Samsung 32" power supply BN44-0351B no backlight

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

What is the correct name of your samsung lcd tv?

for example un32eh4003 we need the exact name of the TV!!!

Correct model of LCD is UE32C5100QWXZT

You say in post #1 But in your list above there is only one voltage shown?

There are also 18 pins (not 16) on that connector and the name of the pins 1 to 18 is given alongside the connector in a box with an arrow pointing to the connector. The connect pins are numbered with odd pin numbers on one side and even on the other.

If you could give the voltages along side the pin number and pin name would be more useful.

For example
Pin 1, GND, 0V
Pin 2, PWM, 1.2V

You ask me to measure the voltages on IC ICD801, that has 16 pins, and these are the voltages:

1 - VCC - 0V
2 - ISET - 0.8V
3 - GATE - 0V
4 - GND - 0V
5 - CS - 0V
6 - AUTO - 0V
7 - RT - 0V
8 - SYNC - 0V
9 - CLIM - 0V
10 - REF - 0V
11 - PWMO - 0V
12 - OVP - 0V
13 - PWMI - 5V
14 - COMP - 0V
15 - FBP - 1.02V
16 - FBN - 0V

These are the voltages of the CNM801...i read on a post that i should put a 1k resistor between 16 and 18 to force power on, so i did it:

1 - D12V - 13V
2 - VDRV - 1.8V
3 - D12V - 13V
4 - BLU_ON_OFF - 2.9V
5 - D12V - 13V
6 - PWM_DIM - 5.126V
7 - GND - 0V
8 - NC - 0V
9 - GND - 0V
10 - GND - 0V
11 - D5.3V - 5.24V
12 - GND - 0V
13 - D5.3V - 5.24V
14 - D5.3V - 5.24V
15 - Vamp - 13V
16 - STBY_5.2V - 5.2V
17 - Vamp - 13V
18 - POWER_ON_OFF - 1.16V

http://www.teleservice-depannage.com...-UE32C5100.htm

you have to disconnect the cable between main and power if backlight appears
main defekt if not power defect samsung uses pull up resistance!!!!

http://www.toms-service-manuals.com/...typekey=0&p=16

see fast track guide take 40 inch

tried to disconnect the cable between motherboard and PSU but backlight doesn't appear...tried also to solder a 1k resistor between pin 16 and 4 to force backlight, without success.
I will look at fast track guide tonight, thanks.

Actually you just need to unplug everything from the PSU, leave the backlights connected, plug in the PSU and the backlights should come on. These Samsungs have a pull up resistor built into the PSU.
However, lets say you have a PSU that doesn't have a pull up resistor built in, you need to put STBY voltage through a 1k resistor to PSon and BLon. If you just put power to PSon alone, it wont fire the backlights.

Tried also to solder a 1k resistor between pin 16 and 4 without success
Thanks

[CapLeaker]

Re: Samsung 32" power supply BN44-0351B no backlight

Hi everyone,
got this TV with no backlight.
Soldered a 1k resistor between pin 16 and 18 of CNM801 and measured all the voltages.
Seems all ok, but in the drive block output i don't have high voltage for the backlight.
In fact the TV power on correctly, can hear the sound and can see that the panel is working if i put a torch in front of it.

How to troubleshoot the backlight? Thanks

Actually you just need to unplug everything from the PSU, leave the backlights connected, plug in the PSU and the backlights should come on. These Samsungs have a pull up resistor built into the PSU.
However, lets say you have a PSU that doesn't have a pull up resistor built in, you need to put STBY voltage through a 1k resistor to PSon and BLon. If you just put power to PSon alone, it wont fire the backlights.

[thoma]

Re: Samsung 32" power supply BN44-0351B no backlight

http://www.teleservice-depannage.com...-UE32C5100.htm

you have to disconnect the cable between main and power if backlight appears
main defekt if not power defect samsung uses pull up resistance!!!!

http://www.toms-service-manuals.com/...typekey=0&p=16

see fast track guide take 40 inch

[dick_barton]

Re: Samsung 32" power supply BN44-0351B no backlight

You say in post #1

Soldered a 1k resistor between pin 16 and 18 of CNM801 and measured all the voltages. Seems all ok, but in the drive block output i don't have high voltage for the backlight. In fact the TV power on correctly, can hear the sound and can see that the panel is working if i put a torch in front of it.

But in your list above there is only one voltage shown?

There are also 18 pins (not 16) on that connector and the name of the pins 1 to 18 is given alongside the connector in a box with an arrow pointing to the connector. The connect pins are numbered with odd pin numbers on one side and even on the other.

If you could give the voltages along side the pin number and pin name would be more useful.

For example
Pin 1, GND, 0V
Pin 2, PWM, 1.2V

[thoma]

Re: Samsung 32" power supply BN44-0351B no backlight

What is the correct name of your samsung lcd tv?

for example un32eh4003 we need the exact name of the TV!!!

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

Here the voltages in DC between the PIN and GND:
1 - 0V
2 - 0.8V
3 - 0V
4 - 0V
5 - 0V
6 - 0V
7 - 0V
8 - 0V
9 - 0V
10 - 0V
11 - 0V
12 - 0V
13 - 5V
14 - 0V
15 - 1.02V
16 - 0V

I already have that schematic, but i don't know which voltages and which signals should i get in the circuits

[R_J]

Re: Samsung 32" power supply BN44-0351B no backlight

This is from elektrotanya.com

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

ok i will repost the photos as attachment:





Actually i got a 1k resistor soldered between pins 16 and 18 of CNM801 to force POWER ON, and i get 2.9V on BLU_ON/OFF signal.

I will measure voltages of ICD801 and i will let you know...thanks!

[dick_barton]

Re: Samsung 32" power supply BN44-0351B no backlight

If you could add your pictures as attachments on the forum it makes it easier for people in the future to follow your repair.

Does pin 4 BLU_On/Off go high when switched out of standby. If it does then what voltages do you have on pins 1 to 16 of ICD801

[seve91]

Re: Samsung 32" power supply BN44-0351B no backlight

ok here you are:
http://imgur.com/fVgnZDS
http://imgur.com/fOE2XLH
http://imgur.com/aVTshVM

Model of the PSU is BN44-0351B

[attainteddragon]

Re: Samsung 32" power supply BN44-0351B no backlight

pictures of the entire back of the tv and a pic of the ps, to start with.

[seve91]

Hi everyone,
got this TV with no backlight.
Soldered a 1k resistor between pin 16 and 18 of CNM801 and measured all the voltages.
Seems all ok, but in the drive block output i don't have high voltage for the backlight.
In fact the TV power on correctly, can hear the sound and can see that the panel is working if i put a torch in front of it.

How to troubleshoot the backlight? Thanks