CurtPalme.com Home Theater Forum

Chuck27 · Posted: Tue Jan 08, 2008 1:52 pm Post subject: Transistor Replacement

I have several Polk PSW200 amps that I use for subwoofers, couch shaking devices, etc.

Recently, while "testing" one of the amps, I managed to cook it (gee, I wonder how that happened?).

I took it apart (such as it is) and found one of the power transistors was broken and charred so I'm going to guess that's what I smelled burning.

I admit to being somewhat ham-fisted when it comes to repairing electronics, but this actually looks like something I could fix by de-soldering the old one and replacing it.

The transistor in question is described as "P-channel enhancement-mode power field-effect transistor", it is part number RFP10P12 and is in a TO-220AB case.

I've been trying to locate a retailer of such a device and the closest I've come is a grab-bag from what used to be Radio Shack.

I have two questions:

1. Does anyone know of a retailer where I might get a couple of these transistors?

2. Is there a more readily-available but different transistor in the same case that I can substitute, confident it will perform the intended function?

Thanks for the help, folks....

Chuck

**Curt Palme** · Posted: Tue Jan 08, 2008 1:59 pm Post subject:

That's a MOSFET.

http://www.chipdocs.com/datasheets/datasheet-pdf/GESS/RFM10P12.html

Change ALL of the MOSFETS as I'll bet the others are damaged, and usually a short like that will backfire into the driver stages of the unit. This is probably best left for a tech.

Chuck27 · Posted: Tue Jan 08, 2008 2:29 pm Post subject:

Thanks, Curt. I did notice another device with the same markings alongside, and they were both up against the heat sink so it was my plan to replace both once I can locate the parts.

This amp doesn't owe me anything and I have very little invested in it, so it would be more for my own personal thrill of actually having repaired a piece of electronics than anything else, which is why I wanted to try it myself.

Chuck

WTS · Joined: 08 Mar 2006 Posts: 1276 Location: Calgary

HI Chuck,

That looks like an old old RCA part number, you could try a SPP15P10P G made by Infineon Technologies. Digikey has them in stock for about $2.oo each.

Chuck27 · Posted: Tue Jan 08, 2008 6:14 pm Post subject:

That's great, Walter...thanks! I'll give them a try later today.

Chuck

WTS · Joined: 08 Mar 2006 Posts: 1276 Location: Calgary

I can't say if it's a 100% match though.

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

http://www.sierraic.com/pnresults.asp?navpart=RFP10P12

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Also the RFP10P12 cross's to Toshiba 2SJ407. The 2SJ407 then cross's to International Rectifier IRFI9630G available here:

#http://parts.digikey.com/1/parts/1021391-mosfet-p-ch-200v-4-3a-to220fp-irfi9630g.html

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

OK. Looking over the datasheets for those cross's they don't look like a good match. Here is a cross for the original and it even carries more amperage:

http://www.mouser.com/Search/Refine.aspx?Ntt=*rfp10p12*&N=1323038&Ntx=mode%2bmatchall&Ns=P_SField&OriginalKeyword=rfp10p12&Ntk=Mouser_Wildcards

Chuck27 · Posted: Mon Jan 14, 2008 2:11 pm Post subject:

Thanks, Mac. I appreciate the help...I'd have no idea how to cross-reference something like that. It's also nice to find an actual retailer...whenever I found someone with stock, they had a minimum order quantity that was going to make this little project a non-starter.

I've placed the order with Mouser so we will see what happens.

Thanks again...

Chuck