Re: [Tek 485] No intensity control


Ozan
 

I see ~42mV at collector of Q1548, no dot on screen in XY Mode.
Base of Q1544 is at ~1V, HFE measured with a TC1 tester : 214
Look OK.

CR1539 is ok : ~.6V and 0L
Looks OK.

R1536 measured in circuit gives : 300kohm and 100kohm (when inverting the test
leads of DMM).
This is a very large resistor, you won't be able to get a good read without removing a leg. I recommend checking C1537 first, see below.

I just noticed C1537 is an electrolytic cap although its value is small. It could have developed a small leakage. If you remove it do you see any difference?
Ozan

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