Latest Episode of Failure

[wally]

Since you have terminator power, all those parts, which are located near F3 on top and on the bottom of the PCB, are all likely good (L=ferrite choke inductor, D=SMT diode). To be sure, disconnect any internal hard drive and measure again, that voltage should still be there. Had that voltage been zero, it would have meant UI12 SCSI controller chip would lack power. Next, using the best magnification you have, inspect UI12 and nearby traces for C8 C9 C10 capacitor goo damage, and run the tip of a pin or needle between all pins and feedthrus that might have a microscopic short growing between adjacent copper. That's about all you can easily do short of trying still other SCSI devices with existing UI12, or replacing UI12.

 

[Mk.558]

L10: Continuity

L9: Continuity

L8: Continuity

D3: Bias working correctly (1.1xx measured at the 2K ohm scale, nothing in reverse)

F3: Continuity

Trace paths near SCSI controller chip: Fine, but area between C9 and C10 looks a bit sketchy. I'll report back with pictures if that helps.

EDIT: 2048x1536. Yes, that's why I didn't use my image of logic board for a capacitor trace reference diagram :disapprove:

http://i26.photobucket.com/albums/c113/Starofire/Random/faa842d1.jpg

 

[wally]

I do not see signs of capacitor goo corrosion in that area. The solder has not lost its shine nor turned black. There is the possibility that the recapping soldering could have caused a problem around C9 C10, or possibly underneath them. You can use an ohm meter to verify none of the traces from those feedthrus between C9 and UI12 connect to the terminals of C9 and C10, and that they continue along their individual ways under C9 C10 to where they go near UJ11.