Only right channel working after speedball mod. [resolved]

[sini]

So I just built my crack and it worked great. The next day I went to upgrade the speedball kit. I got it all assembled, but only the right channel worked. The left channel emitted some noise but was very quiet. The resistors are correct, and the solder points look good, and all of the LED's on all of the speedball boards are lit. What components should I be looking at if it's only affecting the left channel and only the speedball?

I have since reverted the mod to verify that the issue was related to the speedball (and its working fine sans speedball). I did not record the voltages when I checked, but a number of them were high by around 30-50... but none of the ones that should have been zero were non-zero. I visually inspected all of my solder points on the PCB's after disassembly and it looks clean. When removing the speedball all of the attached wires were quite solidly attached.

I appreciate any help!

[Strikkflypilot]

The voltages are supposed to be within the 10-15% margin of error as per manual.
On the speedball boards, make sure You have the right transistors in the right places, same with the resistors. Make sure the LEDs are oriented the right way.  On the big board, the center pin of the transistors are harder to solder right as the heat sink draws heat.
Check all solder joints for conduction before You reinstall the speedball.

Good luck.

[Paul Birkeland]

I did not record the voltages when I checked, but a number of them were high by around 30-50... but none of the ones that should have been zero were non-zero.

You'll have to put the Speedball back in and record the voltages, then post them here.

[sini]

I am about to reapply the speedball mod and collect voltage information. I retouched all my solder points on my speedball boards. I've taken snapshots of the boards prior to installation here: imgur.com/a/m5feZ -- I'll update again in an hour or so once I've got my iron fired up and it reinstalled and voltages measured.

My voltages pre-speedball are (for reference... they're on the high end of the 15% margin.)
1: 91.6
2: 190.3
3: 0
4: 190.3
5: 96.3
6: 0
7: 120
8: 0
9: 122.7
10: 0
11: 0
12: 0
13: 190
14: 0
15: 214
20: 0
21: 239

A1: 95
A2: 0
A3: 2
A4: 0
A5: 0
A6: 91
A7: 0
A8: 2
A9: 0

B1: 91
B2: 191
B3: 121
B4: 96
B5: 192
B6: 124
B7: 0
B8: 0

[sini]

Alright, got it reinstalled with all fresh solder joints and I'm still only getting signal from the right channel.

1: 89
2: 225
3: 0
4: 225
5: 94
6: 0
7: 133
8: 0
9: 202 (should be 100... this might be important)
10: 0
11: 0
12: 0 (My ground pin)
13: 222
14: 0
15: 237
20: 0
21: 250

I've attached a photo of the circuit. All the leds are lit on the boards, etc.

[Paul Birkeland]

Just out of curiosity, what do you see at terminal 9 with the 6080 not plugged in?

I can't ever recall an issue where the voltage at 7 or 9 went to full B+ after the installation of the Speedball. 

I can tell you, however, that you really need to remount the power transformer as indicated in the manual before doing much more troubleshooting.

-PB

[sini]

Can you clarify in regards to mounting the transformer? I just skimmed the manual and am not seeing anything thats inconsistent. I will check the voltages without the tube when I get home from work and report back.

[Paul Birkeland]

Can you clarify in regards to mounting the transformer? I just skimmed the manual and am not seeing anything thats inconsistent. I will check the voltages without the tube when I get home from work and report back.

See the second to last photo on the bottom of page 14.

[sini]

Oh. I might have installed it on the other side of the plate. That's going to be fun to move. Is there any chance that it's related to my actual issue, or is it just a safety thing?

Thanks by the way. I really appreciate the feedback.

[Paul Birkeland]

Oh. I might have installed it on the other side of the plate. That's going to be fun to move. Is there any chance that it's related to my actual issue, or is it just a safety thing?

Potentially it's both.  I've seen some very mysterious problems resolve themselves by mending problems that would be similar to the mounting situation that you have.

You're right, it's not particularly fun to fix.  Remounting power transformers is something that I end up doing on many of the repairs that come in.

-PB

[sini]

It wasn't actually that bad to move it.

Issue is still present. Voltage without tube in is:
7: 2
9: 175

[Deluk]

Can you be more specific as to what is wrong with transformer mounting in the picture? I had previously checked it against other Crack pictures and to me it also looks OK compared to the manual. Maybe I should be using a white stick.

Haven't started my build yet........... 

[Paul Birkeland]

Issue is still present. Voltage without tube in is:
7: 2
9: 175

Can you remove the red wire going to B+ from terminal 2 (easiest to do at the board), then recheck?

This is pretty unusual, with no tube in, there is no device drawing current, and the voltage at the output of the big C4S board should be right around 0.  There is something amiss with the front half of your C4S board that is causing the output to rise to B+ (and B+ is just barely present in the circuit built out on the board)

-PB

[sini]

Sure, Deluk. I placed the black fiber washers on the wrong side of the plate, so the legs on the mounting board were directly mounted to the plate.

[sini]

PB,
I've removed the wire. 9 still read around 130 but was slowly dimishing. I discharged the capacitor and it slowly climbed to but seems to have stopped at 9.5