Quote from: lightfoot on January 03, 2014, 01:19:55 AM

Quote from: synapse on January 03, 2014, 01:04:00 AM

Quote from: lightfoot on January 02, 2014, 11:22:54 PM

Hm, yep that's the 4 amp 3.3 volt power supply. Out of curiosity what happens when you plug it in now?

Do you have a volt meter and know how to use it? I'd be really curious to see if the 1 volt power line is up; it feeds off the 12 volt supply line. If that's working and the 3.3 volt short could be cleared you could power the board up with a small bench supply and it might work again. But man that is a serious hack.

Speaking of serious hacks, I have a board coming in with a blown set of 1 volt FETs. I'm going to try powering it off the danger board with jumper wires; technically it might work. Then again the voltage drop might be too much but what the heck?

:-) Keeps me out of trouble.

C

I just get the red light near the power connector, none of the other LED's light up at the front or back.

I have a multimeter to test with. I just need to know where to test. I haven't had a chance to look at the board layout and see what is what.
I'ts certainly the most tightly packed board I have ever had to look at.

It's not too bad. Grab the schematics by googling for sc-mainboard-1.0, it's a PDF from BFL. Once opened take a look at the board layout. On the opposite side from the power plug (top side) you will see a square hole, then a space, then five more holes. Right by the JTAG port.

Those are the voltage test points. They are:

ground 1-volt 3.3-volts 5.0-volts 12 volts.

All reference to ground. See what you find with the board plugged in.

C

Ahh I see, they cut the board so close to those test points the silkscreen of gnd, 1v etc is missing.

OK at the test points I have: 1.01V, 0.0001V, 0V, 13.1V
should I have 5v?

Resistance between ground and:
1v = 41ohm
3.3v = 0.20 ohm
5v = 2.9k ohm
12V = 2k ohm

It's hard to tell if this is the burnt out u15 chip causing the short or something else as well causing this.
If Mr Teal thinks it might be hard to diagnose then it might not be worth removing u15 and RMA'ing instead.