Power supply output for Yamaha p4500 secondary output for the power supply so that i could check the voltage

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

http://www.retrevo.com/support/Yamaha-P4500-Amps-manual/id/962bh144/t/2/

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.

If the amp comes back on after cooling, you're lucky. They only have so many self-protection cycles in their lives so continuously resetting or cycling their power without addressing the cause can do more harm than good.

If it protects immediately on a cool power up you should disconnect the speaker connections and try it 'nekkid'. If it comes up then diagnose which lead(s) are shorted. If it does not come up the problem is internal and should be left to an experienced and competent hands-on tech.

Check for loose speaker connections at the speaker as another possible root cause for intermittent shutdown.

'Splitting' leads is never the best way to distribute a signal. The best solution is to use the parallel inputs of the Yamahas to chain them together: mixer to amp1, amp1 to amp2, amp 2 to the Cloud. You should only need to use one input on the Cloud to drive all the channels, using the input switches at the rear.

Let me know if you need any clarification on this.

Check the voltage input to horizontal output transformer [LOT]. Check the voltage at the collector point of the line drive transistor. If the line drive transformer primary gets open this type of fault mau occur. Also check the frequency ant the collector point of line drive transistor and the base point of line output transistor. It should be aroung 15625 Hz.
Check and replace the horizontal output transistor if needy. Replacing it is better. The horizontal output is not working or a short in secondary power supply of SMPS or lot secondary, is your problem

there is a possibility of a shorted turn of the flyback transformer. To test. short B-E together on the horizontal output transistor and connect 60W globe across C-E. measure voltage across lamp - if it comes up to 135v then you have a short either in the horizontal circuit or secondary circuit off the flyback transformer or even the transformer itself.

TURN THE BALANCE CONTROL IN THE MIDLE

you need to check the voltage output of your power supply section.This power supply supply is a switching type power supply.there is a chopper transformer in there.its supply is a dc voltage unlike any other transformer which is AC supplied on the primary..First step.
1.Using a multitester measure the primary supply it is a DC voltage around 220v - 110 VDC
2.Measure the secondary output.The out put is AC voltage the supply for the B+ going to plyback is 115vdc the second output is 12v run through a regulator and the regulator lower the voltage to 5vdc.this 5vdc supplies the system IC and the jungle IC.this ic process the switching of the plyback transformer and the plyback transformers output supplies the voltage of the whole system including your relay in the degaussing section....once the plyback is activated the tv will now turn on...

good luck!Hope i helped you..

please rate my help..god bless!

there is a short circuit protection and overoad protection to smps so o/p capacitor may short or secondary diode may short .so check voltage at primary when switched off after 33seconds whether switching process is going or not for that check dc volt at i/p capacitor then check volt at collector of transistor if metr shows 1digit then switching is going if not then meter shows full dc volt check component near about that

I would stick to replacing the whole power supply rather than bits and pieces.

http://store.richspsxparts.com/pl2posubov4.html

The website above sells PS2 power supplies.

If you want to try and replace bits and pieces, you can probably find individual components at Radio Shack... but you would have to be good at troubleshooting and soldering.

first check your input cable-disconnect it and check if the problem finished---you will have a problem in input(cable or device)-start with another cable then your input device.
if the problem still check your out put cables(speakers cables)for short circuit or touch the bare wire with amplifier body.-try to clean volume controls with spray contact cleaner---confirm good connection in amplifier rear and in speakers rear.

im from Yamaha service before and i know this model can handle as low as 2ohms per channel. I have to check on my manuals though if bridged. i dont see any reason why it cant. and it has a bridge option input stage... let me get back to you again in the days to come.

or email me [email protected]

i have a service manual to check on this. got to dig on my closets..