Troubleshooting AS1424 spectrum analyser

[msknight]

I've got a feeling that I'm on a hiding to nothing here, but here goes :-)

AS1424 audio spectrum analyser. This one is version 6.1 and I think is prior to 2016.

I've built the kit but it won't power on. I've checked the cable and I've also checked my socket soldering, and they're good. However, I'm not sure how to start troubleshooting... and I know, for a beginner like me, perhaps I've chosen the wrong thing to start going to town with, but nothing ventured, nothing learned.

I think I've got a problem because the chip looks to have been lasered, (it was pre-soldered to the board) but it seems to be programmable, so there's a chance that someone might know what it is likely to be... and therefore which pins to check for power. The only spec given for that chip in the assembly instructions is, "CPU."

I do have a v7 working, and another v7 that I'm in the process of building, so I'm starting to think that there's a problem with the 6.1 that I won't be able to solve.

Part of me is also thinking that the LEDs are controlled by the chips at the top which I think are ULN2003 and 74HC595, so I'm wondering that with a small arduino or something, I might be able to rescue this rather than chuck it in the bin... but that's further down the line.

Anyway... I'm good at getting myself into these scrapes (cough) opportunities to learn and grow... and I'd be grateful for any thoughts please.