KEF PSW 2150 Need Schematic

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Good evening,
I started out with a bad filter capacitor for the 'muting' relay then after a few hours of normal operation one of the power transistors shorted. In the process of making that repair I found that the heat sink to the out side of the case only had about 1/3 of the area covered with thermal compound. I did move the +- 15 volt regulators on to the same heat sink as the power transistors hoping to reduce some of the internal heat build up. If possible I would like to add a small fan to help lower the internal temperature. I'm about ready to put the amp back into service when i have a few spare minutes.

If you do not have a schematic for your amp I do have one available and would post one to you if you need it. I tried to ansewer you directly but I guess I haven't posted enough times to do that.

If I can off any more assistance please let me know. Sometimes I can be a little slow in answering as I am medically retired and some times I'm not up to checking my mail but I do get to eventually.

Regards,

John
 
Kef psw2150

Good evening,

I have had a coupe problems with my sw. The transformer went bad. then two filter caps were swelled up. I replaced them a few years ago but now I have no sound what so ever coming out. does anyone have any ideas on what could be wrong or does anyone have a schematic for the amp? I want thak you ahead of time or what you can do to help me. THANK YOU.

From Brad
 
I know this is a bit of an old thread, but maybe you can help. I have this sub and it seems to work fine, then after a bit of playing...anywhere from 30min to an hour, I'll get a strange hum, buzz, distortion noise through it. It appears to be regardless of source, and it will continue even if the receiver is turned off. My best guess is something in the power supply, but I don't know for sure. It will last anywhere from 1 second to however long it takes me to jump up and unplug it. When it goes away or when I plug it back it, it plays just fine. Any suggestions on where to start? I have a service manual for it and I don't mind replacing PCB components. Thanks for any help you can offer.
 
Good evening,
I started out with a bad filter capacitor for the 'muting' relay then after a few hours of normal operation one of the power transistors shorted. In the process of making that repair I found that the heat sink to the out side of the case only had about 1/3 of the area covered with thermal compound. I did move the +- 15 volt regulators on to the same heat sink as the power transistors hoping to reduce some of the internal heat build up. If possible I would like to add a small fan to help lower the internal temperature. I'm about ready to put the amp back into service when i have a few spare minutes.

If you do not have a schematic for your amp I do have one available and would post one to you if you need it. I tried to ansewer you directly but I guess I haven't posted enough times to do that.

If I can off any more assistance please let me know. Sometimes I can be a little slow in answering as I am medically retired and some times I'm not up to checking my mail but I do get to eventually.

Regards,

John
Hi - I am attempting to resurrect this old thread to see if I can get some help for my 2150 PSW. It lights up and seems to sense the input, but I get nothing for output....any help is appreciated!!
 
Hi Kwaskow,

I have the KEF PSW 2150 as well. It worked fine for about 4 years and recently, when you first send a signal by turning on the receiver, all you hear is a buzzing sound. When sound signals are actually sent from a movie / game, etc there is cracking and popping.

It would be nice to see a schematic and or advice from someone who know's what parts could be bad. Possibly how to diagnose?

Thanks,
Garrison777
 
I know this thread is old, but I'll toss out my experience for anyone listening. I've had the psw2150 for 5 years, a couple years ago it started the dreaded "buzzing" that people talk about, and I just put it away. A couple months ago I read more about the problem, and decided to try the capacitor repair that is talked about. That worked, so if your sub is making a loud buzzing sound from the plate amp, replace the C52 capacitor. This worked for a few weeks, but just tonight it died. It's not that capacitor this time, it's something else. It powers on, but no sounds. The no sound was preceeded by several "pops" while playing, and then one loud one and it was silent. Hopefully this forum can help me out. I have yet to test the driver, but I'm pretty sure it's the amp.
 
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Mine had a trace blown. It was the input to a linear regulator. It was right where the wire solders to the pcb. I soldered 2 wires twisted together (for more copper) from the thru hole where the wire solders to the PCB, to the input pin of the lin reg.
 

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