It's got issues, and I'm not sure I understand how this circuit is really supposed to work. It looks to me like all the transistors are biased backwards!!
I would much appreciate it if you could have a peek and give any advice or direction, I'm beating my head against the wall on this one.
Circuit fragment is attached, with measured voltages marked in blue.
Thanks in advance,
Dare
http://derekyates.net/5103N_schematic.pdf
Or if that's not enough for some reason, the whole PS circuit is here on page 55 of the manual.
http://derekyates.net/Tek 5103N_v6.pdf
So far I have tried the following:
1) Replace Q850 with new 2N3904 (after I did I realized the old one was OK)
2) Replace Q845 with new 2N222A (also no change, old transistor measures fine)
3) Lift and check R858 and R859 for drift, both are at 6.03K-6.035k on my meter
4) Checked VR850, CR841, and each of the capacitors to make sure they function normally
5) Measure each voltage shown in blue, to try to formulate a plan for what's going on there. I'm still stumped though!
I would much appreciate it if you could have a peek and give any advice or direction, I'm beating my head against the wall on this one.
Circuit fragment is attached, with measured voltages marked in blue.
Thanks in advance,
Dare
http://derekyates.net/5103N_schematic.pdf
Or if that's not enough for some reason, the whole PS circuit is here on page 55 of the manual.
http://derekyates.net/Tek 5103N_v6.pdf
So far I have tried the following:
1) Replace Q850 with new 2N3904 (after I did I realized the old one was OK)
2) Replace Q845 with new 2N222A (also no change, old transistor measures fine)
3) Lift and check R858 and R859 for drift, both are at 6.03K-6.035k on my meter
4) Checked VR850, CR841, and each of the capacitors to make sure they function normally
5) Measure each voltage shown in blue, to try to formulate a plan for what's going on there. I'm still stumped though!
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