Samsung LN37A550P3F(XZA) backlight issue

[taman]

Just this morning, the TV went blank - no backlight. If I turn off and on the TV, the backlight is good for about 5 minutes then out again. I haven't taken it apart yet, but I'm guessing a capacitor issue on the Inverter board.

Can anyone point me to a schematic of the inverter board for this model?

[budm]

Re: Samsung LN37A550P3F(XZA) backlight issue

There are more than one version of this TV model.
http://www.shopjimmy.com/catalogsear...ng+LN37A550P3F
Diagram for the inverter board is almost impossible to find.
You need to take the TV apart and upload good clear pictures first.
Bad caps can look normal, you will need to do some Voltages checking first if no sign of caps with bulging tops or burnt parts.

[taman]

Re: Samsung LN37A550P3F(XZA) backlight issue

Board number is BN44-00216A

[budm]

Re: Samsung LN37A550P3F(XZA) backlight issue

Board number is BN44-00216A

That is power supply board, how about the inverter board?
The Black connector going to the main board and the white connector going to the Inverter board have pin name for each one of them, you will need to take the DCV readings for each pin when the TV is working and when it stops working. Make sure to report the pin name and follow by the DCV reading for each pin so we can see what are missing when the TV stops working.

[taman]

Re: Samsung LN37A550P3F(XZA) backlight issue

Inverter board is VIT71037.50 LOGAH REV:1

I'll measure voltages tomorrow evening.

[budm]

Re: Samsung LN37A550P3F(XZA) backlight issue

BTW, for now you should make sure that all the hold down screws for the circuit boards are on tight.

[taman]

Re: Samsung LN37A550P3F(XZA) backlight issue

I have the TV on its face, back removed, cover over backlight power board removed and screws put back in place. The TV has been on for over an hour and does not fail. I have recorded the voltages of all of the connector pins on the power supply board. Waiting for it to fail.

[Donazan]

Re: Samsung LN37A550P3F(XZA) backlight issue

I have a similar problem with Tasman issue but my model is LA32E420E2R , power board BN44-00438E, inverter board INV32TUC. the backlight will come on when I power the tv and goes off after about some minutes while the tv will still be talking. what will I do pls? I need ur help. thanks a lot.

[taman]

Re: Samsung LN37A550P3F(XZA) backlight issue

TV did not fail while out of the entertainment center. It is probably a little warmer there.
While I had it out, I replaced the caps on the power supply and backlight driver boards. It is now back in the entertainment center. I expect that it won't fail anymore. Hard failures are much easier to diagnose.