Hi everyone,
I am working on this set I picked up off Craigslist.
When I turn it on I get the normal Samsung chime but the backlights never come on. I can take a flashlight to the panel and see snow being displayed on a channel with no signal. If I hook up my cable line I get sound as well.
A couple things I have tried already:
Unplugged the mainboard from the power supply to see if the backlights would come on. No difference.
I read on the forums that the JP852 jumper may cause the backlight to flicker and that it should be cut, which I did with no change.
Voltage readings from plug JP824 from mainboard to power supply:
1- B13 12.31vdc
2- Lampdet 0.00vdc
3- B13 12.31vdc
4- Sw Inv 5.14vdc
5- B13 12.31vdc
6- Pwm_Dim 1.66vdc
7- Gnd
8- H_Sync 1.67vdc
9- Gnd
10- Gnd
11- B5v 5.15vdc
12- Gnd
13- B5v 5.15vdc
14- B5v 5.15vdc
15- 18vs 12.31vdc
16- A5v 5.16vdc
17- 13/18vs 12.31vdc
18- Pow_on/off .88vdc
Voltage readings from plug CN1802 from power supply to inverter
1- 12v 12.23vdc
2- FB 0.00vdc
3- FB 0.00vdc
4- Gnd
5- Gnd
6- LD 8.94vdc
7- LD 8.94vdc
I have checked the fuses on the power supply and both are good.
Voltage across the large 450v caps is 390vdc on each
Anyone have any ideas what to check next?
Thanks in advance!
I am working on this set I picked up off Craigslist.
When I turn it on I get the normal Samsung chime but the backlights never come on. I can take a flashlight to the panel and see snow being displayed on a channel with no signal. If I hook up my cable line I get sound as well.
A couple things I have tried already:
Unplugged the mainboard from the power supply to see if the backlights would come on. No difference.
I read on the forums that the JP852 jumper may cause the backlight to flicker and that it should be cut, which I did with no change.
Voltage readings from plug JP824 from mainboard to power supply:
1- B13 12.31vdc
2- Lampdet 0.00vdc
3- B13 12.31vdc
4- Sw Inv 5.14vdc
5- B13 12.31vdc
6- Pwm_Dim 1.66vdc
7- Gnd
8- H_Sync 1.67vdc
9- Gnd
10- Gnd
11- B5v 5.15vdc
12- Gnd
13- B5v 5.15vdc
14- B5v 5.15vdc
15- 18vs 12.31vdc
16- A5v 5.16vdc
17- 13/18vs 12.31vdc
18- Pow_on/off .88vdc
Voltage readings from plug CN1802 from power supply to inverter
1- 12v 12.23vdc
2- FB 0.00vdc
3- FB 0.00vdc
4- Gnd
5- Gnd
6- LD 8.94vdc
7- LD 8.94vdc
I have checked the fuses on the power supply and both are good.
Voltage across the large 450v caps is 390vdc on each
Anyone have any ideas what to check next?
Thanks in advance!
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