[Premium-Rx] WJ-8711A front panel problem

[rtm at lcs.mit.edu]

Thank you for the ideas!

I tried improving the ground connection, and fiddling with and
deoxit-ing the power and ribbon cables, but so far to no avail. The
power supply voltages all look good, as delivered to the boards.
Resistance between grounds on different boards is <= 0.4 ohms.

Robert

> Date: Tue, 28 Aug 2012 12:55:14 -0400
> From: rtm at lcs.mit.edu
> Subject: [Premium-Rx] WJ-8711A front panel problem
> To: premium-rx at mailman.qth.net
> Message-ID: <52714.1346172914 at nephron.lcs.mit.edu>
> 
> I have a WJ-8711A that worked well until a week ago. But now something
> has gone wrong with the front panel. First, the IF BW display is usually
> blank, though it flickers when I change bandwidths. Worse, the entire
> front panel often (but not always) flickers on and off for about a
> second when I change IF BW, mode, special function, remote, &c. It is as
> if the front panel microprocessor were rebooting, or as if the main
> control processor and front panel processor briefly lost sync.
> Occasionally after power-cycling the radio will work perfectly for a few
> minutes, then exhibit these problems again. The underlying radio seems
> fine: nothing odd is audible even when the front panel is being flakey.
> Tuning and keypad frequency entry work. The BITE passes. Reset doesn't
> help. Firmware version 04.01.04.
> 
> I'd be grateful for any ideas!
> 
> Thank you,
> Robert