[UK-CONTEST] FT1000Mp Mk V display

[Dave Sergeant]

On 3 Jan 2006 at 20:03, G4FNL wrote:

> Dick et al
> 
> This link may help if you need a better explanation and possible fix (the
> problem also occurs on the standard FT1000MP:
> http://mailman.qth.net/pipermail/1000mp/2002-August/003516.html
> 
Reading this posting it seems there are probably two issues:

1. Failure of the thermal fuse - probably because it is underrated 
for the current rather than it exceeding its trigger temperature.
2. Failure of the dc/dc converter to produce the required volts for 
the display. My gut feeling would be a duff electrolytic capacitor 
inside this module, which would explain why it comes on eventually. 
These displays will require two voltages - around -30Vish for the 
cathode supplies and a few volts ac or dc to drive the heaters. If 
the heaters are dc there is a fair chance that the smoothing cap for 
that supply is duff.

Not familiar with 1000MPs at all but these sorts of problems are 
every day ones in VCRs. First suspect in any sort of failure like 
this is electrolytics, especially if crammed in small places against 
hot running transisitors. They are by far the most unreliable 
components in todays electronics.

73 Dave G3YMC

http://www.davesergeant.com