RW12D Sub has display but puts out no sound

[BillAustin]

I have an RW 12D sub the display is "ON" but the unit will not put sound out.  I verified in the receiver menus the sub is setup and should be pushing sound.   I pulled my small 8" sub from another room to verify the cable and sub setup is working and I get sound from 8" sub no problem but when the RW 12D is hooked up I have no sound but I do see the display window is active and on. 

 

I even took the RW12D to the other room and hooked it up to that other system where I pulled the 8" sub from - just to try it and got no sound via that setup either.

 

I don't see a fuse on the back panel that I could check or change, so I pulled the back board but still didn't see any sort of fuse to check or replace, (I could be missing it) - I unplugged it and let it sit a few hours but no luck when plugging it back in, is there anything I can check or do?  I don't see anything on this board that looks burnt worn or a fuse that I can see/tell or change.  

 

Confused and bummed (since i rarely even have this sub plugged in or on).

[wuzzzer]

https://community.klipsch.com/index.php?/topic/187558-rw-10-rw-10d-rw-12-rw-12d-repair-blog/

[captainbeefheart]

The bottom right of your picture you posted you will see red and black wires running from the flat power supply board over to the vertically mounted amplifier board. Measure DC voltage here, either black to red and or both red and black in respect to ground as these are +/- rails.

 

You should see something like:

 

Red to black = 50v

 

Red to ground = +25v

 

Black to ground = -25v

 

This will determine if the power supply board is bad which is very common with these and many subwoofers with switch mode power supplies. I still use an older Sub with a honkin big power transformer for a linear supply because they are just so much more reliable and simpler to repair.

 

[babadono]

11 hours ago, captainbeefheart said:

This will determine if the power supply board is bad which is very common with these and many OTHER KLIPSCH subwoofers with switch mode power supplies

Fixed it fer ya

[captainbeefheart]

1 hour ago, babadono said:

Fixed it fer ya

 

Indeed a huge problem for Klipsch sub-woofer's which is why I keep my older linear power supply with full complimentary Class AB output stage. Yes it is heavy but more reliable and easy to repair.

 

 

I am new here but reading through there seems to be a guy that takes care of these for everyone? They must just send him the plate amp section in the mail. He must have more work than he knows what to do with 🤣 

 

If anyone is in the North East, specifically the Boston area feel free to private message me and I don't mind helping out.  I have a Day job that puts food on the table but I do help friends and anyone in word of mouth shot (friends of friends etc..) with repairing or modding gear. I have been told many times that there is great demand for good techs, especially ones that just don't follow schematics with basic skills but with actual engineering experience. Tube amplifier interest has gone through the roof and I get asked a lot to help a friend of a friend with a tube amp they purchased from China. These have flooded the market because of the price but they are not really good designs and many have errors and or fail often. With minimal effort these can be made into great amplifiers and contrary to belief you do not need to replace the output transformers, they can actually perform quite well with some control theory knowledge and get great square wave response at extended bandwidth. Ahh the wonders of proper application of feedback and increasing phase margin. I like my day job to stay there but I love this hobby enough to bring happiness to anyone that is passionate about music and their gear.

 

I elected to help my friend in Maine with an Audio Matre Equilibre amplifier that is known for blowing the power transformer. I have done a few of these now and it is tough getting the old power transformer out of the enclosure and potting a new replacement in there. The problem was many didn't have a soft start and with so much capacitance in the power supply they just smoke the HV windings. Funny, they put these potted "magic box" components that are told makes the magic of these amps do what they do. Well I tested to see what it did and well it didn't do anything, even cut it open and viola snake oil, it just connects the two types of output tubes that in parallel (triode || pentode) and what has been done since the 50's called "extended Class A" amplifier, well that was the earliest article I found on the topology. I am surprised other companies have not adopted this topology as they actually do sound very good.