[Premium-Rx] WTD: Cubic 3280/3250 display and a repair story

[VK3XYZ]

Hi all,
I have a CDR3280 and I'd be interested in locating a replacement display. 
The one I have has some burn in which causes light and dark patches over the 
display area.

The story - which is a new one for me.
After recently using the CDR3280 (after a post here) the receiver became 
intermittent in all aspects of its operation and the usual burnt electronics 
smell was emitted. After disassembly of the receiver I turned it on and 
watched for tell tale smoke. I noted 'light' being emitted from within the 
power supply and its fault LED intermittently turning on.

After disassembly of the power supply I found that the HV rail to the 
switching transformer/inductor had been arcing to ground near C10, where the 
HV line and ground are at their closest. It doesn't appear to be HV creep, I 
doubt the voltage is that high. The capacitor is glued to the board and the 
placement of the glue straddled the HV and ground connection. Either a) 
their was contamination under the glue when it set, b) over time moisture 
and dust has built up on the glue and provided a leakage path or c) the glue 
has become somewhat conductive over time. C10 doesn't appear to have been 
leaking so it's not the cause. I expect (a) as the damage was underneath the 
straddled glue and insulation testing of the glue on the removed C10 found 
no leakage even with a 1kV setting. I've also not seen this sort of thing 
happen with old dirty dusty computer power supplies which are comparable.

The result has been a small volume of PCB material has been turned to carbon 
and this has provided a low resistance path at times, emitting light and 
smell as it burnt.  Ended up with a divot just over 1/2 the depth of the PCB 
having being eaten away. Given the size and ratings of this power supply I 
assume this has been happening for quite some time, most likely before I 
became the owner. Cleaned out the carbon deposits, backfilled with a neutral 
cure silicon and all is well again (no glue on C10).

Cheers
Greg