Step #3 – Repair & replacement
a.
I suggest you replace at least C8, C9, C12 or preferably all electrolytic capacitors on the
PSU PCB with +105 C versions, but not necessarily the rectifier filter's 470 uF/200 V big
caps, if they seem OK and you can measure their value or even better, the ESR too.
b.
Replace R17 and R18 (optional) with a pair of 5W, 33ohm resistors (DigiKey p/n
45F33RE-ND). Install the new resistors on end, and do not trim the long lead…instead
coil it so that it can dissipate some of the heat from the resistor (wrap it around a drill bit
to coil it).
c.
Re-solder (with fresh solder and flux) all the cracked or “cold” solder connections on the
PCB (especially around the transformer).
d.
Remove solder splashes (and possible solder bridges) with brush carefully.
e.
Reinstall the base plate, cage and secure the unit in place in the chassis and temporarily
connect the AC cable and see if the unit now works. If it does, unplug AC cord and now
reassemble the rest
Fig 2. Thoroughly inspect the solder side of the board for cracked solder joints - the next
picture shows several bad joints.
