Tell you what - here is the exact copy from the service manual - highlighting the issues I brought up before.
There's really not a need to go into the error history.
There are only 3 conditions that will cause the simultaneous blinks as I have stated before.
1 - bad lamp. even if it plays for a few minutes - it may be weak. These lamps are charged with mercury vapor - and when the high voltage from the ballast fires it - it may not have enough to sustain the picture for long.
2 - bad ballast - there is a charge capacitor that, if weak, will not sustain the high voltage for the lamp to stay lit - or there may be a cold solder joint that will expand and not make contact after it heats.
3 - lamp door cover not being recognized as closed. This could be a bad switch...or warpage of the door.
See the chart below.
Step 1 is to verify proper operation (or bypass the) door switch.
Then, if the same replace the lamp (no way to test without a high voltage power supply.
Then finally, the ballast is replaced (no way to test without a high voltage multimeter.
I always suggest changing the ballast if it has been 5 years of service - or the 2nd lamp - as they do weaken over time.
As always - if you have additional - Just Ask.