Quote:
Originally Posted by RobertF
I am only getting 160v at the rectifier (Mazda UU9) . If I remove the rectifier the voltage goes up to 200v. The schematic says it should be 240v.
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Hi Robert, where are you measuring the voltage, and are you quoting a dc or ac measurement? UU9 pins 2 and 6 are the anodes so they should each measure 240v ac with the negative meter probe connected to chassis. That should not change with the rectifier in or out unless for example the rectifier has an internal short or the HT reservoir capacitor has gone very leaky and the rectifier is drawing a massive current. The cathode pin 7 should be measuring anything from 280v dc downwards depending on the condition of the rectifier valve. I doubt that the transformer is at fault but if you clarify the measurements in the light of the above it would be easier to diagnose the fault. The most common suspect is that the rectifier has gone low emission and its dc output is dropping when on-load. Cheers, Jerry