Yes. Get rid of C7, if you use release boards from passdiy and ZVP3310. Then fire again
Best,
nAr
Don't get too desperate. At least now PSU is turned the good way, and voltages are correct.
Unmount C7 as I said. Change leds and bipolars and see how it works. Can you get the voltages on the lowest resistors on schematic. At least it can help finding is biasing of each stage is correct or not. You'll also have to determine whether all the resistors are OK, or if one has now uncorrect value or seems damaged. last thing would be replacing jfets if one or more seem not to pass the intended current.
Best,
nAr
Unmount C7 as I said. Change leds and bipolars and see how it works. Can you get the voltages on the lowest resistors on schematic. At least it can help finding is biasing of each stage is correct or not. You'll also have to determine whether all the resistors are OK, or if one has now uncorrect value or seems damaged. last thing would be replacing jfets if one or more seem not to pass the intended current.
Best,
nAr
In that case I would also replace Q2, Q11 and R29
Can you do some measures and tell us which voltage you get in the usual places ? V+/ V-;
V on drain of Q6-Q9;
Voltage across R28 and R29.
Best,
nAr
Board 1
Q 6 , 31.2 mv
7 , 45.5 mv
8 , 32.3 mv
9 , 31.5 mv
R 28 , - 21.69
29 , - 21.69
Pad = -24.42
Board 2
Q 6 , 32.8 mv
7 , 31.6 mv
8 , 31.9 mv
9 , 32.9 mv
R 28 , -21.59
29, -21.49
Pad = - 24.33
Down to my last 250mA fuse . If I turn it off to remove ZTX 450 and ZVP 3310 . I'll blow it turning it back on ..... Why is this ? If I put a NTC before the fuse would it help ?
Rich
Q 6 , 31.2 mv
7 , 45.5 mv
8 , 32.3 mv
9 , 31.5 mv
R 28 , - 21.69
29 , - 21.69
Pad = -24.42
Board 2
Q 6 , 32.8 mv
7 , 31.6 mv
8 , 31.9 mv
9 , 32.9 mv
R 28 , -21.59
29, -21.49
Pad = - 24.33
Down to my last 250mA fuse . If I turn it off to remove ZTX 450 and ZVP 3310 . I'll blow it turning it back on ..... Why is this ? If I put a NTC before the fuse would it help ?
Rich
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Across R28 and also R29 you should have 1 volt or so. I dunno 1st stage Q6_Q9 seems fine, slightly low but maybe in relation with IDSS of the particular devices.
It seems current flows without been controlled. Could be the CCS (bipolars-leds) / jfets / mosfet of the 2nd stage all blown. I'm afraid you'll have to change all leds, bipolars jfets and mosfets of the 2nd stage before firing up again.
Best,
nAr
jfet IDSS matching / tolerance
No, bipolars are transistors ...
If they are lit normally, no; make sure they don't run like hell
Best,
nAr
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Good. No, if you use ZVP3310 and Wayne's board, C7 is to omit, causes oscilations problems in some cases.
nAr
