So a follow up for those who are tracking this Alpha 87A issue.
Pulled HVPS PCB to gain access to the LVPS Fuse. Fuse Checks out good.
While the HVPS PCB was out, was able to unseat and reseat the hard to reach
LVPS Connections.
Put it all back together and attempted to start the Amp, still receiving the
Fault 37.
During this and all previous testing, crossed the Hard Fault Threshold Twice
causing a Fault 99. Cleared it both times, still getting Fault 37; no stuck
bits here.
Verified +36Vdc, currently need to verify the 5, 10, 15, 20Vdc output when I
get the next opportunity to do so.
Thank you,
Mike
W5CUL
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Mike
Sent: Sunday, January 20, 2019 9:18 AM
To: amps@contesting.com
Subject: [Amps] Alpha 87A Fault 37 and No LEDs
So today I fired up my Alpha 87A for the first time in several months. It
powered up for about 30 seconds then shut down with a Fault 37. The fault
code basically indicates the Bandswitch is not moving. But what I find
peculiar is that none of the LEDs come on either. This would lead me to
believe something more than just the Bandswitch issue. So here are the
things I have done so far:
Manually moved the Bandswitch, returning it back to its original position.
The thought here is a stuck motor that needs a little assistance to get past
a sticking point. Got the same Fault.
Pulled the Front Panel and unseated reseated all connections on the Motor
Driver Board. Got the same Fault.
Went into the Low Voltage Board and unseated reseated all connections. Got
the same Fault
Pulled all the connections from the Transformer and reseated them. Got the
same Fault
Pulled the Tubes and attempted to fire up the Amp. Got the same Fault
Thinking that there is difference between turning the Amp on using the
Rocker Switch versus a Remote Command, tried that as well. Got the same
Fault.
At least the fault is consistent, but it is those LEDs not coming on that
really has me wondering. I would have thought at least the Wait and or
maybe even the Fault LED would have lit, however briefly, but nothing.
So here is the ask, anyone out there with an Alpha 87A ever experience this,
or maybe know of someone who has, or has knowledge of such a Fault? I have
searched the Web high and low and have not seen any buzz about this fault at
all or even any similar description of such events. So I am kind of
shooting blindly in the dark here, scratching my head wondering what else I
can possibly do to narrow this down to the evil culprit that is causing
this. Yes, I do know electronic Gremlins exist, but I did not see any
evidence of such as they usually leave little solder balls laying around.
Thank you,
Mike
W5CUL
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