ngen33r Posted November 29, 2019 Share Posted November 29, 2019 Hello All I have been repairing Klipsch subwoofer amps for about 15 years as a hobby. I have decided to start blogging my repairs and eventually do videos of each one. This thread is intended to be a blog and a resource for information. I will try to answer repair questions as best I can. Comments and tips are also welcome, If you do not have the experience or the tools, PLEASE do not attempt any of these repairs. You will only end up damaging the board and it will end up costing more for a tech to repair the damage. If you do not have a high quality vacuum desoldering station (Hakko or Weller) and a current limited mains supply, you should not be working on these amps. These subwoofers do not have any user serviceable parts inside. If you open up the sub or attempt any repair you see in this thread, you are doing so at your own risk!!! Quote Link to comment Share on other sites More sharing options...
ngen33r Posted November 29, 2019 Author Share Posted November 29, 2019 RW-12D PLATE SERIAL A308380152 This amp had a power supply failure due to the glue used to secure the parts becoming conductive. The PDC board needed to be rebuilt and all the glue removed. The fets were replaced and the power supply was recapped. Parts were secured with GE silicone II. Quote Link to comment Share on other sites More sharing options...
001 Posted November 29, 2019 Share Posted November 29, 2019 great idea to start a thread like this. lots of these subs out there that are dead & like many other brands of amps & sub plate amps, the glue they used causes most the issues. i have the rw-12d & am sure the glue on the area you have circled is what killed mine. im in the process of cleaning it up & was wondering if you can confirm any other locations that had the bad glue? is it the yellowish-tan glue around the caps & other parts that is the main issue or the dark brown stuff on that small board you have circled? also can you say what you use to remove it? its nasty stuff & so far only physically chipping it away has removed it. mine blew the little round green thermistor too. Quote Link to comment Share on other sites More sharing options...
ngen33r Posted November 30, 2019 Author Share Posted November 30, 2019 8 hours ago, EpicKlipschFan said: great idea to start a thread like this. lots of these subs out there that are dead & like many other brands of amps & sub plate amps, the glue they used causes most the issues. i have the rw-12d & am sure the glue on the area you have circled is what killed mine. im in the process of cleaning it up & was wondering if you can confirm any other locations that had the bad glue? is it the yellowish-tan glue around the caps & other parts that is the main issue or the bark brown stuff on that small board you have circled? also can you say what you use to remove it? its nasty stuff & so far only physically chipping it away has removed it. mine blew the little round green thermistor too. Anywhere that the glue has started to turn brown needs to be fully removed. The best way to remove it is to use hot air at 150C and a dental pic to remove it when it gets soft. The control board needs to be removed and thoroughly cleaned. The Chinese capacitors on these are about at end of life and should also be replaced, especially if you never power the system fully off. The switch is installed for a reason. The standby mode does not fully power off the unit and I know 99% of us do not turn our subs off. 1 Quote Link to comment Share on other sites More sharing options...
psyrexer Posted December 20, 2019 Share Posted December 20, 2019 (edited) On 11/29/2019 at 8:25 PM, ngen33r said: RW-12D PLATE SERIAL A308380152 This amp had a power supply failure due to the glue used to secure the parts becoming conductive. The PDC board needed to be rebuilt and all the glue removed. The fets were replaced and the power supply was recapped. Parts were secured with GE silicone II. Hello, i have the same power supply unit on my SUB and of course is dead. Can you give a bit more information about rebuilding this board? i need to replace all elements and also replace all 4 mosfets? that should help? I can provide pictures. i didn't find any color change on black glue they are using... Edited December 20, 2019 by psyrexer Quote Link to comment Share on other sites More sharing options...
ngen33r Posted December 23, 2019 Author Share Posted December 23, 2019 On 12/20/2019 at 6:09 AM, psyrexer said: Hello, i have the same power supply unit on my SUB and of course is dead. Can you give a bit more information about rebuilding this board? i need to replace all elements and also replace all 4 mosfets? that should help? I can provide pictures. i didn't find any color change on black glue they are using... First all the glued components need to be removed and the yellow glue on the board needs to come off. These boards only have 2 mosfets. You have to do some testing to find the location of the failure. The boards have multiple power supplies after the transformer. You have to start at the end and work your way back to find the issue. Blowing fuses is almost always before the transformer. If you don't have a vacuum desoldering tool, I wouldn't attempt the repair. The boards are made in China and the thru holes rip easily off the board. Thru hole parts don't last very long with vibrations if they are not securely soldered. The only proper way to fix this is to replace the thru hole and resolder. Jumper wires, solder blobs and all of those other types of repairs are hack jobs and should be avoided. These units are getting old, they should be recapped at this point if you are servicing it. Quote Link to comment Share on other sites More sharing options...
MechEngVic Posted December 24, 2019 Share Posted December 24, 2019 23 hours ago, ngen33r said: First all the glued components need to be removed and the yellow glue on the board needs to come off. These boards only have 2 mosfets. You have to do some testing to find the location of the failure. The boards have multiple power supplies after the transformer. You have to start at the end and work your way back to find the issue. Blowing fuses is almost always before the transformer. If you don't have a vacuum desoldering tool, I wouldn't attempt the repair. The boards are made in China and the thru holes rip easily off the board. Thru hole parts don't last very long with vibrations if they are not securely soldered. The only proper way to fix this is to replace the thru hole and resolder. Jumper wires, solder blobs and all of those other types of repairs are hack jobs and should be avoided. These units are getting old, they should be recapped at this point if you are servicing it. How do you replace the thru holes? I take it these boards are not multi layered? Quote Link to comment Share on other sites More sharing options...
ngen33r Posted January 1, 2020 Author Share Posted January 1, 2020 The boards are 2 layer. If you tear a thru hole off it has to be repaired with a thru hole repair kit and the proper sized eyelet. You can use jumper wires and epoxy, but I consider that a hack job and not a proper repair. Keep in mind this is only if you damage the board. In my experience solder wick almost always tears a pad off of these boards. Quote Link to comment Share on other sites More sharing options...
ngen33r Posted February 10, 2020 Author Share Posted February 10, 2020 RW12D PLATE SERIAL A306280444 This amp was recently sent in by a forum member. It is a perfect example of why NOT to attempt the repairs if you don't have the proper tools. Nothing against them or their workmanship, but you MUST have the tools for the job or it is going to cost you more. This amp failed from the glue plague. The PDC control board was damaged and the 5V supply was not working. The customer tried replacing the capacitor on the secondary output and tore out the via with the cap. You cannot solder the cap in properly without a plated thru hole. These large snap in thru holes are a pain to replace. I repaired the board and PDC, replaced the FETS, replaced the NTC and did a full recap. Quote Link to comment Share on other sites More sharing options...
dudaindc Posted April 23, 2020 Share Posted April 23, 2020 (edited) Great information in this thread - thank you! I need some help regarding D23 (2005 pcb) and D30 (2006-207 pcb) in the pre-amp board. Since I do not have (and cannot find) schematics for the RW10-D/RW12-D amps, I was wondering if you happen to know the actual model for these diodes. D23 seems to be 843 (or B43) and D30 seems to be B4U. Looking at SMD codes, I cannot find any diodes that would match those markings. Any suggestions? Thanks in advance. Edited April 23, 2020 by dudaindc Quote Link to comment Share on other sites More sharing options...
babadono Posted April 25, 2020 Share Posted April 25, 2020 On 4/23/2020 at 4:28 PM, dudaindc said: Any suggestions? Get a tech at Digikey or Mouser on the phone to help you search. I have had success ID ing parts this way. Quote Link to comment Share on other sites More sharing options...
ngen33r Posted April 28, 2020 Author Share Posted April 28, 2020 On 4/25/2020 at 1:55 AM, babadono said: Get a tech at Digikey or Mouser on the phone to help you search. I have had success ID ing parts this way. The techs there have cross referenced me parts that were not correct and have caused hundreds in extra damage. I will never make that mistake again even if it was bad luck. Do some homework and use the available resources https://www.sphere.bc.ca/download/smd-codebook.pdf http://www.s-manuals.com/smd/b4 B4 BZX399C2V4 Phi I SOD323 2.4V 0.3W zener B4 SOD-123F BZT52H-C2V7 NXP Zener diode I would start with that. Keep in mind that I have never had to replace one of those diodes EVER!!! Putting 5V to the output leg of the VREG and ground to the plate should power on the LCD and confirm that diode to be good. Quote Link to comment Share on other sites More sharing options...
dudaindc Posted April 28, 2020 Share Posted April 28, 2020 (edited) 19 hours ago, ngen33r said: The techs there have cross referenced me parts that were not correct and have caused hundreds in extra damage. I will never make that mistake again even if it was bad luck. Do some homework and use the available resources https://www.sphere.bc.ca/download/smd-codebook.pdf http://www.s-manuals.com/smd/b4 B4 BZX399C2V4 Phi I SOD323 2.4V 0.3W zener B4 SOD-123F BZT52H-C2V7 NXP Zener diode I would start with that. Keep in mind that I have never had to replace one of those diodes EVER!!! Putting 5V to the output leg of the VREG and ground to the plate should power on the LCD and confirm that diode to be good. NGEN33R, thank you! I had the same experience with Digi-Key... nevermore! Before asking for help, I try to exhaust all resources - that is how I learn. I definitely overlooked that zener because the PCB did not have a "Z#" but a "D#" marking - while a zener is a diode, other Klipsch boards I have seen make a distinction. Besides, there are other diodes with the same marking B4: http://www.marsport.org.uk/smd/smdb.htm I was not believing my SMD "tweezer tester" which was telling me that D23 was no good. Once I removed D23 and tested it out of board, it was bad... no clamping at 2.4V at all... I guess that there is always a first time. Thanks again for your time! Edited April 28, 2020 by dudaindc Quote Link to comment Share on other sites More sharing options...
ngen33r Posted April 29, 2020 Author Share Posted April 29, 2020 Thinking about this more, that might not be a zener. Typically a zener is not placed across an LDO like that I am guessing that is a protection diode. https://www.onsemi.com/pub/Collateral/MBR0540T1-D.PDF Quote Link to comment Share on other sites More sharing options...
dudaindc Posted May 3, 2020 Share Posted May 3, 2020 (edited) On 4/29/2020 at 4:28 PM, ngen33r said: Thinking about this more, that might not be a zener. Typically a zener is not placed across an LDO like that I am guessing that is a protection diode. https://www.onsemi.com/pub/Collateral/MBR0540T1-D.PDF I agree and believe this to be a Schottky, but the diagram only applies to the new boards and not to the older ones. For the latter, the diode is in series with the output of the regulator as if trying to create a 4.3V for the volume control chip. I posted pictures of both (see previous post), but I took a better one. Edited May 4, 2020 by dudaindc Quote Link to comment Share on other sites More sharing options...
delhite2 Posted August 8, 2020 Share Posted August 8, 2020 @ngen33r My rw12d suffered the same fuse blowing issue. I opened it and saw diagnosed blown mosfet q402, as a precaution i changed q401 too. My thermistor seems fine. I have removed all the brown glue around PDC too, the PDC looked Ok. But now even though it's not blowing fuses I am not getting any outputs from the transformer. In your opinion, do u think its the PDC? I have removed the PDC, apart from diac, what all should I check or a rebuild is necessary? If possible can u measure the voltages at transformer input and also the 8 pins for PDC, and tell me what should I measure the voltages against? Is it possible that component values of resistors and capacitors are different in the same 660038ra board according to the amplifier they are used in? Quote Link to comment Share on other sites More sharing options...
delhite2 Posted August 9, 2020 Share Posted August 9, 2020 I checked and atleast the zener diodes are not working, I can't check the diac though. The diac says DB6, the datasheet says HT60, and you have used NTE 6412. I have also ordered q403/q405 transistors to be on safe side. Attached the schematics, I believe the power board, PDC should be same across both variants, the RW12 & RW12D. klipsch_rw-12.pdf Quote Link to comment Share on other sites More sharing options...
ngen33r Posted August 16, 2020 Author Share Posted August 16, 2020 The DIAC is usually the issue if the PDC is not working. Quote Link to comment Share on other sites More sharing options...
delhite2 Posted September 5, 2020 Share Posted September 5, 2020 On 8/16/2020 at 8:16 AM, ngen33r said: The DIAC is usually the issue if the PDC is not working. Hi, i got the amp to work... Or atleast have the display...because once it turned on I left it there without connection to driver for 15 minutes when one of capacitors I had changed blew suddenly,. The cap in question is c435., these are 4 identical capacitors which I had changed earlier with code 104 (0.1 uf) because that's what was written on original removed cap, but I just noticed schematic says 1uf and 100v. Whats the right capacitance and what voltage? Also my LCD is kind of dim, the back light is fine but lcd character are dim, adding a polariser will fix it? Or is there something else I should try. Quote Link to comment Share on other sites More sharing options...
Qwerty Posted September 19, 2020 Share Posted September 19, 2020 I saw this thread and as I have the same issue with my RW12D. Blowing fuses etc. I do not have the soldering equipment you reference. Do you repair these boards? Before I mess it up trying? Thanks. Quote Link to comment Share on other sites More sharing options...
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