Speed ball upgrade - Right headphone not working [solved]

besley1600 · 1304

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Offline besley1600

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Hey everyone!
After having correctly built the standard crack, I decided to upgrade to the speedball. I am having a problem where the right headphone has no output other than a deep hum
The A8 LED is not lighting up and I am having a few voltage issues.

Voltages:
1: 0
2: 179.0
3: 0
4: 181.6
5: 73.9
6: 0
7: 56.1
8: 0
9: 105.8
10: 0
11: 0
12: 0
13: 177.9
14: 0
15: 199.0
16: 0
17: 0
18: 77.5
19: 76.6
20: 0
21: 219
22: 0
A1: 74.5
A2: 0
A3: 1.6
A4: 0
A5: 0
A6: 0
A7: 0
A8: 0.9
A9: 0
B1: 0
B2: 177.2
B3: 57.2
B4: 74.0
B5: 181.7
B6: 106.5
B7: 0
B8: 0

All LEDs but A8 are lit. I cannot see why I am getting this issue. Please help! Thank you 
« Last Edit: January 06, 2015, 10:40:00 AM by Caucasian Blackplate »



Offline Paul Birkeland

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Reply #1 on: January 05, 2015, 06:59:14 AM
The first thing to do is to check that you haven't swapped the 2N2907 and 2N2222A transistors. 

Next, the 0V on terminal 1 suggests that perhaps the center leg of the MJE-350 on the small board feeding that terminal is not properly soldered.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline besley1600

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Reply #2 on: January 05, 2015, 07:57:23 AM
I re-soldered the center leg of the MJE-350 and it now functions correctly!
Thank you for the help