Issue with M&K sub amp

Mohit8994

Hi,

I have an M&K subwoofer amp, which is rated at 250 watts, is from M&K VX1250, a much acclaimed sub of its time. I have it mated to a Dayton 15" subwoofer, and it used to work well until yesterday. The amp basically has a 6 dB bass boost at 30Hz, which I wanted to remove. So, I opened it up, removed the preamp and the amp circuit boards(screws, foam, etc), checked for R26, which my seller had said needed to be replaced to change the boost to a 2db at 21 Hz. I was, fortunately or unfortunately, unable to locate the resistor (though I see it now) and I put all the things back again and plugged power in to see if all was okay. It worked fine, no abnormal sound, no humming, etc, and then after some 2-3 mins, went dead :mad:. There was a little thud, not too loud, when this happenned.

The red light, which glows even when it is off is not glowing now, and nothing on it works. There is no smell of anything burning or anything, would appreciate any help in troubleshooting the amp.

Thanks a ton,
Mohit

wutadumsn23

Welcome to Club Polk Mohit. Fuse maybe??

-Jeff

danz1906

Welcome to the Club!

Mohit8994

Hey Jeff and Danz,

Thanks for the warm welcome

I really hope it is the fuse, but am unable to find it in the amp! Any clue as to where it could be?? It is not in the power cord for sure, and there is small green colored box sort of a thing, looks like a fuse but says .1uf (meaning it is a cap).

I do not have any sophisticated gear with me at the moment, not even a multimeter :rolleyes:

I am not sure of what's wrong with the amp, but in my opinion, even if something is wrong, and if it is not the fuse, shouldn't the red light turn on when the amp is connected to power?

Thanks!

wutadumsn23

If the fuse is blown, I would imagine it would kill power to the whole unit and the little red light would not illuminate. I am not 100% positive on this, and I'm sure someone else has the answer. You seem to know what you are doing, but it may very well be that you shook/jarred something loose when you took it apart, if in fact the fuse is still good. Find that fuse and take it from there, hopefully it is something easy like that.

-Jeff

haltomscri

That was the first thing that came to mind for me as well, but the woofer is run from a plate amp and if he is not getting any bass, it should be a room or signal issue of some sort.

I do agree, that an external amp would help - but in this case, I do not think it will solve his problem.

haltomscri.

dorokusai

Does a light turn on when you plug the amp in a socket? power switch to on?