optimus STAV-3170 Help

On Wed, 19 Nov 2008 16:37:06 -0500, "Gary L. Woodruff" put finger to keyboard and composed:

That's a Radioshack product.

The following info may not help much but FWIW ...

Here is an exploded view:

This is the parts list:

The service manual details are ...

Cat.No. Description NP Part #

----------------------------------------------

10828648 MANUAL,SERVICE 31-3026 MS3103026

Radioshack support page:

- Franc Zabkar

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The original transistors were 2SC3281 and 2SA1302, they were replaced with NTE2328 and NTE2329. The other components replaced were Q512, D520, D522, R612, R614. any help would be greatly appreciated. Thanks, Gary

My guess is DC shorted out whatever couples the protect circuit to the output or there is too much DC offset on the repaired channel. Do some voltage / current comparisons with the other channel provided it is ok and not harboring some underlying problems too.

Thanks for the help. I measure Dc offset @ the speaker terminals and get

12.6 mv & 14.5 mv. The left channel is fine and does not trip protection. My biggest problem is the way the hs mounts to the board the foil side of the board is not accessible to probe. This makes comparing voltages between the two channels impossible. If i could locate a print it would make life much easier!

thanks, Gary

Yeah they can be a pain in the ass. A print would be nice for trouble shooting in this case. I've done manufacturer warranty for the majors including Radio Shack and know where your coming from in regards to getting access to the foil side. At one time I had an HS jig that I made to give the devices some sinking while allowing exposure to the foil side on certain models.

You are hopefully not using your customer speakers but using known good speakers and or a dummy load?

Thanks, I am using my bench speakers to test. (I have even swapped channels just to be sure I didn't loose a speaker!).