1176 Rev A "Blue Stripe" Volt Issues

Hi guys,

I just mounted my 1776 blue stripe but when I turned it on, the last resistance (R32) began to smoke

My DMM write 30 V through the R32 .....

somebody can help me ?

Is it the 39 ohms resistor in the emitter leg of the 2N3053 (In series with the transformer winding)?
This would mean the 2N3053 is (almost) fully conducting.
Try to remove the 2N3707 (Q5) and see what happens.
Maybe the voltage on the base of the 2N3707 (Q5) is too high?

yes exactly, that's the 39 ohms one .....
I will try to change the Q5 and we,ll tell you.
Thanks for the answer

ok,

I removed the Q5 = 12 v in the R32
I soldered another 2n3708 in the Q5 = still 12 v

PS: there is 30 v at the black/white wire

Another precision, in the Q5 I measure:

23V in a pin
27v in an other
30v in the last one

Last measure to give you an advice:

At the big orange C10, I have 15 V at a pin and 30 V at the other

I would check the orientation of CR1 first.
You should measure something like 0.7 V over this diode.
As far as I calculate, you should have something between 3.5 and 4 V. at the junction of C10 and the base of  Q5.
Maybe you should also check C10 (Leak current)

CR1 is well oriented, 660 through it, but 22,87 V between C10 and Q5
I really don't know what to do now

Well, Q5 is an emitter follower, so it does not present a significant load at the node R29/R30/C10.
Let's ignore the DC resistance of the transformer winding in the collector of Q6 for a moment.
The voltage drop over CR1 is 0.7 V, so there is 29,3 V over R29+R30.
R29=1.2M, R30=150K.
This gives a voltage of (150/1350) * 29.3V = 3.25 V.
Add the diode voltage of 0.7 Volts (CR1) and you should have +4 V on the base of Q5.
The base-emitter junctions of Q5 and Q6 each drop 0.7 V, so this would mean 4 - 1.4 = 2.6 V on the emitter of Q6.
(Or a value close to this.)
The only reason for a higher voltage on the base of Q5 could be:

- Diode CR1 reversed or defective
- Incorrect values for R29 and/or R30
- A leaky, shorted or reversed C10
- A defective Q5

<hum

<before I check this, is that ok I have 30V in the black/red wire? (not attached to the pcb)?

Maybe you should post a picture of the (schematic of the) transformer and the wire colors.
One winding is between +30 V and the collector or Q6, the voltage here should be 30 V.
A second winding is between the emitter of Q6 and the 39 ohms resistor, voltage should be a couple of (approx. +4) volts.
The third winding (feedback) is connected to ground, so 0V. DC here.
The other winding(s) are 'floating', so no DC should be measured here.
Maybe you miswired the transformer, so that one winding is connected between +30 V and the 39 ohms resistor?
(Just guessing!!!)

ok, I have just change the Q6 with a new one ....... That WORK !!!!!!

Thanks a lot for your advices !!