KenLayton
In Memoriam
Peter Chou UK9.2A screw terminal power supply (a.k.a. USP-9).
Symptom: appears inoperative or dead. Fuse good, capacitors good, transistors and diodes are good.
Cause: resistors R6 and/or R11 are bad (open). Unsolder one lead of each resistor to test these otherwise false readings will occur. Sometimes if one of these resistors is starting to go bad, the power supply may operate intermittently.
Cure: If either one of the above resistors are bad, replace BOTH of them. The originals are both 330K @ 1/2 watt carbon. It is suggested to upgrade these to the same value but in metal film versions instead of carbon.
Note: the "UK9.2A" model number is silkscreened on the foil side of the circuit board.
Symptom: appears inoperative or dead. Fuse good, capacitors good, transistors and diodes are good.
Cause: resistors R6 and/or R11 are bad (open). Unsolder one lead of each resistor to test these otherwise false readings will occur. Sometimes if one of these resistors is starting to go bad, the power supply may operate intermittently.
Cure: If either one of the above resistors are bad, replace BOTH of them. The originals are both 330K @ 1/2 watt carbon. It is suggested to upgrade these to the same value but in metal film versions instead of carbon.
Note: the "UK9.2A" model number is silkscreened on the foil side of the circuit board.
Last edited:
