Hello, all-- now I'm really perplexed. As I said before, My Cornet2 has no signal output ifrom the right channel with a known-functional turntable feeding it music signal, despite a flawless left channel output.
However, As soon as I touch my voltmeter to any of the PCB test points, like R107 which has "365 VDC" printed next to it, and really almost any resistor that is part of the right channel circuitry, the amplified music signal in the previously silent right channel suddenly comes in, as loud, undistorted, and sweet-sounding as the left channel. I also get the right channel to come in by touching the voltmeter's positive test probe to the screw that attaches Q200R to its heatsink (I'm using a TIP50 so it is not encased in plastic to isolate it electrically from the heatsink)
But now I have found a really troubling new problem-- HIGH AC voltage EVERYWHERE.
At the various test points on the PCB, like where I should have 365VDC at R107, the DC is 30 volts HIGH, but I just discovered that EVERYWHERE in the preamp I have insanely high AC voltages on these DC test points (and elsewhere)...At resistor 107, where I should have 365 VDC, I have about 385 VDC... and more than 600 volts AC! Is this POSSIBLE? Or is my voltmeter deceiving me? The meter was inexpensive, but it measures all the voltages in my Audio Research preamp at or near spec...
It places 340 volts AC on my 300VDC RIAA caps, so I am afraid to even do much troubleshooting.... is this EMI/RF amplification gone mad? (sorry if that is a silly guess, but???)
Any thoughts?
