help with pioneer DEH-P770MP
#1
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help with pioneer DEH-P770MP
my pionneer head unit went out a long time ago, and i never figured out why, i simply replaced it with an old one, but i looked at it the other day and saw that the fuse was blown so i replaced it and it keeps blowing everytime. i brought it back into the house and i have a dc power supply for my room, so i hooked it up to that, when it has a bad connection it makes a weird noise, and so it did. i think it has a short in it somewhere but i dont know where to begin, i would love to get this thing working again cause i hav another car that doesnt have a HU. any suggestions?
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i think it has something to do with the outputs... because before it blew out, it always had the whine from the alternator... so a shop i brought it to said it was because of the lack of ground going to the outputs and they said they grounded it for me... bout 2-3 months later i was driving hitting hard, and it blew out completely so iono...
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Try a bigger fuse. If it still blows somthing moving like the cd reader ribbon is exposed to the metal chassies of the radio interior so when ever the car shakes it or it moves to a certian track, Puff.. I had the same model and that was my problem.
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well it says a 10A on the head unit itself... iono im just gunna take it to a repair shop and see what they say, if i can fix it then i will if i cant im just gunna pay for it if its cheap
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Grounding outputs
Grounding the outputs is probably what caused it to blow. The outputs on that unit are balanced transformerless, which is basically two output stages run out of phase, with each amp driving each leg of the speaker. If either of the speaker wires was grounded you shorted that amplifier's output to ground.
Alternator whine can be caused by a couple of things. If your alternator has a bad diode (rectifier) it will cause a whine. Or a ground loop could cause a whine. The bad alternator diode could have contributed to the failure of the radio but a ground loop most likely didn't
If your HU is blowing fuses check the power amp ICs first. A simple check would be to measure the resistance across the speaker outputs. If you get a reading any lower than a few hundred ohms the chip for that channel is most likely blown.
Hope this helps...
Alternator whine can be caused by a couple of things. If your alternator has a bad diode (rectifier) it will cause a whine. Or a ground loop could cause a whine. The bad alternator diode could have contributed to the failure of the radio but a ground loop most likely didn't
If your HU is blowing fuses check the power amp ICs first. A simple check would be to measure the resistance across the speaker outputs. If you get a reading any lower than a few hundred ohms the chip for that channel is most likely blown.
Hope this helps...
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#8
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well, the alt is good cause my other pionner head unit works just fine with the same wiring... the whin only happened after i got this premier... so if i did short the aplifiers output to ground... how could this be fixed? is it better to just let a professional do it?