Fully balanced TDA1305 - eBay

SSassen

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Paid Member
2005-03-11 12:03 pm
Beta Zeticuly
www.disney.com
Hello fellow DIYers,

A friend dropped off a DIY DAC based on stuffed PCB he purchased off of eBay, see attached picture. Unfortunately the DAC has developed a defect, one channel (left) drops out and distorts quite badly, which is why he asked me to repair it.

I looked it over, checked voltages etc. swapped out the opamps just to be sure, but the defect persists.

Currently I’m looking for a schematic, as without that it will take me hours to draw it up from the PCB. So if anyone has more info I’d appreciate hearing from you, thanks!
 

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SSassen

Member
Paid Member
2005-03-11 12:03 pm
Beta Zeticuly
www.disney.com
Its likely to be a faulty dac chip, i had a similar problem with parallel tda1543 dac. Only way to know is remove a dac and hope its the faulty one, if its not remove the other one and replace them both.

Thanks, I'm leaning in that direction too, but this would be a lot easier with a schematic though, as I hate going the trail and error route.
 
I'm intrigued by the array of 12 SOIC14 chips on the left hand side - is it a FIFO array or some such?


The rest of the circuit is easy to follow from the layout surely? 4 DACs and filters in the main section, 2 DACs or ADCs on the TOSLINK-S/PDIF section bottom left. You don't need a schematic, just the pinouts for the important chips so you can follow the signal path.