Bman0202 Posted January 25, 2022 Share Posted January 25, 2022 Well to my dissatisfaction When I recieved the new components the new Q13 and q19 test the same. So I was wrong. Now im not sure what to look for. I cant seem to find where this ugly noise is coming from in the amp. I might just have to forfeit and purchase one of your repaired units and send you this old one for you to troubleshoot for another potential buyer Quote Link to comment Share on other sites More sharing options...
Bman0202 Posted January 25, 2022 Share Posted January 25, 2022 (edited) 45 minutes ago, Bman0202 said: Well to my dissatisfaction When I recieved the new components the new Q13 and q19 test the same. So I was wrong. Now im not sure what to look for. I cant seem to find where this ugly noise is coming from in the amp. I might just have to forfeit and purchase one of your repaired units and send you this old one for you to troubleshoot for another potential buyer Ok well since I have the component's Im gonna go ahead and change what I have and see what I get. After replacing q13, q19 and q14, q20 the noise in my previous pictures is still there. Next ill replace q7 U3 and u4 Edited January 25, 2022 by Bman0202 Quote Link to comment Share on other sites More sharing options...
Bman0202 Posted January 26, 2022 Share Posted January 26, 2022 (edited) After replacing q7 U3 and u4 The symptoms are still the same. There is something fishy happening in the amplifier cuircit and I can't find it. This is so frustrating Edited January 26, 2022 by Bman0202 Quote Link to comment Share on other sites More sharing options...
ngen33r Posted February 1, 2022 Author Share Posted February 1, 2022 On 1/26/2022 at 11:48 AM, Bman0202 said: After replacing q7 U3 and u4 The symptoms are still the same. There is something fishy happening in the amplifier cuircit and I can't find it. This is so frustrating Looks like the bias pots need adjustment. or the feedback to the opamps from the speaker terminals has a broken trace. Quote Link to comment Share on other sites More sharing options...
Bman0202 Posted February 1, 2022 Share Posted February 1, 2022 1 hour ago, ngen33r said: Looks like the bias pots need adjustment. or the feedback to the opamps from the speaker terminals has a broken trace. When I adjust the bias pots im not seeing a change in the noise on the scope really at all. Quote Link to comment Share on other sites More sharing options...
Bman0202 Posted February 13, 2022 Share Posted February 13, 2022 On 2/1/2022 at 11:31 AM, ngen33r said: Looks like the bias pots need adjustment. or the feedback to the opamps from the speaker terminals has a broken trace. After alot more troubleshooting I narrowed it down to q9 and d17 on the "speaker -" rail. D17 was ultimately dropping too much voltage. Messing with q9. I measures the 15 volts going in but only 8volts was coming out. Replaced and now its all good thank goodness. Clean waveform in and out. Adjusted the bias to make sure the wave form looks proper Thanks tho this forum ive gotten it back up and running Quote Link to comment Share on other sites More sharing options...
Bman0202 Posted February 14, 2022 Share Posted February 14, 2022 Also I must say. If I didnt have an oscilloscope, I wouldn't have been able to find this issue. The scope showed me the bad wave being introduced, as well as the voltage drop. With just a multi meter it would have still be possible but it would have been even more trial and error than what I went through. The scope is what saved me. Quote Link to comment Share on other sites More sharing options...
Bman0202 Posted February 16, 2022 Share Posted February 16, 2022 (edited) Well once I tested and confirmed everything I carefully applied neutral cure silicone to q5. And let it cure for about 6 hours and tested it and it seems ok. So I shut it down and it sat till today I turned it on and I had nothing. Took the plate off and tested it and I had no 5 volts As the silicone continued to fully cure it must have hardened and created tension and broke the traces on the board for q5. So no I have removed q5 and im going to begin fixing the broken traces and resecuring q5 and applying silicone and hoping that this time it doesn't pull more loose. Ugh! Edited February 16, 2022 by Bman0202 Quote Link to comment Share on other sites More sharing options...
Vafin Posted February 18, 2022 Share Posted February 18, 2022 Hello everyone I also have a problem. On resistors R70 r71. 70v. The resistors are very hot. Quote Link to comment Share on other sites More sharing options...
flyingtele Posted February 21, 2022 Share Posted February 21, 2022 Hello ngem33r, and firstly let me say thank you for such a helpful and informative thread. I work as an electronics repair tech and have also repaired many different BASH amplifiers, however this one has me stumped and I'm hoping you may be able to help. It is one of the Klipsch Synergy Sub 12 amps, that seems to feature on this thread the most. Problem with it is very low level audio only when gain control is at max. I have confirmed the power supply is working, measuring the two resistors by the ribbon connector I'm getting approx 3.43 volts from each rail to ground, or ~6.5 volts between them. Is this within spec? I have replaced Q5, tested the zener and its holding 13v drop, and I have replaced all capacitors. I removed the BASH board and tested all components individually and they all check out OK. Could this fault still be in the BASH drive circuit or is it more likely to be a fault in the output stage? Any thoughts or recommendations would be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
ngen33r Posted February 22, 2022 Author Share Posted February 22, 2022 On 2/18/2022 at 4:53 AM, Vafin said: Hello everyone I also have a problem. On resistors R70 r71. 70v. The resistors are very hot. Hot resistors mean bash control board needs repair. Quote Link to comment Share on other sites More sharing options...
ngen33r Posted February 22, 2022 Author Share Posted February 22, 2022 19 hours ago, flyingtele said: Hello ngem33r, and firstly let me say thank you for such a helpful and informative thread. I work as an electronics repair tech and have also repaired many different BASH amplifiers, however this one has me stumped and I'm hoping you may be able to help. It is one of the Klipsch Synergy Sub 12 amps, that seems to feature on this thread the most. Problem with it is very low level audio only when gain control is at max. I have confirmed the power supply is working, measuring the two resistors by the ribbon connector I'm getting approx 3.43 volts from each rail to ground, or ~6.5 volts between them. Is this within spec? I have replaced Q5, tested the zener and its holding 13v drop, and I have replaced all capacitors. I removed the BASH board and tested all components individually and they all check out OK. Could this fault still be in the BASH drive circuit or is it more likely to be a fault in the output stage? Any thoughts or recommendations would be greatly appreciated. Does rail voltage increase with the volume knob? You should be able to see it rise as the gain is increased. Quote Link to comment Share on other sites More sharing options...
flyingtele Posted February 25, 2022 Share Posted February 25, 2022 No it doesn't, and that's the problem. I am not sure if the audio signal is not modulating the power supply buck converter to track the output waveform, or if there is a fault in the audio output stage that is preventing the signal from passing through correctly, and the power supply rail voltage isn't changing simply because there is not enough gain. I did scope the audio signal from the preamp board to the main board and there is plenty of signal there. Do you know where the power supply modulation gets its signal from? Is there a control line from the preamp, or does it just 'listen' to the main amp output? Quote Link to comment Share on other sites More sharing options...
Vafin Posted February 28, 2022 Share Posted February 28, 2022 On 22.02.2022 at 07:08, ngen33r said: Горячие резисторы означают, что плата управления bash нуждается в ремонте. Do you have a diagram? At least give me advice where the malfunction is sitting. I examined the board and didn't find anything. Quote Link to comment Share on other sites More sharing options...
bucka Posted March 13, 2022 Share Posted March 13, 2022 On 7/18/2021 at 1:17 PM, LarryM said: I have a sub12 subwoofer. The auto on/off stopped working. It is always on. Do you know what I need to replace to fix this. The amp number is 119511. Thanks Caveat: I'm not even a novice. Heed nge33r's warnings about electrocution or even worse, lifting solder pads and otherwise damaging boards. According to @ngen33r, replace C41. Link below goes to relevant timestamp. Quote Link to comment Share on other sites More sharing options...
bucka Posted March 14, 2022 Share Posted March 14, 2022 Hi, I have a SUB 12S+ that powers on (there's a blue light) but doesn't drive the speaker. It's been on standby mode for years and probably hasn't worked for most of them. As per ngen33r's first video: the mosfets aren't shorted the gate drive resistors read 100 ohms voltage regulators read 26.3V I read 5.6v between the output resistors Q5 isn't surface mount, it looks like TO92 packaging I don't see anything obviously discolored or bulging I have a good soldering iron, a manual solder sucker, good sense about big caps and power rails, but very limited experience. I don't mind wrecking the board learning something or having it repaired if there's a good place (or if your queue ever dies down, @ngen33r). What would you recommend? Go after the caps, replace the glue, and re-test? Any suspicions of what died by keeping it in standby mode? Quote Link to comment Share on other sites More sharing options...
Hatsune Miku Posted March 24, 2022 Share Posted March 24, 2022 I have the rw-10d and the last 2 days have been attempting to check everything. I decided I'd check the 5v reg today and apply 5v to the left side. Success! The 5v reg was dead. For some reason I decided to apply 15v to the right side to verify it was dead. Now the 5v rail is shorted to gnd after the regulator. I snipped the output leg of the regulator so that's not where the short is. What else could have been shorted? I unplugged the ribbon to the plate amp. So the board with the 5v reg has a short somewhere. My power supply was limited to .2a The diode above the 5v reg isn't shorted but doesn't measure .6v anymore it's 1.2v now. Maybe it's always been that way, I didnt check it before. Quote Link to comment Share on other sites More sharing options...
Stas Posted April 4, 2022 Share Posted April 4, 2022 Hey ngen33r, thanks for your help. I have Klipsch R-12SW, cant find information on internet how to fix this sub nor in this forums. The sub turning on, green light but no sound. The glue is white and fresh and i think is not conductive, it was bought a year ago and stopped working after few weeks, since then it is not working. The secondary side is not working, no output on the +g- that goes to the amp board. Checked every possible thing and cant find the problem. Please help Quote Link to comment Share on other sites More sharing options...
SuperBrainAK Posted May 11, 2022 Share Posted May 11, 2022 Hey all I have a Sub 10 here and the PSU and amplifier section I think are working perfectly, I have the right voltages in all the right spots 86.8v main supply 27.71v into the regulators 5.55v between the big resistors, the balance trim pots are 250 ohms each. The problem is there is just no sound coming out, when I connect a phone audio directly to what I believe is the input to the amp section using the JST connector pins furthest from the regulators I get a tiny amount of sound with the phone cranked all the way up. I then tried the same phone with the pre amp board attached and the gain all the way up I get the same amount of sound. What could be the issue here? I dont see any bad capacitors and for a sub there wouldnt be any in series to the audio correct? In what is typical for a high pass filter. Any help would be greatly appreciated, I can post pics here or videos to my YouTube if needed thanks. Quote Link to comment Share on other sites More sharing options...
Stas Posted May 12, 2022 Share Posted May 12, 2022 (edited) On 4/4/2022 at 10:53 AM, Stas said: Hey ngen33r, thanks for your help. I have Klipsch R-12SW, cant find information on internet how to fix this sub nor in this forums. The sub turning on, green light but no sound. The glue is white and fresh and i think is not conductive, it was bought a year ago and stopped working after few weeks, since then it is not working. The secondary side is not working, no output on the +g- that goes to the amp board. Checked every possible thing and cant find the problem. Please help Replaced PWM IC OB2269, now it is working like new Edited May 12, 2022 by Stas Quote Link to comment Share on other sites More sharing options...
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