Another iisi issue

[imactheknife]

Another board, another issue lol.. this board had a few blown diodes right in front of scsi connection. Removed, repaired traces. Both blew again. I fixed the one as i had another 2 ay diode. The other one is a 1 ay which i dont have a spare. What would cause these to blow, power surge?

 

[imactheknife]

Cy still seems to smoke with no diode present. I fixed q10 right beside it. It isn’t blowing up now

 

[imactheknife]

C40 that should say in last post

 

[imactheknife]

So no ideas where to look. The diodes replaced, the traces fixed. I am still getting sparking at top of q11 i think. There is no shorting. Was getting spark without diode on. Just not sure what’s happening. Is board beyond repair?

 

[imactheknife]

The board works fine otherwise. To be clear, this has to do with power from psu to the little molex that powers the hard drive. Something ib between is not happy.

 

[imactheknife]

all fixed. I think the cap goo from from c35 and c38 corroded the contacts and ate the trace of c33 and c37. I replaces the c33 and c37 with part from a parts board, put new caps on at c35 and c38 and all is well. Just in case anyone has issues like this in the future, it has been resolved. Amazing what leaky caps can do