samsung ps42b451b2w

[samisat]

Hi flaks I got in this tv which no pic but got sound. as normal I checked ysus and driver for faulty fet or caps but nothings found so I put bake the Ysus and driver on tv and back light fired up. tv worked for 3 days and then one morning same issue,I did unplug same board and put them back then again fried up everything ok but after 2day went same issue. any idea?
Thanks for ur help

[downunder]

Hi Sam,

Nothing leaps out at me, but you'll have to do some checks when it's in a failed state. Check Vs and Va. Is the LED on the logic board flashing? Does the inbuilt pattern generator produce test patterns, etc?

Not aware of any stock standard faults on these except for CS809 (68nF 1250V) and CS810 (39nF 1250V) in the power supply, which can bulge and drop out Vs and Va.

I've uploaded the training manual for this model to the forum, but probably wont be of much help. Might be helpful to turn on your spell-checker.                Bruce

[samisat]

Hi thanks for ur advice , vs and va always exist even when failed to fire up. Also led blinking on logic board .
Thanks

[downunder]

Well, they're good signs.

May I suggest you disconnect the upper buffer board from the Y-Main, turn the TV on, and see if you get a picture in the bottom 1/2 of the screen. If not, refit the board and repeat the same with the lower buffer.

If this comes to naught, try the pattern generator. Are you familiar with the procedure for this?     Bruce

[samisat]

Dear Bruce I did some dry joint on power supply and since that time working fine.Thanks for your help.
Regards sami 

[downunder]

Good show, Sam. Nice feedback, too.

Bruce