Samsung ue324h5000w no backlight

[LE GRAND]

SAMSUNG UE324H5000W NO BACKLIGHT
SAMSUNG UE324H5000WWZF VER N° :02
MAIN BN41-01795A
PSU BN44-00493B
pwm IC 2S110
INVERTER PFFF may be SLK2012M


SCREEN LTJ320HN07-V
T-CON BN41-01797A

CNM803 VOLTAGES
B5 ---------- 5 .2V
B13---------13V
PS_ON ----3.5V
A5V---------5V
P_DIM------0.2V
BLU_ON ---0V
CNKL802 VOLTAGES
TOP1+ --------0V
TOP1- ---------0V

MA IN CAPACITOR CM 801 802 292V
CM806 15V
If i deconnect the main from psu no back light
If i deconnect leds connector cnlM02 no voltages in
So any ideas

[dick_barton]

Re: Samsung ue324h5000w no backlight

You have the power on signal PS_ON but not the backlight on BLU_ON signal.


Disconnect the mainboard and connect a 1K resistor between 5V and BLU_ON and another 1K from 5V to PS_ON and the backlights should come on.

Edit
+1 I agree with dskall that the main capacitor voltage does appear to be too low.

[dskall]

Re: Samsung ue324h5000w no backlight

Main cap voltage looks about 100v low

[LE GRAND]

Re: Samsung ue324h5000w no backlight

i think main cap is norm because there is no PFC
PS ON LOOK IN NORM THERE IS IMAGE BUT NO BACKLIGHT

[dick_barton]

Re: Samsung ue324h5000w no backlight

Do you have a schematic?

What DC voltage do you have between pins 1 and 8 of the 2S110

[LE GRAND]

Re: Samsung ue324h5000w no backlight

No i havent a schematic for this psu and google too

[budm]

Re: Samsung ue324h5000w no backlight

How does OP measure the Voltage on the main cap, between the two legs or using chassis as the GND ref. for the meter?

[dick_barton]

Re: Samsung ue324h5000w no backlight

Fair point, should have asked that.

[LE GRAND]

Re: Samsung ue324h5000w no backlight

with unit t multimeter ut-61b
vcc 1-->8 ---------------15 V
1---7-----------------
1---6-----------------
1---5-----------------
1---4----------------285V
1---2----------------1.2 V

[budm]

Re: Samsung ue324h5000w no backlight

with unit t multimeter ut-61b
vcc 1-->8 ---------------15 V
1---7-----------------
1---6-----------------
1---5-----------------
1---4----------------285V
1---2----------------1.2 V

What is you incoming AC line Voltage?

[budm]

Re: Samsung ue324h5000w no backlight

BTW, since the main board is getting correct Voltage then the BL-ON should be present.

[LE GRAND]

Re: Samsung ue324h5000w no backlight

now 213v 50 hz so 220V line

[budm]

Re: Samsung ue324h5000w no backlight

213V x 1.414 = so the DCV between the two legs of the cap should be around 300VDC.
If you disconnect the cable from power supply board to the main board, what DCV do you have on those pins of CNM803?

[LE GRAND]

Re: Samsung ue324h5000w no backlight

B5 ---------- 5 .2V
B13---------13V
PS_ON ----3.5V
A5V---------5V
P_DIM------0.2V
BLU_ON ---0V
CNKL802 VOLTAGES
TOP1+ --------0V
TOP1- ---------1,4V
main cap 284 volts
so no changes in voltages only top1- with main connectd or disconnected is above 1v ~1.4 V

[dick_barton]

Re: Samsung ue324h5000w no backlight

with unit t multimeter ut-61b
vcc 1-->8 ---------------15 V
1---7-----------------
1---6-----------------
1---5-----------------
1---4----------------285V
1---2----------------1.2 V

The 15V for VCC looks OK.

[budm]

Re: Samsung ue324h5000w no backlight

B5 ---------- 5 .2V
B13---------13V
PS_ON ----3.5V
A5V---------5V
P_DIM------0.2V
BLU_ON ---0V
CNKL802 VOLTAGES
TOP1+ --------0V
TOP1- ---------1,4V
main cap 284 volts
so no changes in voltages only top1- with main connectd or disconnected is above 1v ~1.4 V

O, I just want to verify if the BL-ON pin has pull-up resistor for self test or not
So you need to use 500~1K resistor between A5V and the BL-ON pin then run the board by itself to see if the backlights will come on, you may need another resistor between P-Dim and A5V if the backlights do not come on.
Pictures provided by shopjimmy.

[MICROTECHSERVICE]

Re: Samsung ue324h5000w no backlight

hi everyone on this model whichi have done over 30 sonce 8 months please check you leds you will find odd 1 short circuit,and led protection coming into force, hope it helps

[budm]

Re: Samsung ue324h5000w no backlight

hi everyone on this model whichi have done over 30 sonce 8 months please check you leds you will find odd 1 short circuit,and led protection coming into force, hope it helps

Shorted LED or the wiring/LED board/connection shorted?

[LE GRAND]

Re: Samsung ue324h5000w no backlight

With resistors in blu-àn and/or pdim there is no backlight

[LE GRAND]

Re: Samsung ue324h5000w no backlight

the 4 led strips are verified and ok