Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: thdewitt on May 20, 2014, 12:22:09 PM
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Hello,
I have enjoyed my crack for a few months and decided to install the speedball. After assembly on first power up, i got smoke from r2 resistors on both boards and from the mje350's. I have ordered new parts from Mouser (4 of each just in case). I have taken the 3 boards off and checked all my wiring and components and I can't seem to find the problem. I do have a few questions.
1) One of my small boards has 3 holes next to the G. The r2 goes in the center. Can I put the other wire in either hole since one has been cut off the board.
2)The B+ holes on the big board are very close together and at this point are shorted together from taking the boards in and out. Is that a problem.
3) The two holes next two each other on both the O and G points on the big board are close and shorted as well. Is that a problem.
4) What parts do you recommend I replace before reinstalling so I don't just blow up the next batch of parts. Any ideas on ways to test. I do have a oscilloscope, function generator, DMM, and variable power supply if any of this equipment will help to test.
Thanks,
Tom
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1. The three paralell holes to the right of R2 are all shorted and equal.
2. The B+ holes on the large board are shorted.
3. Those are shorted.
I made these same observations and wondered if they could be problems. These are design choices.
It has not lead to problems soldering. You might notice that solder flows to adjacent shorted connection points. Not a problem as long as they are not covered as You could have problems installing leads. A solder wick would solve that too.
I also fried components due to bad soldering. I thought my soldering looked good and did not check that they actually conducted with my DMM. Bad move.
I would measure resistances if You didnt already as some kits have been shipped with wrong resistors causing them to fry.
Then, of course, I also had TONs of help from Caucasian Backplate
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I have enjoyed my crack for a few months and decided to install the speedball. After assembly on first power up, i got smoke from r2 resistors on both boards and from the mje350's.
Did you measure the R2's to be 150K?
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I thought I measured them but cant be sure now. I know I measured most resistors because they were too small to read. When I removed them they were completely wrong at that point 3K or something like that.
Tom
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I would measure resistances if You didnt already as some kits have been shipped with wrong resistors causing them to fry.
Am I right in assuming that you use the original Crack Manual to test the resistance? I would need to reinstall the 3 boards and then use the same points as the original crack to test the resistance?
Thanks,
Tom
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Actually, I meant more like what CB asked. If You really are certain that the proper resistors were in place before it went haywire. When I did my troubleshooting, I checked and doublechecked all resistors.
Luckily You can do as I did and revert to stock crack for the time being. It is more than enjoyable.
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Just in case anyone is interested. The R2 resistors that came with my crack kit were the wrong resistors, that is why they burnt out. Once I got the new ones from Mouser and put them in, everything is working fine. Thanks for everyones help.
Tom