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Post by Time Lord on Mar 27, 2008 8:08:23 GMT -5
I had the thing working for about a half an hour last night. Then as I played it up and down and was making notes on which keys were still needing a cleaning... POP!  Back to the noisy output, but this time I can still hear a faint sounding of the notes. I am getting close, so close... |
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Post by Time Lord on Apr 1, 2008 22:12:46 GMT -5
I got it up and running last night! Still have a loose solder joint on the pre-amp board somewhere but I turned to corner. Then I have to get the volume pedal working. ;D
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Post by karl on Apr 1, 2008 23:43:08 GMT -5
Hey there Rod,
When looking for a cold solder joint:
If needed, then use a piece of cardboard to isolate the circuit board from any other boards or metal parts.
Turn unit on.
Use a pencil "eraser side down" to push on the circuit board, while monitoring the output. This keeps you from getting shocked. I guess a PDA pendent or anything non-metallic would work.
Push gently at various places on the circuit board while listening
through junk speakers. You can generally find the area where
the cold solder joint is.
Hope This Helps
Karl
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Post by Time Lord on Apr 3, 2008 8:00:39 GMT -5
Karl, I have been doing that for about a week. I have hit every joint on the board twice and still have an intermittent problem. I found a bad connection that I fixed two days ago and now it takes a major bump to pop it back out again. There are many components on the board that pop when you prod them. I am starting to wonder if there were lots of cold joints that have the ends of the components covered with oxidation. So even though I have reflowed the solder I still don't have a good connection. I am going to starting sucking the solder out of each popping thing and pulling the part out and cleaning the ends and re-soldering...  Still it sounded pretty good when I was playing it last night. Very in tune. I had most of the keys cleaned already so there are only a couple of dirty sounding ones. |
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Post by karl on Apr 3, 2008 22:30:24 GMT -5
Hi Rod,
I don't think you have to pull all the parts out. The flux in the solder cleans the metal surfaces to allow the solder to stick. However cleaning the old solder off is a good idea.
I have had to resolder every connection on a circuit board before, to get it working.
I would also check any electrolytic capacitors as these dry out over time, and become intermitant. Also a resistor can crack in the middle causing the same symptom. It's a hard way to go but I will gently pry at each resistor to see if it breaks apart. If you
break one by accident, well now you gotta replace it. This is usually a problem in tube amps where things get really hot, but
causes the same kind of symptom.
Hope this Helps
Karl
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Back to the noisy output, but this time I can still hear a faint sounding of the notes. I am getting close, so close...
