Samsung tv blinking panel light

[chiefdan]

Samsung TV LNT3242H Power board BN44-00192A (MK32P3)

Problem: No picture, no back light, no sound, just front blinking red light

I have been looking at this tv for about a week now as a novice, and can't find anything wrong. I have tested all caps visually and with ESR and cap meter. Can't find any bad ones. I have tested all diodes some in circuit, some out if they tested positive both ways, but found no bad ones. I replaced the large resistor RM801 with a 2w but the original was not bad. It had that glue crap all over it and the caps next to it, but had no carbon lines. Other places on the board had the burnt glue, but no carbon lines anywhere.

I had thought the Mosfet CP801S might be bad because I could never get a good reading on it, so I just put it back in.

I took the ribbon cable between PS mainboard and jumped I did have 5 volts on the SB. After jumping I had the following voltages;

Mainboard cable

12.3v @ 12v pin 7
5.3V @ 5.3 pin 13
5.3v @ 5.3 pin 15
12.1v @ 13V pin 19*******
12.1v @ 13v pin 21*******
12.0v @ 12V pin 4
5.3v @ 5.3v pin 14
5.3v @ 5.3v pin 16
12.1v @ 12v pin 22

small ribbon coming from main board

det 5.14v
pwm 4.25v
adm 002v
blu .009v

cable going to inverter

pwm 4.25v
adm .002v
bl .011
nc .311
all 24's had 24v

leg of RM801 323.4V
leg of DB851 5.22v
leg of bridge (with negative meter lead clamped to ground screw)
DC- 57.9v
DC+ 59v
With meter negative to negative leg of bridge 117dcv

I also took the t-con out to look for blown fuse, but could not find on on the board. I also jumped the back light board and it came on.

So that's kinda where i'm at. Any of your expert tuteledge would be greatly appreciated. pictures attached.

[budm]

Re: Samsung tv blinking panel light

"leg of RM801 323.4V
leg of DB851 5.22v
leg of bridge (with negative meter lead clamped to ground screw)leg of bridge (with negative meter lead clamped to ground screw)
DC- 57.9v
DC+ 59v
With meter negative to negative leg of bridge 117dcv"
When you check the DCV on the primary side, you cannot use the chassis/safety GND as the GND ref for the meter, you have to use Negative leg of the main filter cap as the GND ref point.
You should have about 160VDC between the two legs of the main filter cap, it should jump up to >360VDC when main board sends the PS-ON to turn on the PFC Voltage booster circuit and the rest of the power supply.

"bl .011" Right now the main board is not sending the BL-ON signal to turn on the backlights.

[chiefdan]

Re: Samsung tv blinking panel light

Thank you for you reply budm. Voltage across the large capacitor is 158v when ps is not jumpered. With the ps jumpered, the voltage goes to 383v. Is it your opinion the main board is bad?

[Shinju]

Re: Samsung tv blinking panel light

Just an fyi, Samsung panels do not use a LED error code system. a blinking LED on the front of the panel is normal for all Samsung units and means nothing.

[Hamie]

Re: Samsung tv blinking panel light

Yes mainboard isn't sending ps-on or bl-on signals.

[chiefdan]

Re: Samsung tv LNT3242H blinking panel light

Thank you Hamie and Shinju for you reply. I really appreciate it.