Crack - Voltage Test issues

mtofsrud · 1458

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Offline mtofsrud

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on: July 03, 2018, 05:23:21 PM
Hi, hopefully I'm putting this question on the right place.

I completed my Crack build. My wall voltage was 123V when tested so built as per page 25 (Greater than 115V and less than 130V). Once the build was complete I did my resistance checks and all were in line. I then moved to the voltage check which is where there seems to be issues. They read as follows:

Terminal 1 : 188V
Terminal 2: 387V
Terminal 3: 0V
Terminal 4: 390V
Terminal 5: 184V

Terminal 6: 0V
Terminal 7: 241V
Terminal 8: 0V
Terminal 9: 243V
Terminal 10: 0V

I'm confused why these are so high. Any ideas where to go from here? Would appreciate your help.

Mark



Offline Paul Birkeland

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Reply #1 on: July 04, 2018, 05:46:09 AM
I would suspect that along the string of black wires that connect from the two 6-lug strips up to the headphone jack, then over to the front 5-lug strip, that you have a bad solder joint that isn't well connected. The most common place for this is where the black wires meet at the headphone jack.

If one of those wires is loose, it will often appear that you have very high DC voltages.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline mtofsrud

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Reply #2 on: July 04, 2018, 06:27:29 AM
Great thanks for this. Will give it a try and report back. Much appreciated.



Offline mtofsrud

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Reply #3 on: July 21, 2018, 03:46:26 PM
Arg. so, I've finally got a chance to sit down with my Crack again and investigate my voltage issue. Went thru instructions again and saw that the 22.1 kohm resister was put in backward on the 1U/2U location.  So I un-soldered the joint and removed the resistor (success!). In the process of straightening out the leads...I snapped one off! Ugh. So, first .... Can you put a resistor in backward? Was I wasting my time doing this? I was comparing my build to the manual pictures and picked this 'mistake' up and secondly...does Bottlehead sell spare resistors like this? I don't see any listed in the spare parts area of the site. Or can anyone send me in the right direction on ordering some new ones (more spares to be safe, lol) online?



Offline Julyan9

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Reply #4 on: July 21, 2018, 09:37:51 PM
Arg. so, I've finally got a chance to sit down with my Crack again and investigate my voltage issue. Went thru instructions again and saw that the 22.1 kohm resister was put in backward on the 1U/2U location.  So I un-soldered the joint and removed the resistor (success!). In the process of straightening out the leads...I snapped one off! Ugh. So, first .... Can you put a resistor in backward? Was I wasting my time doing this? I was comparing my build to the manual pictures and picked this 'mistake' up and secondly...does Bottlehead sell spare resistors like this? I don't see any listed in the spare parts area of the site. Or can anyone send me in the right direction on ordering some new ones (more spares to be safe, lol) online?

Resistors are blind to the polarity in a circuit. You cant put it in backwards.

Your local electronic store might have these in stock.
« Last Edit: July 21, 2018, 09:40:39 PM by Julyan9 »



Offline Paul Birkeland

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Reply #5 on: July 22, 2018, 07:20:19 AM
You can contact replacementparts(at)bottlehead(dot)com.

When the manual isn't specific about the directionality of a part, it's OK to assume it isn't important.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man