dude, where did my power go?

[Stalemate]

Hi,
I've assembled the stereomour II kit, following the excellent instructions provided.

All my resistance tests are a-ok, but when I do the power tests, I get very low values, so low that I was wondering if my multimeter is acting up, but control tests show expected results, so I'm a bit lost here.

I've checked the transformator and gets the expected results from "secondary power check", I've checked the wiring, but the first check comes out at 2 VDC, while the expected result is 360something.

how do I troubleshoot this? I don't dare connecting it to anything, since as far as I know, there are 358 unaccounted Volts in there somewhere...

I'm a newbie, so be nice...

[Stalemate]

Hm, so after doing a quick "RTFM" on what to look for, I turned my attention to the C4S-board. I measured the transistors, and got these measurements on the "bipolar" - 1-3 ok, 1-2 null, 2-3 ok, 3-1 ok, while the other didn't give any measurements on any combination - so is this consistent with what I describe?

oh, and the leds are dark.

any help appreciated!

[kgoss]

Do a complete voltage check and post any terminals that are off by more than 10%. PB or someone else at Bottlehead will help you resolve the problem. But they need the voltages that are off plus the terminal numbers to troubleshoot.

[Stalemate]

Thanks for the advice!
I managed to break one of the mje-transistors when I was measuring its function, so I need to order some new ones

I'll be back!

v

[Stalemate]

I rebuilt the C4S and measured the function of the transistors ok, I also doublechecked the solders, and everything seems fine.

I then proceeded to check my solders, and replumed where I saw it necessarry. All the resistance checks are ok, so I plug in the tubes and power, and get the following:

1: 2VDC
2: 2VDC
3-18 : 0 VDC
19: 2VDC
20: 2VDC

The rest are dead, 0 VDC
I rechecked the wiring on the OT and PT (connectivity + config) ok

The tubes light up, I'd say a bit weak, but I haven't seen an functioning amp,so I couldn't say whether it's within the norm.

please advise..

best regards
Vegar

[Paul Birkeland]

Perform the power transformer voltage measurement for the 160V terminals and let us know what AC voltage you get there.

-PB

[Stalemate]

Thanks Paul,

I'm actually not able to measure any voltage over those terminals.

I've double checked my configuration, I have 236VAC in the mains, (which I'm able to measure on terminals 2-4)  so I configured it by connecting terminal 1 to 6, I've checked my soldering for connectivity, and it's ok.

what more tests can I do?

br
Vegar

[edit]
When I short out the 160V (19-20), the fuse blows, which should mean there is something touching something else in there.

[/edit]

[Doc B.]

You really don't want to test the transformer by shorting out the high voltage secondary. That can damage it. I suggest going back to the power transformer secondary voltage tests and check all of them - 19 and 20, 15 and 9, 14 and 11.

[Stalemate]

So I did - and there is no power there. Shorting out the 19 and 20 was an accident, I was clumsy and managed to touch both poles with the multimeter.

v

[Doc B.]

Did you test the other secondaries, 3.3V and 6.3V?

[Stalemate]

Hi,
Yes I did, The measurements are neglible, the multimeter a very low current (~0.2 mV) on both.

So to summarize, I'm able to trace the 236 VAC from the wall, via the 46-48 mounts to pin 2 and 4.
I've connected pin 1 to pin 6 to configure the transformer for that current. I'm able to measure 0 ohms on all my connections, meaning the solder and cable is ok, but none of the secondaries gives any reading, other than flutter on the meter. What am I missing here?

thanks
V

[Paul Birkeland]

Post a photo of your black and red power supply jumpers that attach from the terminal strip to the set of 6 lugs.
-PB

[Stalemate]

Hi,
Here you go

v

[Deluk]

Shouldn't the black wires be soldered to the earth tag at the bottom of the first picture?

[Stalemate]

Shouldn't the black wires be soldered to the earth tag at the bottom of the first picture?

You're right, so I did, but to no avail...

br
V