weird power problem - Digitech GNX 4

[randers1]

DrGonz thx for the bump request. Jazz P Bass, will check the voltages tomorrow

[randers1]

From the top down, off of L36, 3.31V, off of L50, 3.35v, off of L51, 4.93v, I had trouble getting a reading off of U37, I think it flashed 12 or 14v one time. I was unable to duplicate.

[Jazz P Bass]

You obviously have a boot problem.
Seeing that the voltages seem o/k, my next step would be the timing crystal.
Again, this thing is a computer in a pedal box.
Not an east thing to try and repair.

[g1]

Were you checking those voltages when it was not starting up?
You will need to do checks when faulty boot, then compare to working boot. That will be tough as you will have to keep letting it cool down to get the fault condition.
Aside from the voltages Jazz mentioned, check the reset lines of U5 and U11 (pg.7).

[randers1]

I didn't check the values on a hung restart, I will do that next. I realize it must be tough to fix since the authorized shop couldn't, I really appreciate your guys time and interest. Unfortunately I am going out of town for the next week and a half, I will be back the Monday after Thanksgiving and recheck the voltages. I hope you all have a great holiday and I will post that Monday night.

[tlm2408]

Just signed up to offer some help. I had the same thing happen to me about 7 years ago. It turned out to be the power transformer, it wasn't putting out enough current anymore. Replaced it and it's been going strong ever since. I hope this helps