues then You still have other issues after the SIP card like the drivers leaking etc...
The amps design is SIP card, drivers, and then outputs, so its got to be forward of the SIP card. I have seen these blow back like this and it cost everything in the channel to solve the issue.
Did you replace any of the MPSA56 and MPA06 drivers ??? They tend not to survive channel failure and they can feedback voltage to the SIP??? let me know what you find. They cost three cents each in bulk quantity, and a lot of amps use them so I buy bulk, and tend to replace them as it takes less time then testing them. 
About that bad sip card. No, the solder did not stick lol. Just curious what I can do with through hole parts to repair it. I'm thinking to-92 bjt and a 330R 1/4w. Can I use a BC556 to-92 in place of the BC856 sot-23? That is the closest thing I can find.
Base goes to pin4 of sip card. Collector goes to pin15. And emitter goes to 330R then to collector of Q4 in the referenced pic. Would that work?
Base goes to pin4 of sip card. Collector goes to pin15. And emitter goes to 330R then to collector of Q4 in the referenced pic. Would that work?
Try it and see what you get....I have seen a few similar attempts like your speaking about. I never did any real time testing to see what the results were.
I just usually replaced the module to be 100% original design in my repair work. As the years have rolled by these modules will be even worse to come by then they are now < planned obsolescence >
I have some of my own boards made but don't want to run the insurance risks involved with using them, except in my very own amps. I suggest you start buying up all the broken Art and PC series and some of the PCX series amps if you want to have spare parts on hand in the future....
I just usually replaced the module to be 100% original design in my repair work. As the years have rolled by these modules will be even worse to come by then they are now < planned obsolescence >
I have some of my own boards made but don't want to run the insurance risks involved with using them, except in my very own amps. I suggest you start buying up all the broken Art and PC series and some of the PCX series amps if you want to have spare parts on hand in the future....
I would like to make a final update! Everything seems to be working well! I had two driver transistors shorted out(MPSA06s.) One of them was the one that feeds the output trsnsistor that had the short, and the other one was to the paired output transistor. I changed all of the MPSA06s and MPSA56s on that side of the board. I also resoldered quite a few components in that area that had really crappy solder joints.
I powered the amp up with a current limiter and 5 amp fuse. It pulls right around 1.2a now after setting bias. The dc offset is in adjustable range. I just need to take the time to do it...
I would like to thank 1moreamp and Perry for all of their help. I would also like to thank anyone else who has helped me out on this!
I powered the amp up with a current limiter and 5 amp fuse. It pulls right around 1.2a now after setting bias. The dc offset is in adjustable range. I just need to take the time to do it...
I would like to thank 1moreamp and Perry for all of their help. I would also like to thank anyone else who has helped me out on this!
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