QX1-3000d making humming noise

[1970cuda 10+ year member]

just got a kole audio qx1 3000d that is making a humming sound through my sub with no musical sound at all, not even a bump when i plug in the rca cables and protectoin light is not on either.

i took off the back panel for inspection and noticed that unplugging the cooling fan motor stopped

the humming but i could then hear a higher pitch noise coming from from somewhere in the middle of the board. i also noticed that the plastic covers on three of the five biggest capacitors(80V 2200uf)

looked kind of melted on top and slightly greyish and were also bigger from expansion to the point that it tore through the plastic. when hooked up to power two of the three caps stay cold and the other one starts to get warm just sitting there with no subs attached. the group of largest mosfets

also get pretty hot with zero current draw from subs. there is no burnt smell like when an amp is

destroyed but an electrical smell is present and ive searched the entire board five times and found

no hint of malfunction other than the strange looking caps.

if anyone else has had this problem and knows how to fix it or is good with electronics please share. any opinions?

Click to read more...

 

[DaveVT 10+ year member]

Have the caps replaced before you burn it up.

 

[1970cuda 10+ year member]

well from my understanding the reason most of these amps fry thier caps is from insuficient power and ground wire size due to the 4g mounts on the amp wich causes them to short out or something. so bigger power cable is a definite and maybe upgrade caps from 80v to 100v also,

but is there anything else that could be causing the caps to blow out on these amps? i only ask because a search on the net revealed several other people with this amp who had the same problem(blown caps). maybe there is some other part of the amp witch could also due with an upgrade?

 

[DaveVT 10+ year member]

If the caps are blowing its generally due to age or they are being charged higher than their rated for which im thinking would be a power supply issue.

 

[1970cuda 10+ year member]

well i replaced the blown caps today and every thing looked good. sodder was clean and uniform and caps were firmly in place.

used 4g cable 10'' from battery first with 30 amp fuse and then a 50. the 30 amp fuse was fine until the amp was turned on witch blew it out.

the 50 amp fuse did fine and did not blow but instead three of the mosfets exploded one after the other.wtf does this mean. i replaced the

capacitors with the exact same rated caps and soddered them in perfectly. is this amp a piece of **** or what. by the way amp was free

and its not exactly a M3a(witch i would never try to repair myself) so its not the end of the world if its well done toast.

 

[DaveVT 10+ year member]

Sounds like its not regulating power properly. If you have money to spare id just get a decent amp and junk this one. Its probably not worth the cost of repair.