Black Widow repair using Fluke

I'm going to sit down with these schematics and follow what you posted when I'm a bit more awake, but it already has helped me understand better. Thanks so much for the explanation!!!
 
The Fluke's RAM test keys (short or long) will test a range of addresses, writing and then reading back data to each of them. You could use it on a single address by entering the same starting and ending addresses like so:

RAM SHORT 0 Enter/Yes 0 Enter/Yes

but for our purposes we want to do a read from one address and a write to a different address, and do them separately. So for the read we use the Read key in the upper center group:

READ 0

The results come back instantly, or if the Fluke is unable to do the read it asks if you want to Loop and you can press Enter/Yes or Cancel/No. Otherwise the Fluke displays the data it got, and you can still repeat the operation continuously by pressing the Loop key in the lower center group.

For writing the process is the same except you must tell the Fluke what data you'd like to write. In our case we're writing FF to address 07FF so the sequence is:

WRITE @ 7FF Enter/Yes = FF Enter/Yes

with the Fluke supplying the @ and = symbols for you. As with the manual read operation, it will probably work (or think it worked) unless there is a problem with one of the busses. And since it's not verifying the operation, the only feedback you get is "OK." As above, you can have the Fluke continuously repeat whatever it just finished by pressing the Loop key.

Another useful key is Repeat, which will redo the most recent operation once per keypress. It can help with pins that are very active during looping. You can stop the looping, put the logic probe on a pin and know its resting state, and then press Repeat to see what effect the operation has.
 
I'm going to sit down with these schematics and follow what you posted when I'm a bit more awake, but it already has helped me understand better. Thanks so much for the explanation!!!

same here, some very helpful tips for using the fluke are being discussed
 
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