Oh! That reminds me of funny story.
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another "BA115 keeps blowing fuses" thread!
- Thread starter Execut1ve
- Start date
I punched out an LCD display at work a couple of years ago. Hit it about 5 times, then went home.
A few weeks ago I threw down about 5 keyboards after none would work on my high end work station. Not a PC, a $4000 work station. Keys were all over the floor.
In both cases, it helped. Didn't fix anything. But I sure felt better. Go ahead and hit it.
I used to have a small hammer that I would whack computers with. Good way to test circuits.
I've got a US made lead hammer in my machine shop. Found it at Horrible Freight of all places. An essential item for machines to tap stuff home, open grumpy handles, etc. A dead blow hammer just won't work. It came with a label indicating the State of California thinks it could be harmful to your reproductive organs. Why would anyone swing that thing anywhere near their reproductive organs? And if they would, perhaps they best not reproduce.
Did you tap the housing or the side of the circuit board ?
Initially it was a SUN microsystems unix box. It had a card cage that memory and other boards plugged into. The pins that plugged in to the backplane connector for a graphics board barely made contact. Perhaps it was out of spec. Every once in a while it would act up. A stiff whack in the back would do more good than the service guy could accomplish. From there the tradition began.
I have been known to hammer an amp chassis like they did at Mesa.
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- Feb 12, 2006
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- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
It's even more fun blowing stuff up
Cats are cute but you never want to give them your password. You never know what they’ll do when they can access your online account.
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Yup, that one's on Amazon with a saved credit cart, ordering all the catnip real fast. Nothing worse than an addict after your money.
If you train them they can do the repairs for you without breaking the manufactures seal on the chassis.
Roland GR 88
Commercial User
sorry for the lack of updates recently, gang - real life obligations have encroached on my tinkering time lately.
The bridge rectifier passed a more rigorous round of testing, so it has an alibi for now.
I went ahead and pulled the output mosfets and transistors to test them - both mosfets are shorted drain to source. Replacements are on order. The transistors tested fine but I ordered a new set of them as well just in case.
And, just to satisfy the good preacher who lectured me about doing my own math...
The two legs coming out of the bridge rectifier should measure +40V and -40V, for a net of 80V. DC voltage from a full wave bridge rectifier with no load should be very close to the peak AC voltage coming in, less diode drop. Allowing 1V for the drop across 2 diodes, this means peak AC voltage should be about 81V on the transformer secondary. Converting peak voltage to RMS gives about 57V RMS, which is very close to what I measured with a multimeter.
Hopefully that gives you enough to work with - please go ahead and make some posts about all the stuff I'm doing wrong and how I'm sure to shoot my eye out or something!
The bridge rectifier passed a more rigorous round of testing, so it has an alibi for now.
I went ahead and pulled the output mosfets and transistors to test them - both mosfets are shorted drain to source. Replacements are on order. The transistors tested fine but I ordered a new set of them as well just in case.
And, just to satisfy the good preacher who lectured me about doing my own math...
The two legs coming out of the bridge rectifier should measure +40V and -40V, for a net of 80V. DC voltage from a full wave bridge rectifier with no load should be very close to the peak AC voltage coming in, less diode drop. Allowing 1V for the drop across 2 diodes, this means peak AC voltage should be about 81V on the transformer secondary. Converting peak voltage to RMS gives about 57V RMS, which is very close to what I measured with a multimeter.
Hopefully that gives you enough to work with - please go ahead and make some posts about all the stuff I'm doing wrong and how I'm sure to shoot my eye out or something!
