I have the same problem blue power light blinks 3 times

These blinks [flashes] are fault indication (Error Codes). From the number of blinks occur at one time switch ON, you can get an idea about the faulty circuit section inside it. This will make repair easy. These are called blinking codes. Make sure about the exact number of blinking of the standby/power LED, by switching On & OFF the set, for at least two times. Count it carefully. If you wish to get some details, check the site linked here. It has details about blinking codes, and fault locating procedure, to many popular brand TVs and other devices. http://electronicshelponline.blogspot.com/
Blinking codes details to many popular brand TVs are given. Surf the site with patience.

My Hitachi 50" plasma has exactly same problem. I have called local TV service centre, and I was told min. charge is $500 plus $110 for pickup. It is out of the warranty now (almost 3 years old), I really don't know what to do.

very common issue for these sets! p50h401 and p50s601 are almost the same.

for more info on this set please check out http://www.hometheatershack.com/forums/hitachi/38229-hitachi-p50h401-led-flashes-3-times.html
if will tell you how to trouble shoot this tv. these tv's are known for two caps in the power supply to go bad and they need replaced then you have to test the sdr buffer boards if they are bad you need replacement boards or you can send them off to be repaired.( Repairing the buffer boards is a lot less then replacing them ) the link for the repair guy is on the page. this guy also sells the repair on ebay but if you contact him directly i beleave the price is lower. just tell him you were send over by home theater shack.

my hatachi hd/1080 tv has a solid blue light on and it wont turn on i push the reset button on the bottom right and it still wont turn on

turn tv on and screen does not come on power blue light blinks three times.

Ur power supply it dead.must replaced.

Does anyone know how to fix this very common Hitachi problem without paying a repair man? And if you did pay a repair man did they fix the problem, and how much was it? I absolutely LOVED this TV before this happened. :(

I am having the same problem, what was the solution to this problem? And how much did it cost to fix it?

Press the reset button...it's on the bottom to the right (underneath the TV). Same thing happened to me.