Journey Posted December 22, 2020 Share Posted December 22, 2020 (edited) Hi Guys, New to the forum here ... A bit of an introduction would seem appropriate ... I am a musician of 45 years and have worked on a lot of audio gear ... I worked for 5 years at a medium sized electronics manufacturer in Canada (1996-2000ish) where I did a lot of troubleshooting on digital stuff and a bit of RF. Our company made the studio famous RADAR unit marketed and sold by Otari, 24 track digital hard disk recording unit. That company was Creation Technologies out of Burnaby BC. Since working there I have been working here and there mostly as a musician but of late posted an Ad on Kijiji and have been fixing lots and lots of different stuff. Lots of vintage keybrds and receiver/amp combo units. The next interesting item I have coming in soon is a vintage radio circa 1947 ... I have a drum machine from 1967 here s well that is still a problem ... someone tried to fix but made a real mess of it. So ya ... I have ZERO fear when it comes to taking on tough jobs and in many cases, I end up working for like 2 bucks an hr just to keep gaining experience on everything and anything that walks through my door. A lot of stuff that comes in the door is stuff where there are no schematics or service manuals ... and not many if any utube vids to provide any tips. So on many jobs ... I'm Luke Skywalker flying by the seat of my pants using the Force and my cheap Chinese made soldering equipment keeps failing ! Don'y buy from China !!! Actually I still do have a Chinese made hot air station that amazingly is still working ... thank GOD ! ... Unfortunately the highest temp is only 450C ... not quite as good as the Hakko units I had used at Creation Tech. I also had a kickass binoc microscope which would be REALLY nice now that my vision is totally screwed from actually using that microscope for the 5 years I worked at Creation. So I guess enough about my boring history ... I hope I can contribute here as much as possible even if it's not a Klipsch product and look forward to getting to know some folks here. I'm currently working on an RT-12D with no power issue. I saw the post bout the amp brd and the burnt resistors so to answer ... R100 and R101are Brown Black Silver Gold ( 0.1 ohm) The other 4 are Orange Brown Brown Gold ( 310 ohm ) ... I think ... The 2nd color band is very oddly faded on all 4 on my brd. Would have to remove one to make absolutely sure. After seeing another reply post on this subject ... it seems that they are 330 hohmers ... my 2nd color band(s) were quite unclear as to whether it was orange or brown ... so glad we could clear that up On another note does anyone actually have a schematic for the RT-12D PS/Amp ??? PS >>> Glad I found this Forum !!! Edited December 22, 2020 by Journey Quote Link to comment Share on other sites More sharing options...
Journey Posted December 22, 2020 Share Posted December 22, 2020 Hi All Again ... Getting into more detail of my repair job on this RT-12D unit ... so far I have not been able find a damned thing wrong ANYWHERE ! I have checked for shorts and found none ... All diodes and transistors check out good as well ... no broken solder joints ... speaking on broken solder joints, in my experience on fixing subs ... a lot of them tend to shake themselves to death so one tends to end up looking for broken solder or main filter cap leads for the PS are broken or even in one case the internal guts of a cap were broken up. Saw this over and over with a set of Mackie subs I was constantly repairing when I was the house soundman. continuing ... ... removed the control board for the primary side and all components test good although I have no idea how check if the the half bridge driver is ok once the circuit is removed. Not sure from reading here what tends to go wrong with the control board. Did a really good going over of the amp brd and so far no issues there either. I'm almost out of ideas on this one at this point. I removed all and any glue that may have been causing an issue as well. I'm wondering if the brd with the DSP circuitry might be sending or receiving a protection shut down signal to the PS ? A schematic for this unit would sure help but so far it's been USE THE FORCE LUKE approach. I found a scheme for a different unit which is fairly similar BUT ... it's the RW-12 so the PS is somewhat different. Any ideas or help would be appreciated ... Journey Quote Link to comment Share on other sites More sharing options...
ngen33r Posted December 22, 2020 Author Share Posted December 22, 2020 RECAP & repair the control board. No schematics are known to exist for these. Quote Link to comment Share on other sites More sharing options...
Journey Posted December 23, 2020 Share Posted December 23, 2020 (edited) Hi Wayne ... Just placed my order with Digikey for a full recap and also the 4 330ohm resistors for the amp brd. I finally found the problem ... when I was removing components to get all that nasty glue removed. C2 and C51 ... those 2 105K 250 volt film caps on the primary side were in pretty bad shape. I was only able to see the obvious damage after I got the glue off and removed them from the brd. One cap actually swelled so bad the metal film inside oozed out the bottom and the other had a hole on one side where metal was visible. I hope the control board is still ok as I checked all but the driver IC so I think it may still be ok. So when those two caps go ... have you seen any other components go with them ? So far everything checks out ok ... no shorts ... no bad trannys or diodes ... fingers crossed. Another quick question ... have you done any work on other audio products other than Klipsch ? Duh !!! another quick Q ... For the full recap ... did you replace all the large voltage disk caps as well ? and the small ceramics ? I'm actually totally surprised to see these film caps shot ... never seen one go like this before this job ... in fact never seen one of these ever go bad in any audio equipment before ... very very odd ... maybe the voltage rating on them are too low ? Do you know how to say ENGINEERED OBSOLECENSE ??? Well under-rating a component would be one way to do it to be sure ... eventually it will fail and you just go buy a new box. The same could said for those 330 Homers on the amp brd ... they should been at least 3 or 5 watters for long life on that end of things. Edited December 23, 2020 by Journey Just an addendum for all edits ... Quote Link to comment Share on other sites More sharing options...
Journey Posted December 23, 2020 Share Posted December 23, 2020 (edited) Thought I would post some pix of the damaged caps in question ... Both these damaged caps measured in the very low pF's so were DEFINITELY pooched ... as one can well see Edited December 23, 2020 by Journey Quote Link to comment Share on other sites More sharing options...
Journey Posted December 25, 2020 Share Posted December 25, 2020 (edited) Hello Again ... Well I have an update on my repair job. I recapped all PS brd except for the big disk HV caps and the ceramics as they IMO rarely have issues. I hooked up the power and seemingly nothing happened. So checked the fuse in my Variac ... it blew. ( Note: I am using a 100 watt light bulb trick as current limiter ) Replaced the variac fuse and I saw a wisp of smoke and possibly a very tiny flash/spark ... cannot be sure if it came from the brd or it might have been my variac fuse blowing again. The 1st fuse was 8 amps second was 5 both blew right away ... the 1st power up there was no action on the light bulb ... still not seeing any shorts on the primary side to cause main fuse to blow or light up the bulb ... also 2nd fuse at 5 amp saw no action with the bulb. This is very very odd as the primary is drawing more than 8 amps to blow an 8 amp fuse which IMO would indicate a dead short somewhere in the primary side but none can be found. Again also ... no dead shorts on secondary either as far as I can say at this point. ALL that crappy glue has been removed so not an issue. I did find an odd component with no markings on secondary side ... looks like a diode ... removed it and the pcb reference had two designations so have no idea which one it is. One ref is D8 (off to the right) the other is TH3 (under the component) ... only connections to it on both leads run to the Conn to the amp brd ... pin 2 and pin 8 ... odd thing is no other connections on the main PS brd. It sits just in front of D16 on the far right side of the brd looking down on component side withe the amp conn at far right. On diode test it reads OL both directions ... on ohms it reads close to 150K. I don't think this has anything to do with the issues on the primary side but thot I'd mention it anyway. So I'm back to square one AGAIN ! The obvious damage to C2 and C51(?) the two film caps at 1uF 250V were what I thought was the issue ... that wisp of smoke I saw came from that area ... can't imagine they cooked again as there are no shorts anywhere on the primary ... UNLESS it's the transformer maybe ? Tested the SMPS transformer with a Blue watcha ma call it and seems ok ... If I can't fix this system and we just buy a new complete unit ... I WILL remove all components and draw up a schematic for this BE-ach ! ... at least for the SMPS to start with. I'm hoping Wayne can advise where to go/look next ... any ideas there Mr. Wizard ??? PS>>> I removed all 4 MOSFETS on primary and tested them on a breadbrd circuit and they all tested good ... there was one however that did something odd 1st go round. When I pushed the button to switch the LED on ... it stayed on ... I then had to ground the gate to turn it off. 2nd time around it behaved as all the others ... had to keep pressing the button to activate the gate to turn on LED. And again after recapping and having the fuses blow on my variac still no shorts on the FETS. PSS2>>> Just out curiosity ... how do you redo your VIA'S ??? Is there some kit one can get to do them ? Do you just run jumps ? When I do failed via's I just run a jump thru the old hole and for burnt traces I try to do what you do but also just run jumper wires ... depends on what kind of mood I''m in LOL ! Edited December 25, 2020 by Journey Addendum 2 ... question for Wayne ... Quote Link to comment Share on other sites More sharing options...
ngen33r Posted December 29, 2020 Author Share Posted December 29, 2020 On 12/24/2020 at 7:42 PM, Journey said: Hello Again ... Well I have an update on my repair job. I recapped all PS brd except for the big disk HV caps and the ceramics as they IMO rarely have issues. I hooked up the power and seemingly nothing happened. So checked the fuse in my Variac ... it blew. ( Note: I am using a 100 watt light bulb trick as current limiter ) Replaced the variac fuse and I saw a wisp of smoke and possibly a very tiny flash/spark ... cannot be sure if it came from the brd or it might have been my variac fuse blowing again. The 1st fuse was 8 amps second was 5 both blew right away ... the 1st power up there was no action on the light bulb ... still not seeing any shorts on the primary side to cause main fuse to blow or light up the bulb ... also 2nd fuse at 5 amp saw no action with the bulb. This is very very odd as the primary is drawing more than 8 amps to blow an 8 amp fuse which IMO would indicate a dead short somewhere in the primary side but none can be found. Again also ... no dead shorts on secondary either as far as I can say at this point. ALL that crappy glue has been removed so not an issue. I did find an odd component with no markings on secondary side ... looks like a diode ... removed it and the pcb reference had two designations so have no idea which one it is. One ref is D8 (off to the right) the other is TH3 (under the component) ... only connections to it on both leads run to the Conn to the amp brd ... pin 2 and pin 8 ... odd thing is no other connections on the main PS brd. It sits just in front of D16 on the far right side of the brd looking down on component side withe the amp conn at far right. On diode test it reads OL both directions ... on ohms it reads close to 150K. I don't think this has anything to do with the issues on the primary side but thot I'd mention it anyway. So I'm back to square one AGAIN ! The obvious damage to C2 and C51(?) the two film caps at 1uF 250V were what I thought was the issue ... that wisp of smoke I saw came from that area ... can't imagine they cooked again as there are no shorts anywhere on the primary ... UNLESS it's the transformer maybe ? Tested the SMPS transformer with a Blue watcha ma call it and seems ok ... If I can't fix this system and we just buy a new complete unit ... I WILL remove all components and draw up a schematic for this BE-ach ! ... at least for the SMPS to start with. I'm hoping Wayne can advise where to go/look next ... any ideas there Mr. Wizard ??? PS>>> I removed all 4 MOSFETS on primary and tested them on a breadbrd circuit and they all tested good ... there was one however that did something odd 1st go round. When I pushed the button to switch the LED on ... it stayed on ... I then had to ground the gate to turn it off. 2nd time around it behaved as all the others ... had to keep pressing the button to activate the gate to turn on LED. And again after recapping and having the fuses blow on my variac still no shorts on the FETS. PSS2>>> Just out curiosity ... how do you redo your VIA'S ??? Is there some kit one can get to do them ? Do you just run jumps ? When I do failed via's I just run a jump thru the old hole and for burnt traces I try to do what you do but also just run jumper wires ... depends on what kind of mood I''m in LOL ! An 8A fuse will NOT blow with the bulb in series. Something is wrong in your setup. The most current that can be sourced would be ~1A before the bulb goes full on and clamps the current. I replace the via with a thru hole repair kit. They are VERY expensive for what they are but needed IMO for a professional repair. Quote Link to comment Share on other sites More sharing options...
Journey Posted December 29, 2020 Share Posted December 29, 2020 Well inst that interesting ... I have used my light bulb rig on previous repairs and it worked as it should. I just checked it for error or faults and it checked out exactly as it should. I don't think I anyone could screw this one up. So with no obvious shorts or blown components on he primary ... it's beyond me what would cause my Variac fuse to go with absolutely ZERO activity on the light bulb ... not even a quick dim glow. SO again ... any ideas ? Quote Link to comment Share on other sites More sharing options...
Journey Posted December 30, 2020 Share Posted December 30, 2020 Hi Wayne ... I have undertaken the daunting task of drawing up a schematic for the RT-12 starting with the primary side of the SMPS. I want to be able to incorporate the control board ... I have saved a copy of your schematic from page one of the thread here but the res is just poor enough I can't read the signal names on the connector or where they are in the circuit. Having a better copy would save me much time to complete the 1st section ... I'm about halfway done already. I was hoping you could send me a better copy ... if your ok with that you can email it to me at my gmail junker accnt. journeyslottowizard@gmail.com Thank you in advance Quote Link to comment Share on other sites More sharing options...
Journey Posted January 1, 2021 Share Posted January 1, 2021 (edited) Hi Wayne ... Happy New there my friend ... A couple things of note ... Who did you buy your Via repair kit from ? I have only found one source online so far at a place called Best here .. https://www.solder.net/products/pcb-repair/pcb-repair-kit/ On another note ... as I was drawing up my schematic ... I noticed an odd contradiction. Looking at your research and developement of the control brd schematic and rebuild ... I see that pin 1 is on the left side of the brd looking at component side. When I look at the original orientation of this brd on the main pcb pin 3 is NOT Gnd. So it looks like to me that the ctrl brd is using a negative DC supply ??? I removed the ctrl brd again to check it again for problems after I recapped and saw some smoke and fuses blowing on my variac. II ruined nearly all the vias and pads ... this pcb brd was made very poorly ... which is why I asked about where/who you got your via replacement kit from. But it's the pinout of the ctrl brd compared to the pins on the main PS brd don't make any sense. UNLESS ... the DC supply is negative to this brd. I''l post what I have on the schematic so far soon ... Edited January 1, 2021 by Journey addendum Quote Link to comment Share on other sites More sharing options...
Journey Posted January 1, 2021 Share Posted January 1, 2021 (edited) Here's what I have so far part 1 ... I had to rearrange your schematic for the ctrl brd to work with rest of the thing ... As you can see ... I reduced the size and made all off brd connections to one side of the diagram with the FETS added... feel free to double check for errors ... however you should find none. Edited September 7, 2021 by Journey minor correction ... missing wire from Q4 pin 2 to D5 and R8 Quote Link to comment Share on other sites More sharing options...
Journey Posted January 1, 2021 Share Posted January 1, 2021 Rest of schematic .... As far as the transformer goes ... it's my best guess as far as how the windings go .... but I think it's perdy damed close. Still working to get the rest done ... Quote Link to comment Share on other sites More sharing options...
Journey Posted January 2, 2021 Share Posted January 2, 2021 (edited) I finished the schematic for the primary side ... I'm pretty sure I got it all with no errors however ... it would be nice if someone double checked my work. I believe I had one error in my 1st post of the main brd which is now corrected ... it was in the R5 area ... Edited January 2, 2021 by Journey Added anothe note Quote Link to comment Share on other sites More sharing options...
Journey Posted January 3, 2021 Share Posted January 3, 2021 So well on my way doing up the secondary side of the PS ... will be posting when done. Quote Link to comment Share on other sites More sharing options...
ngen33r Posted January 6, 2021 Author Share Posted January 6, 2021 On 1/2/2021 at 8:10 PM, Journey said: So well on my way doing up the secondary side of the PS ... will be posting when done. This is looking great. I have done this in the past, but I never had the time to fully invest into making the schematics. Are you using Eagle or Kicad? I can just upload the schematic file for you. Quote Link to comment Share on other sites More sharing options...
Journey Posted January 7, 2021 Share Posted January 7, 2021 (edited) Hi Wayne ... I am using KiCad ... but on occasion I will use OrCad 9.2 which I luckily got a copy of from my old job at Creation Tech. If I use OrCad I can't do pcb layouts tho whereas with KiCad I can do both. As regards the schematic upload that would be great as long as it's a high res image. The one on the 1st page of this thread is unreadable where the input/output pin labels are needed. With a more readable version I can goo back and recheck my work I ended up removing the control brd again anyway to check it again for problems ... and unfortunately this pcb manufacture is so piss poor most of the pads and all of the vias are toast. So looking at running lots of jumpers ... also still no faults found on round 2 of the control brd check. I thought when I saw a very very tiny wisp of smoke when I powered up again with a new fuse ... (5amp) it kinda came from the ctrl brd area which is why I decided to remove it one more time and that was it for the via's and pads. It also could have come from the Variac when the fuse popped. So with the ctrl brd removed I was able to get the primary side finished up just tracing the ctrl pinouts to respective paths. I was wondering about the Half Bridge driver on that brd and if it's failed ... would that cause the 4 fets to remain on and this is why my fuses are blowing ? I'm thinking that if this was the case I would be losing a fet or two in the process .. ya no ??? Think I might just put new FET's anyway even tho they all tested good on my breadbrd test jig. Probably will replace the IR2153 as well ... cheap parts ... You may have noticed ... I rearranged your ctrl brd schematic to fit better with the main brd making it easily readable easy to follow. Hope you don't mind ... might be good idea for a second set of eyes to make sure it is still correct. Making my way into the secondary ... it's looking like it will be a long slog without removing many if not all components but I'll give it my best shot. I'll check back again here soon ... G"day Edited January 7, 2021 by Journey mis-spellings and additions Quote Link to comment Share on other sites More sharing options...
Journey Posted January 8, 2021 Share Posted January 8, 2021 Just out of curiosity ... have you a way that you test the ctrl brd when it's out of circuit ? I saw in one video where I saw a ctrl brd out but there were still wires connecting it in circuit. Does it have to be actually in circuit to take voltage measurement or scope the switching signal ? Quote Link to comment Share on other sites More sharing options...
ngen33r Posted January 11, 2021 Author Share Posted January 11, 2021 On 1/7/2021 at 10:09 PM, Journey said: Just out of curiosity ... have you a way that you test the ctrl brd when it's out of circuit ? I saw in one video where I saw a ctrl brd out but there were still wires connecting it in circuit. Does it have to be actually in circuit to take voltage measurement or scope the switching signal ? I have not made any test fixtures. I keep a spare power supply that is known good and use that as a test rig. You can always socket the components for testing then remove the sockets for final install. I have attached my version of the schematic. 660045-1.sch 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted January 11, 2021 Share Posted January 11, 2021 3 minutes ago, ngen33r said: I have not made any test fixtures. I keep a spare power supply that is known good and use that as a test rig. You can always socket the components for testing then remove the sockets for final install. I have attached my version of the schematic. 660045-1.sch 17.91 kB · 0 downloads thanks 1 Quote Link to comment Share on other sites More sharing options...
Journey Posted January 20, 2021 Share Posted January 20, 2021 HI guys ... thanks for the schematics posted ... I have rebuilt the control board as far as all the semi-conductors go ... resoldered all smt resistors ... not sure if a guy really needs to do the ceramic caps ... they rarely fail in my experience. As far as I can see so far with the schematic is that I'm 99% sure I got it right when I did my whole primary side schematic where the pinouts are concerned for the ctrl brd. I'm still stumped as all hell as to why this PS is blowing my variac fuses. I was wondering if the ctrl brd is not functioning properly ... would it cause the FETS to stay on all the time and this would or should blow my variac fuse ... but I would also think it should or would take out at least 1 or 2 fets as well ... any thoughts out there ? 1 Quote Link to comment Share on other sites More sharing options...
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