Samsung LN32B360C5DUZA Stopped turning on.

[ʞɐǝɹɟ]

I have a Samsung LN32B360C5DUZA that recently stopped turning on. I found a thread about various problems with the TV, and opened it up. I spotted 1 blown capacitor, and pulled it, but then saw a few test to do, so I want to get some more information before I order the capacitor, and find out I need more.

The power board is sitting on my workbench, when I plug it in, I get 450Vdc at CP815, but CM852 has been pulled from the board, and there is nothing but power connected, no switches, or TV, would that make the voltage read high like that, or should I also go ahead, and check everything else? This tv has the BN44-00289B power board in it.

I am trying to learn to all about electronics from home/DIY, so I have a general grasp of things, but not any real knowledge yet.

[budm]

Re: Samsung LN32B360C5DUZA Stopped turning on.

1) Are you sure you are getting 450VDC measured between the two legs of that CP815? That cap is rated at 450VDC, the Voltage on that cap should be between 380 ~ 400V range. If it is truly at 450VDC, do not try to run the board any more until the cause is found.
2) What did you use for GND ref for the meter?
3) Which cap is blown?
4)What Voltages do you have on all the pins of the connector that goes to the main board? We need the name of each pin and follow by the Voltage reading for each pin.
5) You can read schematic, right?
6) Upload good clear pictures of YOUR board.

[ʞɐǝɹɟ]

Re: Samsung LN32B360C5DUZA Stopped turning on.

1) Are you sure you are getting 450VDC measured between the two legs of that CP815? That cap is rated at 450VDC, the Voltage on that cap should be between 380 ~ 400V range. If it is truly at 450VDC, do not try to run the board any more until the cause is found.
2) What did you use for GND ref for the meter?
3) Which cap is blown?
4)What Voltages do you have on all the pins of the connector that goes to the main board? We need the name of each pin and follow by the Voltage reading for each pin.
5) You can read schematic, right?
6) Upload good clear pictures of YOUR board.

1) My bad, I meant 400Vdc at CP815, well 392Vdc to be precise, I was looking at something else, and typed 450 by mistake.

2) I checked CP815 using the capacitors cathode leg

3) CM852 is blown, the top was opened up, and the inside gook was all over the sides, and top, which is a 1200uF 10Vdc capacitor.

4) I will check those tomorrow when I get a chance to go to my shop, and tinker.

5) Somewhat, I know what most of the symbols mean, and can follow a connection on a schematic.

6)

[ʞɐǝɹɟ]

Re: Samsung LN32B360C5DUZA Stopped turning on.

Using 16 as a GND,

Pin
2 5.29V
4 13.3V
7 5.3V
8 5.3V
10 13.3V
11 13.3V
12 2.095V
13 5.3V

Pins not listed, had no voltage. I followed the schematic to get the pin numbers, 16 being the one closest to the top of the board.

[Davi.p]

Re: Samsung LN32B360C5DUZA Stopped turning on.

How do you have written your nickname upside down??!

[budm]

Re: Samsung LN32B360C5DUZA Stopped turning on.

Using 16 as a GND,

Pin
2 5.29V
4 13.3V
7 5.3V
8 5.3V
10 13.3V
11 13.3V
12 2.095V
13 5.3V

Pins not listed, had no voltage. I followed the schematic to get the pin numbers, 16 being the one closest to the top of the board.

You did not put down the pin name as I requested: 'We need the name of each pin and follow by the Voltage reading for each pin.'
Please follow the instruction.

[ʞɐǝɹɟ]

Re: Samsung LN32B360C5DUZA Stopped turning on.

You did not put down the pin name as I requested: 'We need the name of each pin and follow by the Voltage reading for each pin.'
Please follow the instruction.

What do you mean pin "name"? They are numbered 1-16, not named. Do you mean what each pin is supposed to be according to the schematics?

[vinceroger69]

Re: Samsung LN32B360C5DUZA Stopped turning on.

yes like pin 1 ps-on 5v
pin 3 bl-on 5v
etc etc

[budm]

Re: Samsung LN32B360C5DUZA Stopped turning on.

Pin names are printed right on the board to tell you what each pin is for.

[ʞɐǝɹɟ]

Re: Samsung LN32B360C5DUZA Stopped turning on.

PWR-ON/OFF Nothing
STBY 5.29v
GND Nothing
13V(S) 13.3v
GND Nothing
GND Nothing
5.3V 5.3v
5.3V 5.3v
GND Nothing
13V(M) 13.3v
13V(M) 13.3v
INVERTOR-ON/OFF 2.095v
E-PWM 5.3v
DLT_5V Nothing
SYNC Nothing
GND Nothing

[budm]

Re: Samsung LN32B360C5DUZA Stopped turning on.

PWR-ON/OFF Nothing
STBY 5.29v
GND Nothing
13V(S) 13.3v
GND Nothing
GND Nothing
5.3V 5.3v
5.3V 5.3v
GND Nothing
13V(M) 13.3v
13V(M) 13.3v
INVERTOR-ON/OFF 2.095v
E-PWM 5.3v
DLT_5V Nothing
SYNC Nothing
GND Nothing

1) That must be an error in measurement to have 0V on that power on/off pin, it must have at least 2VDC right now otherwise you will not have closed to 400VDC on the main cap, and will not have switched 13VDC either, so it must be just measurement error.
2) Other Voltages and control signals are OK but not 100% sure if DLT_5V (Inverter circuit failure signal to main board) 0V = No Error or not.
3) The fuse FM802S for supplying the PFC Voltage to the inverter circuit is good?
4) Check the VCC pin of the Inverter PWM IC UI801 (SEM2006) pin 14 to see if the VCC Voltage is present or not. Use Black probe to the GND pin of the IC or the negative leg of the main filter cap as the circuit GND for the hot side.
5) Check the Enable signal on pin 16 of the IC UI801 to see if it is present or not, it should be >2VDC.

4) Do you see the backlights even flash on for seconds at all.

[ʞɐǝɹɟ]

Re: Samsung LN32B360C5DUZA Stopped turning on.

1) That must be an error in measurement to have 0V on that power on/off pin, it must have at least 2VDC right now otherwise you will not have closed to 400VDC on the main cap, and will not have switched 13VDC either, so it must be just measurement error.
2) Other Voltages and control signals are OK but not 100% sure if DLT_5V (Inverter circuit failure signal to main board) 0V = No Error or not.
3) The fuse FM802S for supplying the PFC Voltage to the inverter circuit is good?
4) Check the VCC pin of the Inverter PWM IC UI801 (SEM2006) pin 14 to see if the VCC Voltage is present or not. Use Black probe to the GND pin of the IC or the negative leg of the main filter cap as the circuit GND for the hot side.
5) Check the Enable signal on pin 16 of the IC UI801 to see if it is present or not, it should be >2VDC.

4) Do you see the backlights even flash on for seconds at all.

Nothing happened before with the press of the power button. No backlight flash, or anything.
CM852 Has not been replaced, and is bad, and pulled, which I think would account for the first. I am trying to determine if I will need other parts before I order it, so I am not making multiple orders, and paying shipping multiple times for just a few parts each time.


All fuses are good, pulled, and checked, not checked on board.

[budm]

Re: Samsung LN32B360C5DUZA Stopped turning on.

You should replace other caps in the cold side as well, bad caps can look normal but it can have high ESR. Since that CM852 is the main filter cap for the 5V STBY supply, you need to at least replace that cap first before going further. Right now it is not blowing any fuses so that is a good sign.
Don't you have any other spare caps at all?

[ʞɐǝɹɟ]

Re: Samsung LN32B360C5DUZA Stopped turning on.

You should replace other caps in the cold side as well, bad caps can look normal but it can have high ESR. Since that CM852 is the main filter cap for the 5V STBY supply, you need to at least replace that cap first before going further. Right now it is not blowing any fuses so that is a good sign.
Don't you have any other spare caps at all?

Nope, no spare caps. I will try to find one locally, or with cheap shipping, and low ESR, then report back after I replace it.

[ʞɐǝɹɟ]

Re: Samsung LN32B360C5DUZA Stopped turning on.

After replacing CM852 the TV now functions properly. Thanks for your help.