Loud Hum From My Polk Audio PSW140

reaper996 · 12th January 2010, 10:17 PM

Hooking up my Polk Audio PSW140 subwoofer to my stereo this weekend I noticed that the SW would not power up. I pulled the amp plate and found a blown fuse, which I replaced and re-installed the amp plate. Upon plugging it in the SW began to make a loud hum.

I spoke with Tech Support at Polk Audio and they said it might be a regulator or output.

Any ideas what the problem might be or where to start troubleshooting?

Thanks in advance.

DSP_Geek · 13th January 2010, 12:33 AM

I would look at the power supply filter caps. Polk had a problem with underrated caps once upon a time, so they'd blow after a while. On the other hand, you might also want to look at the output transistors:

Bad amp - PSW140 - Club Polk

reaper996 · 17th January 2010, 08:14 PM

I have found the problem, it looks like one of the transistors and two of the resistors got damaged. The transistor looks like a TIP29C, and the tan-bodied resistor looks to have a 10 kohm value and the green-bodied resistor value I cannot determine. When I MM each of the resistors, I get the following values:

tan-bodied 1.828 kohms
green-bodied 2.494 kohms

The two similar, looking, resistors in front of the TIP30C transistor have the following values:

tan-bodied 1 ohm
green-bodied 12 ohms

Not sure what I have going on here.

DSC05889.JPG

DSC05906.JPG

12th January 2010, 10:17 PM	#1
reaper996 diyAudio Member Join Date: May 2009 Location: Northern Virginia	Loud Hum From My Polk Audio PSW140 Hooking up my Polk Audio PSW140 subwoofer to my stereo this weekend I noticed that the SW would not power up. I pulled the amp plate and found a blown fuse, which I replaced and re-installed the amp plate. Upon plugging it in the SW began to make a loud hum. I spoke with Tech Support at Polk Audio and they said it might be a regulator or output. Any ideas what the problem might be or where to start troubleshooting? Thanks in advance.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
broken sub, loud hum	tekkas	Solid State	9	25th January 2009 02:59 AM
VERY loud hum issue	5th element	Solid State	23	30th May 2004 05:37 AM
my amp makes a loud hum	wonder_b	Solid State	5	27th May 2004 10:50 AM
Loud hum problem	gasjack	Chip Amps	4	19th February 2004 12:16 PM
For those who have hum with theyr gainclone (loud or not)	Bricolo	Chip Amps	6	16th July 2003 07:57 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

13th January 2010, 12:33 AM	#2
DSP_Geek diyAudio Member Join Date: Aug 2003 Location: Santa Cruz, California	I would look at the power supply filter caps. Polk had a problem with underrated caps once upon a time, so they'd blow after a while. On the other hand, you might also want to look at the output transistors: Bad amp - PSW140 - Club Polk

17th January 2010, 08:14 PM	#3
reaper996 diyAudio Member Join Date: May 2009 Location: Northern Virginia	I have found the problem, it looks like one of the transistors and two of the resistors got damaged. The transistor looks like a TIP29C, and the tan-bodied resistor looks to have a 10 kohm value and the green-bodied resistor value I cannot determine. When I MM each of the resistors, I get the following values: tan-bodied 1.828 kohms green-bodied 2.494 kohms The two similar, looking, resistors in front of the TIP30C transistor have the following values: tan-bodied 1 ohm green-bodied 12 ohms Not sure what I have going on here. DSC05889.JPG DSC05906.JPG

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)