Question about Yamaha P4500 Power Amplifier 2-Channel

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Yamaha P4500 service manual

Anyone know where I can source a service manual for this amp? I have tried most of the manual sites and they offer user manuals but not service manuals.

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Re: Yamaha P4500 service manual

One thing for sure Yamaha will not turn their back on their customers for support. What they normally say is that you contact your nearest service center for assistance. But you know you have a very good chance of getting a copy of the service manual since this is a very old model. i have the same amp being used in our church and yamaha service Japan has sent me by postal mail. technology nowadays is much different so maybe they can even send you in pdf format.

Write them by postal mail :
Yamaha Corporation
A/V PA Service Department
10-1, Nakazawa-cho, Hamamatsu, 430-8650 Japan.

simply tell them you need the manual and you are doing the servicing on your own. No one in your area can help you with it.

anyway, what is wrong with your P4500, it's a good amp but sensitive. very good design, hard to troubleshoot if you're not familiar with Yamaha amps. The main parts you can not replace buying from a local store though you may get the same part numbers specially power/driver transistors. it always comes in complementary pair critically matched by tthe factory. i tell you don't get the replacement anywere but Yamaha only. Yamaha have made to order power transistors tailor made for this Amp. you'll find the same transistor number outside but when you plug the unit, it wont last and worst it bursts !!! be carefull. Very hard to scan a copy of manual for you, but if you dont get a reply from Japan you can email me and we'll try to find a way to send you a soft copy.

Reden (
Yamaha service from Saudi Arabia 1996-2001

Posted on Mar 19, 2008

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Re: Yamaha P4500 service manual

I managed to get a free PD2500 schematic online . the amp I was fixing turned out to need some solder reflow on the PCB ( on the channel with the problem)
Works like a charm.

If that model has the tubular cooling fan I suggest taking it out and cleaning/lubing it.

Posted on Feb 08, 2008

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Re: Yamaha P4500 service manual


let me tell you something. don't vote me unless you think my point of views bingo's and give me "fixya" rating.

i m pretty sure that manufacturers do no provide service hand manuls to anyone except to their "authorized" agents/dealers. In very odd cases they sell manuals as part of accessories. Unless you are an insider or unless some how some older models may have copies slipped out. my answer is "no chance".


Posted on Jan 28, 2008

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The manual says the heat sink is too hot or an unacceptable DC voltage was sensed going out.

Generally speaking, an amp attempts to protect itself from heat, shorts, overloads and operator exuberance by refusing to turn on or stay on; or it may turn on but produce no audio to the speakers.

Overloads can be from excessive periods of high output or marginally low impedance loading by the speakers; and shorts would be wiring issues or a speaker blowing up.

You should be able to feel if it's hot. WHY is it overheating? Make sure it has sufficient ventilation on all sides and that vent holes are not blocked by dust balls. Ensure the fan (if equipped) is running as designed (some only operate on demand). Clean dust and debris from it.

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This is a service manual of your device and it can be downloaded for free and I hope it is suitable for you (included schematic diagram). Go to this web site:

When you use the link you get to a page where you have to wait some minutes to be possible the downloading so please be patient.
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