Amp only works upside down

[jonbarrett]

I know nothing about audio equipment.

While digging around in the passenger footwell I found an amp. Power light said it was dead. However, when I moved it, it powered up and the front speakers started working. Loose wire I thought. On inspection all the wiring was fine. After playing with it for a while I've discovered it only works one way up. Turn it over and it dies, turn it back and it's fine. Strange.

The cover is clear so I can see there is no internal wiring, nothing loose and no mercury switches I can see. Would there be any reason why an amp would need to be 'this way up'.

[alinton]

No reason at all. I would imagine there's some kind of bad connection in there somewhere, maybe even a core in one of the connecting cables broke.

Where was the amp? Does is have +12v power? There's not usually any amplifier for the front speakers, must be an aftermarket addition.

Andy.

[thegreengoblet]

Most are wired to power up from the head unit with a "remote amp switch on" wire. The Amp will still have it's own chunky power cables, but it is this wire that actaully allows the amp to power on or off.

[coey 4.2]

Prob a dry solder joint on the PCB, most common place is where the power terminals go through the board, as the cables flex a tiny crack appears round the terminal, what make is it?

[jonbarrett]

The amp is quite large and velcro'd to the topside of the cowling that goes over the passengers knees. Doesn't fit that well.

The amp has it's own power supply and a remote 'on' wire. The outputs feed the front speakers only. I assume it was part of the digital radio/multi-CD changer set up that was in the car when I bought it.

Not sure what make but is said made in the USA. It has a black ribbed case and clear plastic base showing the printed circuit assembly.

Guess I'll have to take it out and look for dry joints.