Problems after speedball(Solved)

[Strikkflypilot]

Hi.

I guess You didn't see my edit of the last post or it is Sunday.
I now went ahead and checked all solders on the PCBs. They seem solid.

Being no expert I cannot check the transistors properly but the NPNs have high resistance to the emitters and collectors although not identical and the PNPs have high measurable resistances.

I did find a diode that has no voltage drop, maybe related to the spark from the collector of the adjacent TIP50 during my conduction test after voltage tests(after unplugging of course)

I also noticed that the diodes have different voltage drops. Some around 0,75v that don't light up and some at around 1,5v that light up.

Anyway.
The final culprit seems to me to be just one small diode.

[Paul Birkeland]

Your meter's ability measure to the LED voltage drop while they are installed on the PC board is not an indicator of how they function.  For most meters I own, only one of the LED's can be measured.  A few meters will not be able to measure either, and some will be able to measure both.

If the LED isn't in backwards and hasn't visibly exploded, then you can assume that it's working.

[Strikkflypilot]

Thanks for the reply

It just fitted the picture, being one of the two LEDS that didn't light up.
Putting the PCBs back into the curcuit like they are now would only put me back with funky numbers as I haven't changed anything...

Nothing else I could do to troubleshoot before reinstall?

[Paul Birkeland]

I'd post a photo of the top and bottom of the big PC board, we may be able to spot something that you haven't spotted yet.

[Strikkflypilot]

Appreciate Your help.

Here are the pics. You will notice that the emitter leg of one of the 2N2s hardly has solder, but it is on the end where the LEDs did light up and and conduction test is good from that leg to the leg of the small resistor it is connected to on the PCB. That or anything else strike You as rotten?

[Paul Birkeland]

I would say that there is a little too much solder on the underside of that PC board.  Some of it may have wicked up under those 2N2222A's and shorted the case to other legs. 

[Strikkflypilot]

So I ve tried again.
Enjoyed the stock crack immensely for two days or so.

Now I have resoldered ALL the speedball legs and ALL the
terminals.

Like last time, the two leds on the bigboard close to the PS
wont light up.

Before I soldered the PCBs I checked all the conducting and AGAIN,
only the one diode closest to the TIP50 on the side that doesnt
Light up measures weird.
I couldnt find a voltage drop or measurable resistanc over
it, no matter the polarity of the testing

I would already have ordered a replacement but cant find a replacement
6000. 

Do You think something else is wrong?

1. Drop from 65v
2. Drop from 100v
3. 16mV
4. Drop from 100v
5. 75,92v
6. 16mV
7. Drop from 65v
8. 16mv
9. 77,6V
10. 16mV
11. 16mv
12. 0v
13. Drop from 100v
14. 0v
15. 144v
20. 0v
21. 193,1v.

Am I missing something?

[Paul Birkeland]

Can you try rotating the big pc board 180 degrees and installing it that way.

If so, does the same side stay dark?

If the dark side also rotates with the board, then I would replace both the transistors on that side, using as little solder on the 2N2222A's as is possible. 

If the dark side remains to the rear of the amp, then there is a wiring issue with the installation that we can troubleshoot at that time.

[Strikkflypilot]

And 180 degrees

[Paul Birkeland]

Well done.

Yes, that is fried transistor(s).

-PB

[Strikkflypilot]

I thank You Sir.
I did have a spark from the middle leg of That
particular TIP50 during conduction test. At that point the
2N2s had bad solders.
My theory is that the one LED I keep writing about bought it
since, well, Ive gone on and on about it enough.

So I replace the TIP50, 2N2222A and, indulge me , the dead LED
on the dark half of the bigboard, yes?

Would You be so kind to mail me their datasheets so I order the right ones?

Yours truly
  Strikkflypilot

[Paul Birkeland]

A blown LED will literally explode. Yours is OK.

Any old tip50 will work. The 2N2222A should be in a metal can, but otherwise the variations aren't super important.

PB

[Strikkflypilot]

I have ordered two of a kind from different manufacturers.
Would You have changed transistors on both sides or just the one
currently without current? Just so they are as similar as possible?

Lots of people go on about how material changes makes all the difference
in sound quality.

[Paul Birkeland]

I would focus on getting the dark side to work first. 

-PB

[Strikkflypilot]

Thanks.
Will do as soon as they are delivered.