techknight
Well-known member
Double-check your soldering work.
Went back over any suspect joints and one step passed, no more Sad Mac error or chime.Double-check your soldering work.
Bad SWIM probably, and the line is a broken trace to the LCD from the controller, or potentially between the SRAM and controller IC.
Well curiouser and curiouser said Alice...
Ran a soldering iron around the SWIM and SCSI and VIDEO packages just to see if there was a bridge or dry joint. Connected power and the voltage and current is all over the place and PMGR reset has no effect, Q16 gets hot. Not my bench supply as another gave the same results.
Guess it’s one more demon to exorcise.
View attachment 39566
Remove the SWIM. its bad.
that’s an infrared of Q16 showing the temperature after about a minute with power on.with that image, I dont know what im looking at .
and no, thats not normal. theres something upstream drawing an excessive amount of current.
This happened after you reworked solder? Check to make sure you didnt bridge anything.
well the fact that you just resoldered SWIM and SCSI, doenst mean you didnt form a short there.
Same with the video chip.
and solder bridges now create a whole set of new unknowns that make troubleshooting that much more difficult. :-( Because that's how one fries shit. (been there, done that).
all PLCCs follow the convention. Pin 1 is in the middle and it goes counter clockwise.
QFP/TQFP is different.