AMp in protection problem

[mechanic021]

hey guys I have an older 4 channel 400 watt pioneer amp that used to work just fine up until today. I had it in my blazer then took it out for about 2 months. Well today I hooked t up in my pickup truck and it wont come out of protection. I checked all wiring and found it to be ok . I checked every fuse I could find. I even took the cover off and looked inside. IT had no fuses in it but I noticed there was alot of this yellowish goo looking stuff on the board by some little round cylinders. Could something in the amp have puked on me? What alll else should I check on the amp?

 

[JTX]

Chack how many volts are getting to the amp. If the wire isnt grounding good enough that will do it.

 

[mechanic021]

I just checked with meter, I am getting a good ground and supplying alittle over 13 volts with the truck at idle. hmmm

 

[mechanic021]

how often do amps go bad? this is a good 4 years old but still.

 

[JTX]

not to sure, I dunno what would cause that.

 

[Longjohn119]

Were they electrolytic capacitors? (If the board is silkscreened in may say C1, C21, etc next to them) ... Sounds to my like the switchmode/DC-DC converter (Power supply) toasted on it ... In order to get over 25 watts into 4 ohms amps have to have a supply voltage well over 12 volts and usually need it bi-polar (Like +45v and -45v), inside every amp of any wattage there is a DC-DC switchmode converter to raise and split the voltage and they are usually the weakest part of an autosound amp ... In your case I'd say the electrolytic caps dried up do to environmental extremes and shorted the power supply ,,,, it goes and the protection shuts down the amp to protect the outputs ... sometimes they blows anyway ...

Either way it doesn't sound good and you'll have to repair or replace ....