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No power on this one. Wasn't able to locate a schematic. I believe I remember it had some voltage readings from transformer. Would appreciate some help getting this one out of here if possible.
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I'd wager this is a fairly simple amp inside. A power amp IC on a heat sink, and one or two dual op amp ICs???
Power supply should be easy to find in any amp. Transformer secondary gets rectified and filter capped, and that is for the power amp. Then those two supplies are further regulated down to 15v supplies, typically with 7815 and 7915 or similar. Once in a while, 12v instead of 15v.
When you say "no power", do you mean absolutely no sign of life? Or do you just mean no sound?
Nothing works without power, so find the supplies and make them work. Power amp ICs are not repaired, they are replaced, so if you get signal to the input pin, and it don't come out, replace.Education is what you're left with after you have forgotten what you have learned. -
No power onComment
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Does "voltage readings from transformer" mean voltage measurements or voltages written on the transfomer.Comment
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Voltage measurements near transformer.Comment
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On any amp: you start with the power transformer. The secondary leads either have voltage or they do not. For a small amp, maybe 20-25vAC more or less. That will then be rectified, so either a small bridge rectifier or four diodes. Either way, they turn the AC into DC, and you should find both positive and negative. Then ther will be a pair of filter caps - one for each polarity. They have DC on them or they don't. If they do, does it reach the power amp IC?
Then ther will be low voltage su-pplies for the preamp, usually just dropped from the main DC supplies, they will be regulated, either with a pair of three legged regulator ICs, or maybe a zener diode for each.Education is what you're left with after you have forgotten what you have learned.Comment
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If it's for your consolation, he doesn't even know what he wanted to sayOriginally posted by J M Fahey View PostIt's All Over NowComment
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TROLLComment
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This guy?When the going gets weird... The weird turn pro!Comment
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Originally posted by Jazz P Bass View PostFind all started topicsOriginally posted by vintagekiki View PostWelcome to the machine.
In 2 weeks he opened 8 different threads in which he fixes something. Judging by his comments, from experience he have only good will.
https://music-electronics-forum.com/forum/amplification/guitar-amps/maintenance-troubleshooting-repair/928711-fender-fm15dsp-no-output?p=928747#post928747
https://music-electronics-forum.com/search?searchJSON=%7B%22authorid%22%3A%5B%2239458%22%5D% 2C%22channel%22%3A%222%22%2C%22exclude_type%22%3A%5B%22v BForum_PrivateMessage%22%2C+%22vBForum_Channel%22%5D%2C% 22starter_only%22%3A%221%22%7DIt's All Over NowComment
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Wouldn´t go that far, but definitely biting more than he can chew.Originally posted by Jazz P Bass View Post
Personally I would focus on ONE project, suggest the 10W Genz Benz amp, and try to solve it in full.
Leave all others for a later date.
Start by providing some gut shots, showing PCB and front panel, both inside/outside.Juan Manuel FaheyComment
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It just seems to me that the OP is providing no information.
"HI. My amp doesn't work."Comment
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Agree. The answers given are cryptic at best. I have yet to see a clear/concise answer to any question posed in any of the OP's threads. I thought maybe a language barrier or translation error, but am starting to wonder. There's no location in the OP's profile, so it's hard to say. I also find it odd that anyone would be working on so many different projects simultaneously. Most techs I know like to see a project through before moving on to something else. My solution is to avoid getting involved in these threads. It seems like it would only create frustration.
Just look at this thread, for example.
No power
No schematic
MIGHT have had "readings" from transformer
Voltages "near transformer"
Absolutely zero useful information- same as the rest of the OP's threads.Last edited by The Dude; 04-16-2021, 10:15 PM."I took a photo of my ohm meter... It didn't help." Enzo 8/20/22Comment
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Apparently a "Hard Luck Charlie." What our UK friends refer to as a "timewaster."Originally posted by vintagekiki View PostThis isn't the future I signed up for.Comment
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