AWA MHDV2211 (Board 303C3206072) - voltage regulator failure
Today, I received an AWA MHDV2211 TV to repair.
Despite replacing all but the 400V CapXon unit in the non-PFC power supply and C163 (after a switching regulator) on the main logic board (303C6206072), I still get the effect as per my YouTube video before I replaced them - all but one of the electrolytic capacitors I replaced were Aishi units.
Elsewhere on this forum, I have read about linear voltage regulators failing in flat panel TVs
; so I decided to measure the output on each of them (with the set powered on and not in standby) and found that U14, an AMS1117-ADJ was faulty, of which I did not have any spares on hand; so I used a more readily available LM317T which was similar to the original and this fixed this problem.
Apparently, U14 is the regulator for the CPU core and/or RAM; output loss from this regulator (after warming up) caused the CPU to crash.
My YouTube video of this fault: http://youtu.be/X0yzeK-aNQY
Despite replacing all but the 400V CapXon unit in the non-PFC power supply and C163 (after a switching regulator) on the main logic board (303C6206072), I still get the effect as per my YouTube video before I replaced them - all but one of the electrolytic capacitors I replaced were Aishi units.
Elsewhere on this forum, I have read about linear voltage regulators failing in flat panel TVs
; so I decided to measure the output on each of them (with the set powered on and not in standby) and found that U14, an AMS1117-ADJ was faulty, of which I did not have any spares on hand; so I used a more readily available LM317T which was similar to the original and this fixed this problem.Apparently, U14 is the regulator for the CPU core and/or RAM; output loss from this regulator (after warming up) caused the CPU to crash.
My YouTube video of this fault: http://youtu.be/X0yzeK-aNQY