Speedball big board issue [resolved]

louis.jeck · 1161

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Offline louis.jeck

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on: January 11, 2018, 10:00:21 PM
Hi everyone !
I came across a problem while assembling the Speedball upgrade.
Everything went great until I added the big board, I lost the right channel.
I measure 200v on OB, the corresponding capacitor (7U) does not discharge when the device is turned off (big spark when shorting it), the LEDs light up instantly while the other ones light up normally as the tube warms up. Everything else seems to be fine. Crack worked fine before the speedball upgrade, and all soldered connections look solid.

Any ideas or further tests I should do ?

Thanks,
Louis.
« Last Edit: January 14, 2018, 07:08:59 AM by Caucasian Blackplate »



Offline Paul Birkeland

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Reply #1 on: January 12, 2018, 04:01:34 AM
I would check the connections under the board, paying special attention to any solder bridges that are connecting two adjacent terminals on a transistor by accident.  There may also simply be a joint on the board that isn't soldered, or white wire leaving that side of the board may not be well connected or may be broken.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline louis.jeck

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Reply #2 on: January 13, 2018, 10:47:26 AM
I did continuity checks and found a bad joint, voltages now read as they should are are pretty much symmetrical. Still had no sound on the right channel. Unplugging it of a while and re plugging it made it work !
Thanks for the help :)



Offline Paul Birkeland

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Reply #3 on: January 14, 2018, 07:08:47 AM
You may still have another solder joint or two that are loose.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man