Sony KDF-E50A12U TV Swith on ok, after about 30 seconds the tv goes into standby mode, green power light on with 3 rapid red flashing lights. Any assistance appreciated

Sounds like power supply trouble

Hello
Three blinks of standby light to Sony TVs indicates that the regulated voltage output from power regulator board is above thatn normal. The problem is with its power supply regulator board. Replace all the electrolytic cpacitors on that board with new ones. Replace all of them including small and large ones, at one time. OK.

Your fan or balast is bad. Try replacing the fan first. Sounds like a thermal sensor is tripping. Hope this helps.

How many times red light is flashing after 3 seconds long pause?
This info will help me to sort out problem.
Thanks.

Power supply failure

How may flashes the LED does? This error code will tell you what is the problem.

Hi,
If its Sony KDF-E50A12U TV then its problem of weak lamp in TV that will be replaced and problem will be fixed. Lamp light on TV front will lit in case lamp is dead or broken but current symptom shows Lamp is not either dead or broken yet it got weak in result and causing problem.
Lamp replacement is easy and would be written in user manual.
Please but Sony original lamp for TV safety.
Let me know if you have additional question.
Thanks.

Two blinks - B+ over current protection (OCP), unit goes to the standby mode then displays the 2 blink fault. Could be a short in the power supply of any of the circuits.

5 times Red LED blinks means Lamp Driver Error. (KDF-55WF655)
2 possible reasons, either Lamp is gone or Ballast Supply got bad.
Replace lamp first, in most cases it solved the problem.
How old is this TV and did you replaced lamp recently?
Thanks.

tv works for about 2 minutes, then shuts itself off. the red standby light flashes 50 times, then the tv. comes back on for approximetly 2 minutes then goes off again, only to repeat again