NEW? STK0029 Modules

[CT Jim]

So, all in all, resolved. First time I have had any issues with a China shipper, everything in the past has been as described.
But working thru the clipped English explanations was getting frustrating, finally said.."Paypal refund is a one clik option! Complete the refund or I'll open another eb case."
In two hours it was resolved. I'll use these as testers and if the unit runs again, I'll look around at some better sources for a stable set, but I may just relegate this to being a bench unit.

 

[zebulon1]

The best way to T/S the amp boards with the modules is to check every component for serviceability (This procedure holds true for any amp board that had some catastrophic failure). I remove all the caps, diodes and transistors. Lift the resistor legs and check all the values against the scat and compare the values to the other half (channel). This way a guy knows that all the components are good, and the board is ready for the modules. If you don't you are going to chase your tail.
You may already know this but I think the modules get a bad rap because the guys throw a module in (Because someone tells them it's the module) without checking the board for issues. The module goes bad because of driver stage issues and then they get labeled counterfeit.

 

[CT Jim]

I know you're right about the proper procedural way, but I have other projects I prefer to spend time on. This unit was running when I first saw it, and then as someone was playing with the volume to "hear" whether they wanted to buy the speakers, it suddenly went dead. I bought it inexpensively because I do like the old Pioneers. No smoke, no fuses, nothing obvious. I still think it was a 4 ohm load that caused the failure!

However, before I pull anything, I will still do the pin readings so I have a better idea where I stand, and will check it out as time allows!

 

[JimL1]

OK, I admit it, I'm a glutton for punishment! Anyway, I ordered a couple "new" stk0029 modules for a SX-580 of which I received some testing advice in another thread, but now I have to ask...do these modules look NEW or are they all in this type of shape considering? I see a small what looks like a lump of solder on pin 5 on the right piece? They look a little rough of course compared to what they said was new in the picture, an eba. delight of course

How do I check these before installing? The old ones, still installed are Darlington units, but I didn't want to put a boatload into this unit. I would like to compare the units installed against the uninstalled ones, or I can remove the old ones, and do the same test on each? It's more of getting it to work again versus restoration. Now that I have these direct from China, if they work I probably don't care, however, I do listen to advice here on AK and generally feel happy with what I achieve with help!

Thanks
Jim

Never buy from UTC. I bought about 10 from then and none worked. I will never buy from them again. I had to contact my credit card company in order to get a refund. I bought several on ebay and they always worked well so far

 

[rcs16]

Wow and sad the STK saga continues. I agree it is most probable, the low Z speakers that cause the modules to fail.

I bought several on ebay and they always worked well so far

Why do you not say where/who you bought them from? so that AK folks stand half a chance of getting working units.

I know it is sort of expensive, time consuming and a bit of work to use the replacement modules that I designed, but if you want the keep the units out of the scrap heap, it is imo the best option to keep them going for many years yet. You will never have the worry about hooking them up to low Z speakers again or if it is too loud you will pop the STKs. Even if you get a failure it is a cheap $5 fix.