Hello every one ....Samsung PN50B550T2fxza was working great and one morning it shut it self down and power back up .Suspected power surge .Then thru the day it went completely dead, though it is the caps but they all appeared good. The only way i was able to bring it back to power back up is to disconnect the Main board ( BN96-12139A). I bought the manual and followed trouble shooting process i had standby light up front and TV was very responsive with picture and sound except it power it self down after 15-20 Minute minute to exact with all Voltage reading correctly at VA, Vscan & Vg ..fast forward .
I did not want to dump money on a main board without extra support as i though man it could be power supply so my local electronic store trouble shot it and said main board .. However now when i brought it back home the screen was totally dead and no standby light , NO SMPS relay clicking NOTHING , No Logic B’d LED on, all AC Input voltage present , connector going to power supply show 122 AC ,no blown fuses . Pin #3 STBY =5v Yes , Pin #2 PS-On =0 V So since it is yes repair manual show replace main
i took it back to the shop as the symptoms got from bad to worse after i picked it up
( specially i had picture , sound , standby light up in the panel ) they said it's main board . Then off course they told me the TV will be dead without a good main . Well it wasn't when i took it in and it was operational except it power it self off and goes dead and now it's nothing but weight. Well that did not go any where with them , So i took it home and I retested by starting at the SMPS (Power supply ) same result as my 1st test , SO i picked up a refurbish main board from e-bay seller stuck it in but got the same result = dead set with the same test result on the voltmeter.
Whats the odd of me buying a bad Main board . Also what else they could off done( the electronic Shop) that resulted from having a TV that with some what functioning to nothing but paper weight ..
I am buying another main but
Does the revision # have to be the same when buying a refurbished main
If the main board is truly bad would the set behave in this manner .
What happened to my Logic B’d LED on , It use to function but now all is gone together
i am open to all suggestions.
Thank you
I did not want to dump money on a main board without extra support as i though man it could be power supply so my local electronic store trouble shot it and said main board .. However now when i brought it back home the screen was totally dead and no standby light , NO SMPS relay clicking NOTHING , No Logic B’d LED on, all AC Input voltage present , connector going to power supply show 122 AC ,no blown fuses . Pin #3 STBY =5v Yes , Pin #2 PS-On =0 V So since it is yes repair manual show replace main
i took it back to the shop as the symptoms got from bad to worse after i picked it up

Whats the odd of me buying a bad Main board . Also what else they could off done( the electronic Shop) that resulted from having a TV that with some what functioning to nothing but paper weight ..
I am buying another main but
Does the revision # have to be the same when buying a refurbished main
If the main board is truly bad would the set behave in this manner .
What happened to my Logic B’d LED on , It use to function but now all is gone together
i am open to all suggestions.
Thank you
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