Re: FG502 doesn't start at some specific settings


Ozan
 

I don't have this equipment but here is my feedback in addition to Mark's suggestions:

Digging around I found that the triangular generator stays in a state where is
happy (I can provide all voltages in significant points of the schematic)
Are +17V, "+17V (DCPL 1)", -17V, "-17V (DCPL 1)" on sheet <1> stable when cold (not working)?

In the happy non-working state what are the voltages (partial list is OK if you don't have them all):
1) at the gate of Q200, and collector of Q292.
2) bases of Q230A and Q230B
3) bases of Q290 and Q292
4) emitters of Q140 and Q175

In case gate circuit is acting funny: Voltage at collectors of Q325 and Q315

until it decides to start working. I'm attaching two pictures of a normal
start and the delayed one. In the second one (4018-1) note the Ch4 (blue)
baseline is at the top of the display screen.
What are the test points for the different traces?

Ozan

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