Bottlehead Forum
Bottlehead Kits => Legacy Kit Products => Foreplay III => Topic started by: khingila on April 11, 2011, 03:55:40 AM
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i'm trying to get ready to go to work, and suddenly realise i've got a dead channel on the stereo; i've isolated it down to my extended foreplay III, which has been in problem-free use for several months. the leds on the b-side of one channel's pc board are not lit up, and i wonder if anyone can give me some suggestions for starting to troubleshoot the issue. thanks,
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Give us voltage and resistance readings, per the manual.
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thanks; i'll do so when i'm back home this evening.
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all resistance readings are as per the manual; ditto voltages, with the exception of #31, where i'm reading 1.5 volts. not too surprisingly, 31 connects to the uncooperative B side of the C4S board. is solder joint reheating in order, or does this info suggest some other avenue of pursuit?
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OK, you have a PC board so it must be an Extended Foreplay, right? :^)
That point should be connected to the "B" side terminal pf the PC board labeled "O". It should also be connected to the tube socket pin 8. It could be those connections are no good; less likely a bad tube, and also less likely a damaged transistor (MJE340) on the board.
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swapping tubes lights up everything; that suggests to me that maybe my pin 8 solder joint is tenuous, and that jostling it has (temporarily) restored continuity...does that make sense?
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Could be. Could also be a bad socket connection - a search will turn up many posts on cleaning and tightening socket connections, and on cleaning tube pins. Anyhow, glad to hear it's working again!
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thank you, sir.