SB-610 problems

[Robert Myers]

My SB-610 just stated to smoke.  It had not been in use for several years,
but had been cleaned and working fine for a few weeks.  When I opened it I
saw the 330K resistor between lugs 2 and 4 of terminal strip 'B' (underneath
unit) was smoking.  The manual says that this could mean:

1. D5 or D6 (both of them are selenium diodes) have become defective; or

2. C606 or C607 defective; or 

3. a transformer winding is shorted.