Re: Monitor Audio RSW-12 Schematics
�� These subs are too nice to not try and fix them.
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Re: Monitor Audio RSW-12 Schematics
This is the email for the office in the UK: [email]technical@monitoraudio.group[/email]Re: Monitor Audio RSW-12 Schematics<....group[/email]Leave a comment:
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Re: Monitor Audio RSW-12 Plate Amp Popping/Crackling
I think I found my problem. SMD resistor R31 is reading 56K instead of 16K. I replaced it with a 1/4W resistor I had on hand and the noise has cleared up. I was able to use the signal tracer to narrow down the problem to somewhere between the master PWM module U11 and the mosfets.
Thanks to those who helped me with their suggestions, I learned a lot working on this.
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Re: Monitor Audio RSW-12 Plate Amp Popping/Crackling
Redwire, thanks for the tracer link. I decided just to buy a kit, Velleman K7000, and have it together now. Yesterday I checked the things you mentioned earlier:
- βThe preamp limiter C27/Q2 I would make sure are U5A,B should be off so -ve V at the gate.β I measured -5V at Q2 gate and the function of Q2 checked out ok with diode tester.
- β You can listen to the preamp output CON1 SG to see if it is where the noise is. Next would be muting, on the amp board U10B Q10/C10.β No noise at these...Leave a comment:
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Re: Monitor Audio RSW-12 Plate Amp Popping/Crackling
Momaka, C14 is new, I replaced all the caps, but I will check it and all the others with the LCR meter. I also picked up a replacement for Q10 and all the other transistors on the board but have yet to install them.
I’ll also remove the last of the glue and check all the tracks. What’s the best way to remove solder mask, just scrape it gently with a blade?
I used freeze spray on the transistors and most other items on the AC-Shift board with no results. I then used it on the AMP board concentrating...Last edited by bmor; 01-22-2022, 10:30 AM.Leave a comment:
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Re: Monitor Audio RSW-12 Plate Amp Popping/Crackling
The outputs from regulators U15,16,17 all appear to be good.
I can pickup a signal tracer tomorrow but have never used one before. May need some help with that.Leave a comment:
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Re: Monitor Audio RSW-12 Plate Amp Popping/Crackling
I was wondering the same thing about the AC-Shift board and whether anything on there could cause the noise.
The voltage regulators are shown on dwg. AMP-041229, there’s 2 pages. Connector P12 assoc. with U15 and U16 connects to P10 on the AC-Shift board.
I’ll check the voltages tomorrow morning.Leave a comment:
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Re: Monitor Audio RSW-12 Plate Amp Popping/Crackling
Petehall347, I'll pickup some freeze spray on the weekend and read up on testing that way.Leave a comment:
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Re: Monitor Audio RSW-12 Plate Amp Popping/Crackling
Lotas, will do. Looks like I removed dried glue from those areas a while ago and maybe caused some damage.
....I've checked the traces, they seem to be ok.Leave a comment:
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Re: Monitor Audio RSW-12 Plate Amp Popping/Crackling
Hi Redwire, I agree with your first statement. I had already gone back and pulled them out and re-installed the caps on the amp board after I realized I didn't pay attention to it being a double sided board. I will check everything again.
The Q10 (mislabeled as Q11 on the schematic) does run very hot. I wasn't sure if the board dis-colouration was normal for the age of it. I had pulled it and tested it with diode tester on multi-meter and HFE and it seemed good, but I can get a replacement easily this weekend so I'll...Leave a comment:
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Monitor Audio RSW-12 Plate Amp Popping/Crackling
Hello all.
I need some help fixing this amp, I'm at the limits of my knowledge. The amp developed a hum a while back so I decided to change out the electrolytic caps which seemed to be a known issue. That worked well, got rid of the hum, but I now have popping/crackling when the amp board powers on, with no signal input to the amp.
I've checked for bad solder joints and fixed those I thought were suspect, pulled and tested the transistors from the AC-Shift board, pulled resistors where needed to test those in circuit better, measured other things everywhere that... -
Monitor Audio RSW-12 Schematics
Hi, I've been working on this subwoofer and got these from MA. Thought I would post them here in case anyone is interested. They told me there is no service manual.... -
Re: ReCap on a Monitor Audio RSW-12 Sub
I'll just keep them the same size, seemed to work well. Thanks for the help!Leave a comment:
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Re: ReCap on a Monitor Audio RSW-12 Sub
Sorry, last post didn't have the photo....Leave a comment:
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Re: ReCap on a Monitor Audio RSW-12 Sub
I guess I'll leave as much of the tape as I can in place while making sure the heatsink connection is 100%. On another topic, I'm replacing all the caps. Is there any advantage to increasing the size of the two 4700uf in the picture to a higher rating?Leave a comment:
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Re: ReCap on a Monitor Audio RSW-12 Sub
Good point, that whole edge does mount up against the metal back plate. I like your idea of extending the connection face, I'll probably try that. Thanks!Leave a comment:
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Re: ReCap on a Monitor Audio RSW-12 Sub
Thanks for the warning, good advice. It's a stick on foam strip on the edge of the board where it attaches to the backplate. I'd just remove it in the area of the heatsink attachment so it's not interfering with the connection, which it is now....Leave a comment:
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Re: ReCap on a Monitor Audio RSW-12 Sub
I'm recapping my RSW12 as well and as Mikay's photos pointed out, the heat sink mating surface connection is poor. Not enough paste and questionable contact over the whole surface. I estimate the paste coverage to be 25% at best on mine and there's a strip of black insulator material (seen in his photo) that probably prevents complete mating of the two surfaces. Seems to be a problem with these subs that I'll be correcting when re-assembling.Leave a comment:
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