Fluke 9010a just died

I don't know if you guys have this same experience, but I haven't touched
my 9010a for months. I went to fix my Midway Double Play last night and
for some reason now this tester won't work. Just for no reason at
all. AUUUGH!

Fortunately, I happen to have my Fluke 90 series Z80 tester. I'm hoping
someone on this list has had to become familiar with the 9010a service
manual. If you feel like giving me a hand, you might want to refer to
page 4-32 - 4-35.

Here's the testing I've done so far.

Symptoms - 9010a powers up but only displays a zero with an 'x' in the
middle. The keyboard doesn't work except when toggling the probe pulses
high or low.

9010a self test - won't respond to key presses.

90 series uP tests:
Bus Test - Pass
Ramp Test - Pass
Memory Test - C000-FFFF Pass
Memory Soak - C000-FFFF Fails - Hmmmmm. Is this normal?

I/O verify - writes data to certain I/O addresses and then reads the
data to check to see if it comes back the same.

The Pod/Probe PIA section passes the I/O verify test (100C0 - 100C3)
The Display/Keyboard section Fails the I/O verify test (10080-10081).
The Magnetic Tape controller also fails (100A0 - 100A1).

What appears to be happening is whatever gets written to the
display/keyboard assembly will not get read back correctly.

Here's something weird. If I do a write @ 10081 Data=00 (reset command to
the display/keyboard) and loop it for a while, then immediately reset the
"mainframe" (as they like to call it). For about a second the Normal
display comes up and then blanks out.

I can also send commands to the magnetic tape controller and it will
rewind. So it seems like the 'writes' are all working, the reads are
screwy.

I'm mainly concerned about the keyboard/display assembly. Does anyone
have any advice on this one? Could I have a bad ram chip somewhere? I
already tried replacing the Z80 microprocessor.

Thanks...

Matt

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Received on Sat Sep 29 10:35:13 2001