Pioneer A-P510 Amplifier

[philpeel]

Hi

Having a few problem with the above amp. Works fine at low volumes when turned up the protection relay keeps clicking on and off. The louder or 'bassier' the sound the more it clicks.

Had it in bits and noticed that the small cpu fan that cools the heatsink has stopped working - so suspect this may have caused something to have overheated. The heatsink is attached to two transisters.. and a large unit with Pioneer Amplifier printed on it.

I'm not too clued up about how to start testing what the fault is.. would apprectiate any pointers...

thanks

[Justmanuals]

Take it to a shop to get repaired before you get electrocuted!

[email protected]
_________________
Want To Fix Something?
http://www.manuals4you.com

Need a manual now? Instant Download
http://www.justmanuals.com

[Guest]

I was after a more helpful answer than that..

[Justmanuals]

'I'm not too clued up about how to start testing what the fault is.. would apprectiate any pointers... '

My advice is the best advice anyone could give you. It just may save your life.

[email protected]
_________________
Want To Fix Something?
http://www.manuals4you.com

Need a manual now? Instant Download
http://www.justmanuals.com

[vtech]

Without circuit schematic or familiarity, it is not easy for the average person. I know that some cooling fan circuits were designed to only operate when a specific temperature was reached. Not sure if it's the case here or not? this type of problem could be anything from a defective relay, protection or power supply problem.
Just because relay happens to rhym with music density, does not tell you a whole lot. The key is to monitor the protection circuitry with measurements to determine if it's a valid protection event or simply buckling under load due to supply instabilities. Dried up electrolytic caps can certainly play a role. With audio in general, you need a lot more diagnostics unless you are familiar with the specific unit.

[Guest]

Justmanuals

Just becuase i'm not clued up about the specific doesn't mean i'm going to jam my fingers into anything that i'm not sure about. My multimeters has long test probes Thanks for the conern.. but I suspect that if you had a service manual on your site for this you would have have given me the same response that you have in 90% of your other posts and would have been happy to sell me one.

vtech.. thanks for the assistance.. nothing on the board looks burnt out and i've tried applying voltage to the fan and it doesn't spin so the fan is certainly defective. the heat sink get very hot very quickly so i suspect the fault is either the transisters or the pioneer amplifier unit that are clamed to the heat sink

[vtech]

If the fan is definitely bad, why not just replace it with a similar rating & see if it has any effect?

[Guest]

i think continued use without the fan may have caused the probem - but the fault is there before the heatsink has warmed so dont think replacing this alone will solve the problem.
i was thinking of bridging the relay as a temp measure to see if the problem goes away - and measure the voltage at the speaker terminals. if it does it suggests to me the power supply is ok..maybe.
i'm going to measure the voltage supply to the relay and see how much this fluctuates while the problem occurs.
note that everything works ok through headphones.
i think the fault is likely to be the amp module is faulty in which case it's probably not worth repairing.

[vtech]

More likely, excess heat has caused cap(s) to dry out which again w/out further diagnostics may in fact not be worthed.

[Guest]

ok.. thanks v much.

is there a way to test the caps without a capacitance meter?

and can i do this without removing them from the board?

Phil