Hi Jon, I can hear a light crackle but not a whine.
Are you referring to Q202? The centre pin is 11v, the other two are at 0v. Thanks, Aaron Jon Elson writes: > On 04/29/2017 08:34 AM, Aaron Jackson via cctalk wrote: >> The heater and control pins appear to be giving sensible voltages. The >> logic of the board is fine, I can type on the terminals keyboard and I >> get the correct characters on the other end of the serial cable. The PSU >> is putting out 31v which seems fine? >> >> I'm used to discharging the tube before fixing things inside CRTs >> (usually I only attempt to fix simple things like a broken toggle >> switch), but I have not managed to get a spark off this monitor. The >> tube doesn't seem to get charged up at all. > If everything is working, even a small monochrome monitor > should give a bit of a crackle (might have to listen closely > in a quiet place) and you should be able to feel the > electrostatic field on the hairs on the back of your hand > for a few seconds after powering on. >> I've measured the >> capacitance of nearly all caps and they seem fine, diodes seem to be >> working fine. Does this mean it is most likely the flyback transformer? >> > Since it doesn't smoke, I'm thinking the horizontal sweep > transistor may have gone out. It may have shorted, which > then may have burned up the primary winding in the flyback > (if left on long enough). I'd check that transistor for a > short, and then you can trace a few traces to identify the > primary terminals on the flyback and see if they are an open > circuit. > > Jon
