TAS SAW BOARD, NO SOUNDS

I have a TAS Saw board that has on sounds.  I have tested all three sub boards in it,  sound board, sound power and R2LC.  All test fine in other locos.  Even swapped other known good sound boards and R2LC from two other locos. Still no sounds on the SAW board. The speaker also tests good.  All other functions, lights, couplers, and motor drivers on the SAW board work fine, just no sounds.  Did a reset on the board using known good boards to reset Code #8 (All Diesels with Smoke........) no luck.        Any insights appreciated.    J

Original Post

Pin out the mother board and make sure the volume control pot functions.  IF all else checked out, only the mother board, wiring and volume pot remain. G

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GGG posted:

Pin out the mother board and make sure the volume control pot functions.  IF all else checked out, only the mother board, wiring and volume pot remain. G

G, thanks for the response,  the pot checks out,  connected it to another SAW board.  Think I'll pull off the heat sink and run down all the pins.  I noticed that the IC under the R2LC is a microprocessor, does a board reset affect that processor or does all the action occur on the R2LC ?  I try to practice good ESD prevention but never know and doubt that sellers of used boards make any effort to these ends at all. Been lucky so far bought 20 or so used board and so far this is the first glitch.  J

GGG posted:

Pin out the mother board and make sure the volume control pot functions.  IF all else checked out, only the mother board, wiring and volume pot remain. G

G, Found the problem, No power to sounds power supply pins 1-2. fond a hair line crack in the trace leading to the two pins.  All functions working fine now.    Thanks,  J

Looking at the place the crack was in my best guess at the cause is the way the triacs mount under the board creates a fulcrum, when you push the sub-boards on it flexes the main board. I noticed this on the first TAS SAW that I installed back in the spring. I have been somewhat careful about supporting the main board when I install the sub boards but since I bought this off eBay I can't know how the previous owner removed and installed boards.  J

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