Found these inside a non-working 71B

[Dave Frederickson]

(03-14-2018 09:15 PM)MikeSD Wrote:  What Ref is that? And which bank is it? The only 2 devices I touched are the on back right in the photo above, and the back left (Math), in the photo above. No other RAMs were touched.

Mike, you do have a copy of the schematics, right? They can be found in the H/W IDS and the Service Manual.

To answer your question, U9 is Port(0.3), but how do you know if that's where the issue is? If there were a short on U6 between DIN and DOUT, the Port(.01) RAM, then it may go undetected and U7 would be configured as Port(.01).

I think all you can be certain of is that only three of the four 4k modules were detected.

Dave