Good afternoon All,
I have a a TIU (Rev L) that appears to have be reworked (fiddled-with?) by someone, previously. I have a failed output to repair. Two of the four FETs on one of the variable channels were loose and the soldering was poor on all four. Zero flux cleanup was performed, and a few of the pads are damaged. I've done SOME pad and trace repair in the past, so I'm not too afraid of it. I'd like to confirm the FET connections with someone (GGG ,Gunrunnerjohn ?), if possible.
It appears that the FETs are operated in a parallel quad. There's a trace on the bottom side that seems to tie all gates together for some purpose. Is that correct? I presume that actual gate drive signal must come through small resistors from a prior stage. That's how we do it in amplifiers and DC converters, anyhow.
The TIU seems to be a three layer board. Is that correct? If so, repairing pads for plated through holes to the middle layer traces are going to be pretty tough.
A schematic sure would be nice. (Chuckles)
Thanks in advance for any advice or information.
