The second squeeled upon switch on and continued at a low level , again replacement of 4 capacitors and a couple of diodes and mod's and the board runs perfectly.
the third was dead, all the voltage rails were pulsating , this turned out to be a short circuit 3v3 receifier diode and close examination of the 1,200Uf smoothing capactor confirmed that the capa had failed causing the diode to fail. replacment of the diodes and caps in both the 3v3 and 5v5 volt lines recetified all problems.
I fear alot of problems with these units stem from the fact no body was willing to explain what the problems are. the only other problm i am aware of with these units is a mod to stop intermitant picture loss to blue screen and intermitant power supply shut down. The cure is to change a surface mounted restister from 1K to 1.5K
These problems are consistant with other makes of satellite equipment using simliar SMP's.