My plasma tv PDP-503PU when first turned on works fine for twenty minutes then it goes out and the red light flashes continuesly.I bought a can of compressed air dusted everything out and because it l

SOURCE: Pioneer PDP-503PU

Very possible,but yet,this might be the manufacturer defect power supply which they will fix it for you free;but before we jump to this conclusion,you need to test it first:
-Unplug the power cords.
-Unplug the media video cable from the box to the tv.
-Check all the pins on the video cable are in place as well as the connectors both behind the TV and the media box.
-Reconnect the media box and TV with the video cable(DVI+VGA in one) and have at least a video component hook up to it(ex. dvd player/VCR or comcast box) be sure this video player is turn on and running,at the same time,be sure it is under the right video input.
If you have tried the above steps but still doesn't work,call 1-800-pioneer Tuesday-Thursday at7amPST and address your issue to them.
Let me know if you have any additional questions!
solutiondoct

SOURCE: plasma TV mod PDP-5016HD not turning on

The most likely the TV has a power supply related problem. The most common thing to go out is the circuit board that supply power to the screen. Commonly called a Backlight Inverter Board.
I can't say it's 100% the problem because I can't actually look at the tv over the internet.
If by chance the TV is still under warranty, go that route.
If not under warranty and If you have some electronic experience, you can purchase a Service Manual over the internet and diagnose the source of the problem and fix it by soldering in the new part. The Service Manual will give you circuit diagrams, test points, and part# lists. Usually, cost under $20.

I hope I shed some light on the subject for you.

electronic & computer repair& servicre

• 12061 Answers
• Posted on Mar 12, 2011

SOURCE: I have a Pioneer PDP-R05G

This is a classic "Hic-upping" switchmode power supply problem. The protection circuitry inside the SMPSU, has sensed a severe potential problem, and is attempting the shutting of the set, down to avoid a fire, explosion, or both.
This set had developed a problem, that is so severe that the set must be shut down, (This set should be removed from the Power),
What is happening is the internal "Fault" that is causing the Protection Circuitry , to detect the problem and attempt to shut down the set, keeps restarting the set, because as soon as it shuts down, the "Faulty" component(s) cool down?, and the "Fault" ostensibly "Clears" so the PSU starts up again, only for the component(s) to heat up, whatever, again and fail, so it shuts down, and if left unattended, this would continue on until the part eventually failed. As related this is called a "Hic-upping Power Supply". Any fault that involves the power supply is usually quite serious, and needs a professional, usually, unless one is familiar with servicing current day, televisions.
And in my professional recommendation, you should get a "Quote" for repair, from, an, Approved Service Center. Now, this point is very important for a good result, Always contact, their "Local" or a, "Head Office" Philips in your case. Ask them, for a referral to an authorised servicing center, where you ask for a "Quote". Now, when you get the information you want, then you can decide as to repair of replacement.
The reason we want an approved agent, is that way, all the engineers are trained on their own brand sets, they have seen almost all faults, and will get the job done quicker, and for less cost, and usually have parts on hand, also sometimes, there has been a service bulletin in issued and the repair may be subsided or even free. There are many, many, many reasons that display this symptom, one must work through the troubleshooting steps to isolate and identify, the Cause and repair that and any damage done.
http://www.pioneer.owner-manuals.com/PDP4360HD-service-manual-PIONEER.html
service manual link above,
as an aside here, sometimes things in storage can quickly degrade especially big low value capacitors, these increase in internal resistance, and all sorts of problems ensue, this is why, say, military things are cycled at least weekly when in "Moth balls" to prevent exactly this.