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ngen33r

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Edit: It seems this is actually C32. I see that value from a previous post. Thanks for all the info; I'll update this post if needed.

 

Hello ngen33r,

   I have acquired a failed Sub-10 amp and rebuilt the PDC, recapped it, and replaced the FETs. It kept blowing the FETs, though, and measuring the output from the PDC to the FET gate it was 114V, so I figured something must've went wrong with the PDC rebuild. The PDC board was pretty crispy, so I fashioned a new one.  Now the power supply seems to be working, the fuse is not blowing, but still no output and no blue LED light. I was testing voltages and suddenly C12 went up in smoke. Do you know what the uF value of C12 is?

IMG_20200809_074108305_Markedup.jpg

Edited by Dr_Vince
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  • 2 weeks later...

Thanks again for the great info here. I was finally able to rescue the Sub-10 I bought. The guy before me had trashed the through holes for the FETs and the AC -DC diode bridge. Then I proceeded to trash the through holes for much of the PDC board, since I myself do not have the proper tools either... Anyway, after days of tracking down and repairing damage to the boards, and making a new PDC board, with integrated gate drive resistors, she's up and running with an upgraded Q5 and new Nichicon audio grade caps.

IMG_20200808_220429434.jpg

IMG_20200813_173905421.jpg

Edited by Dr_Vince
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  • 1 month later...

Hello all. I have a Sub 10 does not power on at all. I'd like to get it repaired. I'm generally okay at finding minor issues but this is more than I want to research and sort on my own. Anyone out there up to tackle this for me? Disassembled and ready to ship.

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  • 4 weeks later...
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Welcome

 

Very well could be, unless abused it's usually the amp that goes out. If abused the driver will go out, if you still want it you could get an outboard amp (regular amp) like Crown or any other. Drill a tiny hole for regular speaker wire or remove the plate amp on the sub and run the wire under the edge and your back in business. A stand alone amp is much more reliable than a sub plate amp usually. Disconnect the plate amp but leave it there to fill the space, the sub was designed to have that area filled as to not change the internal size of the cabinet.

 

.

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On 10/31/2020 at 5:21 PM, Allan B said:

I have a RPW10 that the local repair shop said the sub amp is NFG and needs replacement but they cant find any parts.

Is this correct or is it a case of trying to just sell me a new one.

Please and thank hyou.

Allan

 

 

These amps are always fixable even if almost destroyed. 

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  • 1 month later...
On 7/28/2020 at 9:42 AM, ngen33r said:

 

There is no parts list.

TH3 is a DSP104

10ohm 4A inrush limiter.

 

I am also having trouble finding parts and following this thread.  

 

I have compiled the fragments of information and I am attempting to build a straight forward list of components that are often abbreviated with "Amp was recapped, replaced TH3, FETs, and Q5"

 

"amp was fully recapped with Nichicon caps"  We now have a suggested manufacturer, Can we get a list of the caps and values?

"I use GE silicone 2". Good to know, will add that to materials list

"I had to clean and rebuild the PDC"  Ok, what did that entail?  Parts list please?

"replace the fets".  Can we get a list of PNs?

"and TH3".  OK, back to the original problem.  Where does one find a "TH3"?  Do we have a manufacturer and part number?

 

Suggested Parts list with links:

1) Q5 is SOT-23, it needs to be replaced with a TO-92 2N44011

2) TH3 (DSP104) replaced with ????

3) PDC parts for rebuild. What is all involved in a PDC rebuild? Parts??

4) FETs replaced with ???

5) GE Silicone 2 

 

If you can help fill in the blanks I can edit this post and include links for the parts.

 

 

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  • 2 weeks later...
On 12/10/2020 at 10:14 AM, Kiowa said:

 

I am also having trouble finding parts and following this thread.  

 

I have compiled the fragments of information and I am attempting to build a straight forward list of components that are often abbreviated with "Amp was recapped, replaced TH3, FETs, and Q5"

 

"amp was fully recapped with Nichicon caps"  We now have a suggested manufacturer, Can we get a list of the caps and values?

"I use GE silicone 2". Good to know, will add that to materials list

"I had to clean and rebuild the PDC"  Ok, what did that entail?  Parts list please?

"replace the fets".  Can we get a list of PNs?

"and TH3".  OK, back to the original problem.  Where does one find a "TH3"?  Do we have a manufacturer and part number?

 

Suggested Parts list with links:

1) Q5 is SOT-23, it needs to be replaced with a TO-92 2N44011

2) TH3 (DSP104) replaced with ????

3) PDC parts for rebuild. What is all involved in a PDC rebuild? Parts??

4) FETs replaced with ???

5) GE Silicone 2 

 

If you can help fill in the blanks I can edit this post and include links for the parts.

 

 

 

 

 

 

DO NOT BUY PARTS FROM AMAZON, DON'T DO IT!
https://www.digikey.com/en/products/detail/on-semiconductor/2N4401BU/1417

 

https://www.digikey.com/en/products/detail/epcos-tdk-electronics/B57211P0100M301/2781797

 

PDC parts are listed on the schematic I made and posted. Rebuild requires replacing what is bad and what PDC you have. There are 2 different versions with different parts.

FETS are IRF730/740 depending on the amp you have

Everything is available on DigiKey or Mouser, or any reputable parts supplier.

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  • 2 weeks later...

Sub-10:

 

After a full recap, MOSFET, THC, Q5, Z1, and TH3 replacement I went to test the PSU via your video @59:00. I am only seeing 20VDC. I have removed the yellow glue from any visible parts that it could cause a short between.

 

My current limited AC supply bulb is pulsing bright/dim.

 

Also, I see very little voltage between R70 and R71 as you tested @59:43. From this forum I believe you are saying the issue is the BASH board or PDC.

 

What would cause the +15V_M and -15V_M at (U4 Pin3 & U5 Pin3) to be limited to 20VDC instead of 25-30VDC and is this acceptable?

 

I removed the PDC and BASH boards and I no longer see a pulsing bulb on my AC limited supply. 

 

How do I troubleshoot these two boards to determine where the fault is? 

 

The DB1 BASH3010A IC on the BASH board.  If that is faulty, where can I find a replacement chip?

 

I plan to put a single row female socket 8P and 12P header on the board so that I can more easily remove the PDC and BASH sub-boards for troubleshooting until I can figure out where the problem exists.

IMG_001.JPG

IMG_003.JPG

Edited by Kiowa
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  • 2 weeks later...

With the PDC removed I get 150V out of the D6 rectifier so that portion of the PSU is working now that the inrush limiter has been replaced.

 

 I did a full rebuild of the PDC with the schematic and parts listed in this thread.  When I measure across the body of U4 and U5 according to your video I should see ~30V.  I am only seeing 2.5 volts (with a lot of wild variation on the meter) and my AC limited supply bulb is pulsing bring/dim.  Do you have any suggestions on how to better validate operation or troubleshoot the PDC board?

 

here is a quick video:

Video

 

Update (even thought it looks like this thread is pretty much dead):

The problem was having the BASH board removed during testing let the Gate Drive that feeds Q7 float and damaged Q7.  I also noticed Q14 was shorted as well (Both had been replaced during my rebuild once already).

 

Removing both Q7 and Q14 (both IRF530).  Then replacing Q7, puts the amp in working condition from a power supply perspective.  No more pulsing AC bulb.  I see ~22VDC across the body of U4 and U5.  I see the 5VDC across R70 and R71.  Everything looks good.  I verified the BASH board is getting 15VDC as well. 

 

Problem:

The problem is when I populate Q14 (IRF530) the flashing AC limiter bulb is back and the board is unhappy again.  Not sure what to troubleshoot on the Q14 side.  The PDC and BASH seem to be working to me.  Would this be an indicator of a bad U3 opamp? 

 

 

Thanks

Edited by Kiowa
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On 1/9/2021 at 8:00 PM, Kiowa said:

With the PDC removed I get 150V out of the D6 rectifier so that portion of the PSU is working now that the inrush limiter has been replaced.

 

 I did a full rebuild of the PDC with the schematic and parts listed in this thread.  When I measure across the body of U4 and U5 according to your video I should see ~30V.  I am only seeing 2.5 volts (with a lot of wild variation on the meter) and my AC limited supply bulb is pulsing bring/dim.  Do you have any suggestions on how to better validate operation or troubleshoot the PDC board?

 

here is a quick video:

Video

 

Update (even thought it looks like this thread is pretty much dead):

The problem was having the BASH board removed during testing let the Gate Drive that feeds Q7 float and damaged Q7.  I also noticed Q14 was shorted as well (Both had been replaced during my rebuild once already).

 

Removing both Q7 and Q14 (both IRF530).  Then replacing Q7, puts the amp in working condition from a power supply perspective.  No more pulsing AC bulb.  I see ~22VDC across the body of U4 and U5.  I see the 5VDC across R70 and R71.  Everything looks good.  I verified the BASH board is getting 15VDC as well. 

 

Problem:

The problem is when I populate Q14 (IRF530) the flashing AC limiter bulb is back and the board is unhappy again.  Not sure what to troubleshoot on the Q14 side.  The PDC and BASH seem to be working to me.  Would this be an indicator of a bad U3 opamp? 

 

 

Thanks

 

The BIAS could be way off or the volume is too high. Testing should always happen with the volume at 5% or less. If the outputs were replaced the pots will need to be adjusted. I plan to cover this in a future video.

 

The unmarked DIAC is a DB6 and can be sourced from NTE.

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19 hours ago, ngen33r said:

 

The BIAS could be way off or the volume is too high. Testing should always happen with the volume at 5% or less. If the outputs were replaced the pots will need to be adjusted. I plan to cover this in a future video.

 

The unmarked DIAC is a DB6 and can be sourced from NTE.

I found the issue.  When I replaced the MOSFETs I attempted to read the part numbers off of the parts removed and replace with the same parts.  I got the Q13 and Q19 wrong.  Instead I replaced with the following and all is working now:  Q14,Q20,Q7=IRF530 and Q13,Q19=IRF9Z14 or IRF9530.

 

Like to see the pot tuning video.  I don't have an expensive set of 8ohm resistors to sink the amp into.  Can you cover tuning with conventional setup just using the speaker connected?

Edited by Kiowa
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Hi ngen33r,
I have a sub12 with a dead amp that I'd love to just buy a replacement for.
Would you happen to sell refurbished amps? -or- would you happen to have a source for this?
I'm confident enough to unhook and replace the amp but not much more than that.

 

Thank you,

vigileric@hotmail.com

Eric Vigil

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