Samsung LN46D630M3F ver. SQ01

[kartwood]

Hello Group!

works fine for 30-60 min, then backlight flickers briefly then goes until things have cooled down somewhat.

PFC boost voltage is about +392v when it works and drops to about +160v. Set remains on except for B/L.

This set does not use the power supply with the superfluous jumper.

thanks for any suggestions.

[CapLeaker]

Re: Samsung LN46D630M3F ver. SQ01

Look at the PSon and the BLon signal on the PSU when that happens.
The BLon signal comes from your main board. You could take the BLon wire out of the connector or cut the cable and jump a 1k resistor between STBY and BLon on the PSU and turn on the TV.

[kartwood]

Re: Samsung LN46D630M3F ver. SQ01

Thank you, Mr. leaker! When I disconnect CN802 going to the main, BLU_ON (CN803-3) floats high, turning on the back lights.
When the fault is present, B/L is not there under any conditions.

Silly thing has been working fine for the past few hours

[CapLeaker]

Re: Samsung LN46D630M3F ver. SQ01

Ok then... exercise all connectors, make sure all the screws holding the boards to the chassis are tight and cross your fingers.

[Glitcher]

Re: Samsung LN46D630M3F ver. SQ01

Just got this same set the other day with the same problem, backlights going off. Checked all the voltages and signals going to main and inverter and they all remained the same even when the backlights went off. Concluded it was either a bad lamp or the inverter. Just swapped out the inverter and the TV now remains lit and seems the problem is fixed. Just for reference.