Thermal Overload

STRino

Have a Polk MOMO MM2154 sub, driven by a MOMO C300.2 amp in bridged mode. I wasn't playing it especially loud - I was breaking the sub in - and the amp popped. It doesn't send a signal to any channels.

The Thermal Overload LED never went on - but is there a way to check that it didn't go thermal? The amp is brand new - and played for two hours before it popped.

I bought all my stuff from Crutchfield, and Crutchfield is saying that the amp is a discontinued model. They'll swap the C300.2 for a Kenwood KAC7202. Not an option I want to take -- I am building an all POLK system... and don't want to even hear the word Kenwood. :rolleyes:


Any way to check the amp if it went thermal? It hasn't worked since Saturday - although it does power up with my deck.

neomagus00

if the amp lights up, i'm going to venture a guess that it could be your sub, just as a guess. to check, take your multimeter (you have a multimeter, right?) and measure the resistance across the sub. it should be in the 2-4 ohm range. if you get something like 50 or infinity, it's the sub. if you don't have a multimeter, take a 9V battery and briefly tap it against the terminals of the sub - it should 'pop', move a bit, in which case it's NOT the sub.

other than that, i've got no idea, cept i'm fairly sure the 300.2 is not discontinued...

p.s. this assumes you've already checked all your connections, RCAs, speaker wire, everything (on both ends of all cables)... that'd be a good place to start, your RCA could have just pulled loose

exalted512

if its not working, who says you have to send it back to crutchfield? send it straight to polk, theyll take care of you
-Cody

MacLeod

Originally posted by exalted512
if its not working, who says you have to send it back to crutchfield? send it straight to polk, theyll take care of you
-Cody

Thats what I was about to say. Since you did it the smart way and bought from an authorized dealer, you can enjoy full support from the finest customer service dept in the industry. Give em a call.

Im assuming the power light is not on? If not then you can also check your power and remote wires to make sure theyre hot when turned on. Use either a multimeter or go to Autozone and buy a $5 test light. If all those check out then check the ground.

STRino

This is the second C300.2 amp in three weeks and I'm not very pleased. The amp isn't under powered for this sub - as the sub's working range is 75W - 400W -- with a peak of 800W. The amp is 550W @ 1 channel bridged - with 850W peak power. So, as you can see -- the specs are all in line. The amp can hit harder than the sub - if needed.

If it went thermal -- is there an internal reset? How do I get to it?

The second amp was working fine for roughly 3 hours -- and then the sub suddenly stopped working. I checked the fuse under the hood and at the amp. Both of them are fine. I've tested the sub in another vehicle and it works great. I've also tested a second amp to my wiring -- and the Alpine V12 I tested worked great too!


I'm starting to think that Polk maybe wasn't the best choice of audio.... please tell me that I'm just over reacting.


I'm getting tired of this....

aaharvel

maybe you should try Alpine? They've always been what I used- always thought they were the best but my alphine car gear is like 5 years old and I don't presently keep up with car audio- so it's just a suggestion..

exalted512

Maybe its the install

neomagus00

i've had a 300.2 for about 2 years now and it's performed absolutely flawlessly for me.

have you checked the wiring yourself, to make absolutely sure it's not that? it's quite easy and can save everyone a lot of hassle and anger if we're all sure it's not something that simple. specifically, make sure there're no cuts in the insulation for the power and ground wires. make sure the hole where the power line goes from the engine bay to the passenger compartment isn't cutting the power line. make sure the ground is clamped firmly on to bare metal. make sure the power and ground cables don't have any threads touching each other or the amp case where they both screw into the amp - this caused me grief once. check all the fuses in the audio line again, just to be very very sure. that's all you're doing, making sure you covered all your bases.

barring that, how bout you pop the cover off the amp and do a visual inspection - is anything obviously not right? especially check out the big black boxes with three wires apiece (i'm assuming you're not an electronics guy, correct me if i'm wrong).

exalted512

Originally posted by neomagus00

barring that, how bout you pop the cover off the amp and do a visual inspection - is anything obviously not right? especially check out the big black boxes with three wires apiece (i'm assuming you're not an electronics guy, correct me if i'm wrong).

this voids the warranty correct?

neomagus00

it shouldn't, no, that's the only way to get to the subsonic jumper... it'd be pretty unfair if that voided your warranty... lemme call polk...

EDIT: nope, they say it's just fine

exalted512

thats cool, most companies are dicks about that kind of stuff
-Cody