8 Sep
2015
8 Sep
'15
9:45 a.m.
From: Holm Tiffe
Anyway, thanks for the schematics
Eh, de nada.
I have the board running again. The fix was simple,
the xtal was bad.
You're lucky it was something so simple! (Although we've seen this kind
of thing before - I had that 11/23 with a bad crystal.)
I've got three dead 11/73 boards (from someone else), but none of them are
that easy. Different symptoms on all three, but I suspect the State Sequencer
gate array on all three. On one, at least, the ILOE latch control signal from
that gate array is sitting at 2V (which I seem to recall is characteristic of
a TTL input that's not being driven).
Maybe it's just some corrosion, and re-seating the gate array (if I can work
out how to unseat it - don't have the extraction tool) will fix it.
Otherwise, I'm SOL. At least the J11 there are spares for - that gate array
is surely umobtainium.
Noel
8 Sep
8 Sep
11:12 a.m.
Noel Chiappa wrote:
I do have an extraction tool, but was unable to extract the chips
out of the sockets w/o braking one socket... ok soldered in a new one
and put the chips back after cleaning the pins with a glass hair brush..
There is a german company that saves chips from old pcb's, If you are sure
that you need a chip, try to search the numbers in ther database:
http://demotronic.de/
I found at least the gate array type..
Search for all numbers, not only the "real" type.
Regrads,
Holm
--
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Freiberger Stra?e 42, 09600 Obersch?na, USt-Id: DE253710583
www.tsht.de, info at tsht.de, Fax +49 3731 74200, Mobil: 0172 8790 741
From: Holm
Tiffe
Anyway, thanks for the schematics
Eh, de nada.
I have the board running again. The fix was
simple, the xtal was bad.
You're lucky it was something so simple! (Although we've seen this kind
of thing before - I had that 11/23 with a bad crystal.)
I've got three dead 11/73 boards (from someone else), but none of them are
that easy. Different symptoms on all three, but I suspect the State Sequencer
gate array on all three. On one, at least, the ILOE latch control signal from
that gate array is sitting at 2V (which I seem to recall is characteristic of
a TTL input that's not being driven).
Maybe it's just some corrosion, and re-seating the gate array (if I can work
out how to unseat it - don't have the extraction tool) will fix it.
Otherwise, I'm SOL. At least the J11 there are spares for - that gate array
is surely umobtainium.
Noel
3393
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3393
days old
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