Samsung LE37A556P1F Flashing red light

[Jasgriff]

Hi All,

Can anyone help me work our what I need to do next.....

I bought this tv and it was turning itself off after a minute or two. I took it apart and noticed that the were a few bad capacitors on the board. I changed all of these capacitors with ones of the same value and then hoping that I had fixed the problem I put it all back together.

Unfortunately the problem was still there. I then decided to disconnect the touch panel on the tv incase that was faulty and causing the TV to turn off but This still didnt help.

When the TV did turn on the screen came on as it should with the No Signal message before it turned itself off.

Now the TV wont turn on at all. The red light just flashes 4 times and then goes to solid red.

I have attached a pic of the board and the board model number.

I am sure with your help I can finally get this up and running

[TechAMP]

Re: Samsung LE37A556P1F Flashing red light

Hello people. My Samsung LE37M86BD TV has got black screen. The power supply provides all the voltages needed to, but it will not turn on, even though the "Power Button" you can see that it is on! There comes a glimpse of the backlight for a few milliseconds and then disappears.
Is there anyone who knows about this?

Thank you in advance.

[TechAMP]

Re: Samsung LE37M86BD wont turn the screen!

Hello people. My Samsung LE37M86BD TV has got black screen. The power supply provides all the voltages needed to, but it will not turn on, even though the "Power Button" you can see that it is on! There comes a glimpse of the backlight for a few milliseconds and then disappears.
Is there anyone who knows about this?

Thank you in advance.

[retiredcaps]

Re: Samsung LE37A556P1F Flashing red light

I bought this tv and it was turning itself off after a minute or two. I took it apart and noticed that the were a few bad capacitors on the board. I changed all of these capacitors with ones of the same value and then hoping that I had fixed the problem I put it all back together.

1) Did you replace all the capacitors or just the obviously bad ones?

2) What brand and series did you use for replacements? For example, Panasonic is the brand and FM is the series.

3) See my standard answer regarding replacing capacitors at

https://www.badcaps.net/forum/showpo...84&postcount=3

4) Do you have a multimeter and are you familiar with measuring DC voltages?

5) If you have a multimeter, please post a picture of it.

6) We will need clear focused pictures to suggest test points. The ones you posted are way too grainy to make out any detail. We will also need a picture of the main board.

[retiredcaps]

Re: Samsung LE37A556P1F Flashing red light

Is there anyone who knows about this?

We need clear top down focused pictures of both sides of all your boards uploaded to this forum in order to suggest test points. Follow the instructions in my sig file below exactly.

[TechAMP]

Re: Samsung LE37M86BD wont turn the screen!

Thanks for the response! Her is som stuff to look at:

[Jasgriff]

Re: Samsung LE37A556P1F Flashing red light

1) Did you replace all the capacitors or just the obviously bad ones?

All of the capacitors were replaced except for the massive one.

2) What brand and series did you use for replacements? For example, Panasonic is the brand and FM is the series.

5 x 35v 1000uf 105c (SD CD263)
1 x 10v 3300uf 105c (KY)
1 x 10v 2200uf 105c (FR 1390F)
2 x 25v 1000uf 105c (SD CD263)

I have to hold my hands up they are the first I could get my hands on so I can imagine they might not be favoured brands.

3) See my standard answer regarding replacing capacitors at

https://www.badcaps.net/forum/showpo...84&postcount=3

I will have a read up on this now.

4) Do you have a multimeter and are you familiar with measuring DC voltages?

Yes, i have some knowlege measuring DC Voltages.

5) If you have a multimeter, please post a picture of it.

Yes I recently purchased a UNI-T 132A. I have attached a picture of it below.

6) We will need clear focused pictures to suggest test points. The ones you posted are way too grainy to make out any detail. We will also need a picture of the main board.

Sorry for the poor picture I didnt have my camera to hand. I have attached a picture of the exact same board that I found on on the net which also has the capacitors values written on them. I will have to attach the bottom on a second post as this wont attach in this one.

Thanks again for your help...

[Jasgriff]

Re: Samsung LE37A556P1F Flashing red light

Here is a picture of the underside of the board.

The mainboard is an MT8226_EMMA BN41-00974B I will work on trying to get an image of this for you.

[TechAMP]

Re: Samsung LE37M86BD wont turn the screen!

We need clear top down focused pictures of both sides of all your boards uploaded to this forum in order to suggest test points. Follow the instructions in my sig file below exactly.

Thanks for the response! Her is som stuff to look at:

[Jasgriff]

Re: Samsung LE37A556P1F Flashing red light

Right I have had another play with this TV to try and give you as much info as possible.

If you look at connector 1 on the attached Pic The pins are labelled and tested as follows.

NC - N/A
ADIM? - Untested
BL - Untested
NC - N/A
GND - Tested OK
GND - Tested OK
GND - Tested OK
GND - Tested OK
GND - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK

Connector 2 Left to right

BLU - Untested
Adim - Untested
PWM - Untested
GND - Tested OK
+5v - Tested OK

I also tried.....

Connector 1 Connected
Connector 2 connected
connector 3 connected

Screen remains blank and the red standby light flashes a few times then goes off. when I press buttons on the remote the stanbylight flases as I would imagine it would during normal operation. If I press the poer button on the remote control the standby light changes to solid red again as I would imagine it does during normal operation.

Connector 1 Connected
Connector 2 Disconnected
Connector 3 Connected

The backlight come on and the TV behaves exactly as mentioned in the scenario above.

Connector 1 Connected
Connector 2 Connected
Connector 3 Disconnected

Nothing at all.

Not really sure where to go next?

[Jasgriff]

Re: Samsung LE37A556P1F Flashing red light

Ok just tried something else.

I am guessing that PWM on connector 2 on the power supply need a must be the a trigger that the mainboard sends to the PSU to tell it to turn everything on.

I tested this by connecting up connector 1 and connector 2 the on the mainboard I found the pin that would supply the power supply with a logic signal and tested it with a multimeter. It seems to be giving out +3.1v.

Should this voltage be higher to tell the power supply to turn on?

[tom66]

Re: Samsung LE37A556P1F Flashing red light

Do you have sound when the TV is turned on?

Have you got all the inverter power cables properly secured; including the cable that is sometimes present going from T-con to power supply?

[Jasgriff]

Re: Samsung LE37A556P1F Flashing red light

Do you have sound when the TV is turned on?

Have you got all the inverter power cables properly secured; including the cable that is sometimes present going from T-con to power supply?

No sound through any combination of cables that I have tried.

Just tried taking the connectors off and reconnecting them nice and secure but there is still no sound.

[py3m4n]

Re: Samsung LE37A556P1F Flashing red light

My response is to Jasgriff. Why has TechAMP ambushed Jasgriffs thread, lol.

Sounds like you might have a corrupted eeprom on the mainboard. Was it caps on the power supply that you replaced? I know with the LE40R88BD series that this is quite common (seen it myself) where after replacing the capacitors on the power supply the eeprom is corrupted on the mainboard the first time you boot the T.V. All that said, I am not sure if this will apply to your model but it can't do any harm to look into it.

[retiredcaps]

Re: Samsung LE37A556P1F Flashing red light

There comes a glimpse of the backlight for a few milliseconds and then disappears.

1) Hookup a DVD source playing a movie. Plug it into the TV. In dark room, can you see the DVD playing without the backlight on? Try shining a flashlight on it. Is there sound?

2) Circled in red are some ICs. What is the part number?

3) The pics are good, but resolution is a bit small on the inverter board. I circled what I think are SMD fuses. A fuse should be marked as something like F100 on the pcb.

A single blown fuse could be causing the backlight not to come on. Check them with your multimeter. A good fuse should measure less than 1.0 ohms.

[retiredcaps]

Re: Samsung LE37A556P1F Flashing red light

24V - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK

We prefer the actual readings. I have no idea of your background and/or level of knowledge so "OK" means nothing.

If you wrote instead

24V - measured 24.01V

then, I would agree the voltage is OK.

PS. We want pictures of your board, not some stock photo. A stock photo does not show hot spots, glue turned conductive, burnt resistors, etc.

[budm]

Re: Samsung LE37A556P1F Flashing red light

Connector 1 these signals go to the Inverter board
The ADIM, BL signals are passed through from Connector 2 which connected to the main board.
NC - N/A
ADIM? - Untested: Backlights dimming voltage (0=min, 5v = max brightness)
BL - Untested: Backlights on
NC - N/A
GND - Tested OK
GND - Tested OK
GND - Tested OK
GND - Tested OK
GND - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK

Connector 2 Left to right

BLU - Untested: Backlights ON signal from the main board (3.3~5v = ON)
Adim - Untested: This pin gets the 0~5vdc Dimming control signal from Main board
PWM - Untested: This pin is not used, it is the Pulse Width Modulation signal (another method of Dimming the backlights) from the main board for Dimming control, is not used on this set.
GND - Tested OK
+5v - Tested OK: 5Vdc to the main board

So you need to have the BL 3.3~5VDC on this pin for the Inverter to come on, you already have the 24vdc, you just do not have the ON signal per your post.

[Jasgriff]

Re: Samsung LE37A556P1F Flashing red light

My response is to Jasgriff. Why has TechAMP ambushed Jasgriffs thread, lol.

Sounds like you might have a corrupted eeprom on the mainboard. Was it caps on the power supply that you replaced? I know with the LE40R88BD series that this is quite common (seen it myself) where after replacing the capacitors on the power supply the eeprom is corrupted on the mainboard the first time you boot the T.V. All that said, I am not sure if this will apply to your model but it can't do any harm to look into it.

Hi Py3m4n,

I changed all of the capacitors on the cold side of the board and it came on a couple of times for a few seconds then straight off sometimes you could hear a high pitched noise or scream coming from the mainboard by the sound of it.

When I get back from work I will start to check the mainboard I will also take some good pics of it so that you can point me in the right direction of what to check.

Ta for your help.

[Jasgriff]

Re: Samsung LE37A556P1F Flashing red light

We prefer the actual readings. I have no idea of your background and/or level of knowledge so "OK" means nothing.

If you wrote instead

24V - measured 24.01V

then, I would agree the voltage is OK.

PS. We want pictures of your board, not some stock photo. A stock photo does not show hot spots, glue turned conductive, burnt resistors, etc.

Sorry,

24V - 24.3v
24V - 24.3v
24V - 24.3v
24V - 24.3v
24V - 24.3v

I will sort out some better pictures when I return home from work. I used those stock photos just to see if there was anything thing that could be tested whilst I had the day off twiddling my thumbs

Cheers for your help.

[Jasgriff]

Re: Samsung LE37A556P1F Flashing red light

Connector 1 these signals go to the Inverter board
The ADIM, BL signals are passed through from Connector 2 which connected to the main board.
NC - N/A
ADIM? - Untested: Backlights dimming voltage (0=min, 5v = max brightness)
BL - Untested: Backlights on
NC - N/A
GND - Tested OK
GND - Tested OK
GND - Tested OK
GND - Tested OK
GND - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK
24V - Tested OK

Connector 2 Left to right

BLU - Untested: Backlights ON signal from the main board (3.3~5v = ON)
Adim - Untested: This pin gets the 0~5vdc Dimming control signal from Main board
PWM - Untested: This pin is not used, it is the Pulse Width Modulation signal (another method of Dimming the backlights) from the main board for Dimming control, is not used on this set.
GND - Tested OK
+5v - Tested OK: 5Vdc to the main board

So you need to have the BL 3.3~5VDC on this pin for the Inverter to come on, you already have the 24vdc, you just do not have the ON signal per your post.

While testing connector 1 with connector 2 and 3 plugged into the mainboard I get the following...

Adim = 0v
BL = 0.1v

This is in the on state where if connector 1 was hooked up it would give me a completely blank picture.

With connector 1 and 3 connected I tested connector 2 on the mainboard.

BLU = 0.1v
Admin = 0v
PWM = 3.2v

Ta for the help with the pins this will help when I am do a little more testing tonight.