Your advise on "shotgun" repair should probably be its own PSA video. Whenever I have a synth on my bench (a much less frequent event these days), I will often make prophylactic replacements of known-problematic parts while I've got it apart. The key to success is proper skills -- if you don't have the technique or the proper tools then we get the unfortunate results we see here. Keep up the good work!
I repaired a pair of these 4 voice programmers, many years ago. PIA, in that they were not the typical uP controlled systems I had become comfortable with, they were something ancient and bizarre, TTL logic running in an endless loop. And all the ICs soldered in place. So much fun. I had to brute force grind it out, chip by chip replacement until they started working. Never want to do that again!
If I'm not mistaken, 6508's are now obsolete, scarce, and expensive to replace. Not only do I have an EVS but also a Prophet-5 Rev 2, for which the latter I purchased a "RAM Upgrade" to have 6508's in case my EVS needs them. I'm very tempted to devise an SEM PSP "upgrade" project to essentially consolidate much of the circuitry into less PCB's. Oh well, only if time allows. EDIT: Honestly, I don't consider refurb kits to be "shotgun repairing" provided the SAME approach to discrete component diagnosis/rework/repair/servicing principles are followed. In the case you showed above, the previous worker appears to have been too hasty during their process.
Same here. I also don't consider a refurb kit a "shotgun" repair since the components have been carefully chosen and are typically replacing components that are known to eventually fail. There is a subtle difference between a "shotgun" repair and prophylactic replacement of components that have a high probability of near-future failure.
Incredible. Even when defective, and recorded through the speakers and the camera's microphone, this synth sounds awesome! @10:34 why did you grey out the video on some parts of the channel board for voice 1 and 2 there? Anyway, as always, interesting video repair. Thanks for sharing.
Great video, I am currently trying to fix a two voice. One odd question: What are those black screws called that connect the modules to the frame? Seams to be an "imperial" thread and I don't know where to get them in Europe. Can I order them from your webshop?
