More RLV12/RL02 problems (faults on Write)
charlesmorris at direcway.com
Thu Jan 5 08:57:04 CST 2006
On Wed, 04 Jan 2006 23:15:48 -0600 (CST), you wrote:
>It sounds very much like he could have blown something on the controller the
>first time when he wired it wrong, and said it got "hot".
That was only referring to the transistor that drives the POK
signal. It survived. I had also found that the "upside-down and
backwards" hookup places two 75113 drivers in contention - but
they are not fried either.
>Either that or, I'd still blame the cable. I haven't known qbus cards to
>just go bad like that.
Unlikely given that all read tests pass and the system boots...
and the Write Data and Write Gate signals are making it to the
logic board in the RL02, by direct measurement.
I missed the fact that the error code returned by the toggle-in
program (102210) actually has WDE (15) as well as WGE (10) set. I
am not sure which came first (i.e. the write data error resulted
from the Fault/head withdrawal after the write gate error, or vice
But the problem could also be on the drive's R/W board. There is
some logic there that can cause a WDE. I'm not sure what fault
happens if there is a bad steering diode or write current source.
More as I investigate... I may have to fix the faulty p/s on my
Tek 7403 so I can plug in the logic analyzer! That will tell me
for sure which line is first.
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