On Saturday, 29 July 2017 20:59:12 UTC+1, Dave M wrote:
Yes, the 1N4007 recrifiers should be good replacements. Likely to be the
only problem in your unit.

As a precaution, you should check the large transistors on the board. They
are likely to be high voltage MOSFETs, and should NOT be shorted or low
resistance from drain to source or from gate to any other terminal. Best to
take them off the board to test, since they're certain to be connected to
the low resistance transformer windings, which could lead you astray.

Cheers,
Dave M

I've been led astray by small amounts of capacitance before


NT