Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: BLACKPIPE on April 30, 2018, 10:44:20 AM
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Hello everyone!
After owning/having built the base Crack for about a year now, I finally decided to install the Speedball I purchased along with it - however, I am having some issues with continuing onto the voltage check of the big board.
As soon as I touched my probe to OB, (the first and only terminal I've attempted to test), it sparked on me and I immediately stopped and unplugged the Crack. That was on Friday, and today I finally had time to mess around with potential soldering issues - I desoldered all 4 connections to the terminals, the wires themselves which are attached to 3U/4U/7U/9U, as well as resoldered any old connections which were attached to 3/4/7/9U.
My resistance checks stated O.L. on both OB/OA again, so I attempted the voltage check just now and the spark occurred again at OB.
I have not trimmed any of the wires which are attached to the big board just yet in the case that I have to resolder/attach the wires again. Not sure if that would be enough to cause an issue, but worth mentioning.
I will upload pictures in a few as well.
Thank you for taking a look,
- Ben
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Which board are you working on? (The small one or the big one)
A spark when touching a terminal might indicate that your meter isn't set properly for measuring voltage. If you had it set to measure current, you'd get a huge spark when you touched a terminal.
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Hi CB,
I am working on the big board. I have just taken a bunch of pics with my phone cam (DSLR battery needs to be charged). I have also included a picture of the multimeter setting during volt checks - I may very well have completely chosen the wrong setting there lol.
In the pictures - OA is supposed to use a white wire to 9U however during my multiple attempted "fixes" I ran out of white, so opted to use black - just as a heads up.
Having trouble with uploading pics to the site at the moment however - but I have uploaded the pics to my Google Photos account as an album. Here is the link for that:
https://photos.app.goo.gl/l8DCOA0DTzl9C7Qb2
Thank you for your assistance!
- Ben
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The red probe of your meter is plugged into the current shunt input, not the voltage measuring input. Some of your solder joints could also use a bit more heat.
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Haha totally just realized the multimeter settings only after I took the picture, thank you for bringing that to my attention!
I appreciate your help - I have little experience with electrical work besides for the Crack so my ineptitude shines through fairly easily.
I just finished checking everything out and it passed all voltage checks! (After taking pics of the underside, the black wire from 3U to G had ripped from turning it too much - had to replace it and run testing again)
Thanks again PB! You're my hero.
I'm sure one day I'll have another question for you lol.
Appreciate the assistance,
- Ben
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The spark you saw didn't do any harm to the amp, and likely no harm to the meter either. Even if you toasted the current shunt element, it's not necessarily that useful anyway.
I'm glad everything worked out.
-PB