Ok. There is a short to GND somewhere on the -60V supply line.
This will take some time find.
Let me take a look at where J208, J209, J210 are connected in order to find some test points to make resistance measurements.

 

hm, ok.. but how did it happen.....
I believe it must be a component failing, not an accidental short, because when it happened, it stood with power on for several minutes when i was measuring points... and suddenly i heard a humming sound and i thought what's happening now... and right after R513 went up in smoke...

 

With POWER OFF and unplugged, we will do some resistance checks.

At this point I assume C425 and C426 have been removed. Make sure that there are no shorts at the C425 and C426 solder pads.
Also R506 has been removed.

Measure resistance between J401 and J402. Measure both ways (i.e. leads reversed).
If you get a low resistance (under 10Ω) proceed with the following.

Cut J219 in the middle with a side cutter. Separate the two cut wires so that they are apart and not touching.
Measure resistance between J401 and left side of J219, both ways.
Measure resistance between J401 and right side of J219, both ways.

 

With POWER OFF and unplugged, we will do some resistance checks.
At this point I assume C425 and C426 have been removed. Make sure that there are no shorts at the C425 and C426 solder pads.
Also R506 has been removed.

Measure resistance between J401 and J402. Measure both ways (i.e. leads reversed).
If you get a low resistance (under 10Ω) proceed with the following.

C425 and C426 are removed and there is no solder issues. R506 has also been removed.

So i measure the resistance between J401 and J402..

With the red wire to J401 the resistance is increasing very rapidly, and stops on the value you can see in my picture.
If i do measure the other way with black wire at J401 the resistance just increase until it gets out of range... like open circuit

So i did not proceed with the other you described...

 

Ok.

Go ahead and cut J219.

 

So i cut J219.

Let's use right and left in in your picture, my picture here will be opposit.

When i put red wire to J401 and black to the left leg of J219 in your picture i got 512Ω
The three other combinations just increases till it gets out of range

 

Your picture shows the BLACK probe on the RIGHT leg. Is that correct?
You measured 512Ω on the LEFT leg.
Thus the fault is in the RIGHT channel (i.e. towards the components that end in EVEN numbers).
That should narrow it down to about four transistors

Q412
Q416
Q426
Q430.

Do transistor tests on these while in-circuit, i.e. no power, don't remove the transistors.

 

Your picture shows the BLACK probe on the RIGHT leg. Is that correct?
You measured 512Ω on the LEFT leg.

You are correct, sorry for the most confusing picture.
Picture was ment just to show what i did, and did not show the measuring with 512Ω

I will check the transistors in circuit

 

Measured transistors in circuit:

Q412:
Red to B
Black to E: 876
Black to C: 855
Black to B
Red to E: 0
Red to C: 0
Red to E
Black to C: 1623
Black to E
Red to C: 0

Q416:
Red to B
Black to E: 0
Black to C: 0
Black to B
Red to E: 840
Red to C: 835
Red to E
Black to C: short
Black to E
Red to C: short

Q426
Red to B
Black to E: 0
Black to C: 1425
Black to B
Red to E: 884
Red to C: 824
Red to E
Black to C: 822
Black to E
Red to C: 762

Q430
Red to B
Black to E: 924
Black to C: 826
Black to B
Red to E: 772
Red to C: 763
Red to E
Black to C: 93
Black to E
Red to C: 93

 

In your report, some measurements are shown as "0" while some are shown as "short".
Can you clarify the difference?
By "0" do you mean "open"?
What reading shows on the meter when you report "short"?

 

In any case, remove Q430 and test out-of-circuit.

With Q430 removed, repeat the resistance measurements between J401 and J219.

Did you manage to find some more 6.8Ω ¼W resisitors?

 

In your report, some measurements are shown as "0" while some are shown as "short".
Can you clarify the difference?
By "0" do you mean "open"?
What reading shows on the meter when you report "short"?

Sorry not beeing specific enough, yes with 0 i mean open circuit, i rather might type open circuit than 0, i agree

My DMM "beeps" when the contact is good enough, i don't know exactly at which value it does, but i take that as the transistor has a short circuit...
Look at the picture, there's the value at Q416 with Red to E and black to C and it beeps.

 

In any case, remove Q430 and test out-of-circuit.
With Q430 removed, repeat the resistance measurements between J401 and J219.
Did you manage to find some more 6.8Ω ¼W resisitors?

I will do soon!
No,i did not get more 6.8Ω ¼W resistors, the local guy has not been at work, and now it's holidays until next Tuesday...

 

I will do soon!
No,i did not get more 6.8Ω ¼W resistors, the local guy has not been at work, and now it's holidays until next Tuesday...

Ok. In the meantime, after removing Q430, test Q430. Then test resistance between J401 and J219 (as previously posted in #211).

Then remove Q416 and test Q416.
Test again between J401 and J219.

 

So at first i removed Q430 and tested it:

Q430
Red to B
Black to E: open circuit
Black to C: open circuit
Black to B
Red to E: 703
Red to C: 692
Red to E
Black to C: open circuit
Black to E
Red to C: open circuit

Then i measured resistance between J401 and J219:
With black to J401 it's open circuit at both J219
With red to J401 and to the right J219 i get 534 at the 2000K setting on my DMM.. hehe.. almost open circuit or what?
With red to J401 and black to the left J219 i got 510Ω

Then i removed Q416 and checked it

Q416
Red to B
Black to E: open circuit
Black to C: open circuit
Black to B
Red to E: 802
Red to C: 798
Red to E
Black to C: short circuit (value: 4)
Black to E
Red to C: short circuit (value: 4)

Then i measured resistance between J401 and J219 again.
Readings are the same as after i removed Q430 with a little difference, i got 580 at the 2000K DDM setting, and 505Ω with black to left J219

 

Measure resistance across:

D405
D407
D406
D408

D410
D412

in both directions.

(I assume Q406 and Q408 have been removed?)

 

Measure resistance across:
(I assume Q406 and Q408 have been removed?)

Yes, Q406 and Q408 are labeled and put aside.

D405: open / 1668
D407: open / 1470

D406: open / 1671
D408: open / 1458

D410: open / 945
D412: open / 939

 

Remove IC402 (in your 8-pin socket) and measure resistance from J401 to J219.

 

Remove IC402 (in your 8-pin socket) and measure resistance from J401 to J219.

Removed IC402 from socket.

Black to J401, both J219 measured open.

Red to J401.
Left J219: 511Ω
Righ J219: Open

 

Just to be clear, we are looking for a low resistance path somewhere in the RIGHT channel from -Vs to GND..
That is a difficult task in most circumstances. The ultimate solution is rip out all components and test each one, one at a time. Of course, we want to avoid having to do that.

I will need some time to look at where the various jumpers are installed so that we can do a binary-style search.