On Tue, Oct 26, 2021 at 01:49 AM, Richard Merifield wrote:
Can someone confirm that the voltages on the schematic are DC voltages ? At the base of R27/R28 I see about 290V DC and not 215V as per the schematic ? I Also do not see a 30V drop across L6 (245V to 215V), in fact I see about a 6V increase. Also the resistance across L6 measures 226 Ohms which seems ok ??
Yes, those are all DC voltages.
First, are you SURE that the manual you are using is correct for YOUR 200CD. Check the serial prefix on the serial number plate and compare it to what's listed on the title page of your manual. If they don't match, the voltages may not apply.
If you don't have much current draw from the rest of the circuit, it's conceivable that reduced ripple in C13B&C, compared to C13A, might make the averaged DC measure higher across C13B&C. You could compare how much ripple you have across C13A and C13B&C; just switch your DVM to AC and measure across each one. To start, I'd measure directly across each of those caps, rather than from ground, and check R40, to make sure it's still 10 kOhms. It's odd that HP did not ground the neg side of C13, and I'm sure they did it for a good reason, but it's possible that R40 got messed up by the shorted 5AR4..
