Amplifier problem

[bigjd73 10+ year member]

I recently installed a refurbished Clif Designs CD40.4LX (crap, I know) in my car and have apparently blown it. It was working fine for about two days and then today it blew 2 of its 3 30A fuses while playing. I replaced the fuses and upon reconnecting the negative battery terminal the fuses blew again. I then disconnected all speaker leads and RCAs from the amp, replaced the fuses again and upon reconnecting the neg battery terminal the fuses didn't blow, but instead the amp started billowing out smoke so I had to run and disconnect the battery.

The amp is obviously now fried and has a nice burnt smell and burn marks on the heat sink near the power supply. I have a few questions on possible causes and to help prevent this with future amps.

What things could've caused this? I was running ID CX65CS of channels 1 & 2 and an Elemental Designs 9kv.2 in infinite baffle bridged on channels 3/4. The sub was a dual 2 and was wired in series so the amp was seeing a 4ohm load. It (supposedly) can handle a 2ohm bridged load so I don't think that was an issue.

Could a shorted VC on the sub have cause the amp to trip the fuses? Sub was running fine before this and running it infinite baffle I was extremely careful with the gains and probably had it set too low even.

Could a bad ground cause the power supply to fry? I think the ground was ok since it was running fine before and had no heat or dimming issues but just want to be sure so as not to destroy my next amp.

Just a bad amp/power supply? Or what else should I look out for?

Thanks for your help.

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[Side Show 10+ year member]

what size inline fuse did you have?

or did you have one?

 

[bigjd73 10+ year member]

100 amp inline fuse, 3 30A fuses on the amp. 2 of the 3 fuses on the amp were the ones that would blow. The 100A inline is still fine.

 

[bigjd73 10+ year member]

Any ideas?

 

[Grinder1989 5,000+ posts]

Low voltage and abuse are the top two reason. Two low of an ohm load is possible as well.

 

[Qbenjamin 10+ year member]

Low voltage and abuse are the top two reason. Two low of an ohm load is possible as well.

Ohm load would be my guess also, although you normally get a few seconds of playing time before the amp blows the internal fuses.

 

[murilo 10+ year member]

Sometimes some power supply burn alone, with no apparent reason.

The power supply works like this: