Samsung T240HD won't turn on

[phx777]

was using it last night as usual then it just turned off, there werent any strange sounds or anything. it just went black and the power indicator light faded away. now it doesnt turn on, the power cord works fine, and I've tried turning it on with the remote as well.

is this because of a faulty power board? does anyone turn how to actually disassemble this?

thanks!


EDIT: I managed to get it open, for people wondering how:
there are two visible screws that you have to undo first, then you must take off the stand. (this is where I got stuck on earlier). While the monitor is facing down, what you want to do is lift the stand itself really hard while pulling on it.
after the stand comes off there are two more screws to be undone. then you have to use a flat head screw driver to ply off all the tabs on all sides. I worked my way around, there were a lot of loud popping noises. and I broke one of the tabs. but now it's open.


I also managed to take off the power board, it's got some solid white substance everywhere, is this suppose to be here? or is this why it broke?

edit2: turns out it's suppose to be there. so... any way to test if this thing still works or not?

[ben7]

Re: Samsung T240HD won't turn on

was using it last night as usual then it just turned off, there werent any strange sounds or anything. it just went black and the power indicator light faded away. now it doesnt turn on, the power cord works fine, and I've tried turning it on with the remote as well.

is this because of a faulty power board? does anyone turn how to actually disassemble this?

thanks!


EDIT: I managed to get it open, for people wondering how:
there are two visible screws that you have to undo first, then you must take off the stand. (this is where I got stuck on earlier). While the monitor is facing down, what you want to do is lift the stand itself really hard while pulling on it.
after the stand comes off there are two more screws to be undone. then you have to use a flat head screw driver to ply off all the tabs on all sides. I worked my way around, there were a lot of loud popping noises. and I broke one of the tabs. but now it's open.


I also managed to take off the power board, it's got some solid white substance everywhere, is this suppose to be here? or is this why it broke?

edit2: turns out it's suppose to be there. so... any way to test if this thing still works or not?

You said the power indicator faded away? Strange!

Did you check the obvious things like, fuses, and connectors?

[phx777]

Re: Samsung T240HD won't turn on

well, the indicator light usually always fades away. I assume it's because some electricity still lingers inside the monitor when you yank out the power.

what's the most common cause for a monitor not turning on? I think I'm just gonna buy a power board, swap it, and return it if that doesn't fix it.

[selldoor]

Re: Samsung T240HD won't turn on

Picture is not good enough for troubleshooting - too much shadow and a bit of shake.
Do you have a multimeter and soldering equipment .
As ben says first check the two fuses one white ceramic and a small green torpedo.

[phx777]

Re: Samsung T240HD won't turn on

Picture is not good enough for troubleshooting - too much shadow and a bit of shake.
Do you have a multimeter and soldering equipment .
As ben says first check the two fuses one white ceramic and a small green torpedo.

I've just checked the 2 fuses by using a battery and a light bulb, they both work. what's this green torpedo you speak of? the 2 fuses are both white.

I'll try to get a better picture.

[ben7]

Re: Samsung T240HD won't turn on

I've just checked the 2 fuses by using a battery and a light bulb, they both work. what's this green torpedo you speak of? the 2 fuses are both white.

I'll try to get a better picture.

The green 'torpedo' is a fuse on the PSU. It is in the central area of the board, it looks like a resistor, but it is marked 'F301'

[phx777]

Re: Samsung T240HD won't turn on

The green 'torpedo' is a fuse on the PSU. It is in the central area of the board, it looks like a resistor, but it is marked 'F301'

just tested that, it works.

more picture:
http://imgur.com/a/P2Xr2

I noticed there was this one thingy on the back that's not connected, this isnt the problem right?

[ben7]

Re: Samsung T240HD won't turn on

just tested that, it works.

more picture:
http://imgur.com/a/P2Xr2

I noticed there was this one thingy on the back that's not connected, this isnt the problem right?

I don't think that would be the problem. It is in the invertor circuit, and I'm guessing that it is two, or 4 mosfets in one package. It is common to see SMD mosfets or voltage regulators with a lead clipped off like that - the lead is always in the middle, and it almost always connects to the big one on the other side, which spreads the heat.

[selldoor]

Re: Samsung T240HD won't turn on

Please can you post the pictures using manage attachments.


Do you have a multimeter and soldering equipment .

Only so many tests you can do with a battery and a bulb.

[phx777]

Re: Samsung T240HD won't turn on

Please can you post the pictures using manage attachments.


Do you have a multimeter and soldering equipment .

Only so many tests you can do with a battery and a bulb.

I can obtain a multimeter in a day's time, and I have soldering equipment.
what else should I test?

and thanks for all the help so far!

[selldoor]

Re: Samsung T240HD won't turn on

Ok - Have you now got a multimeter and can you transfer your pictures from the offsite
and post them using manage attachments

[phx777]

Re: Samsung T240HD won't turn on

Ok - Have you now got a multimeter and can you transfer your pictures from the offsite
and post them using manage attachments

yes I got a multimeter now.

and how come I cant edit my thread anymore?
edit: I think it's cuz the thread is too old... anyway, I uploaded the pictures here. If a mod sees this, feel free to remove the imgur links from above. thx

My Current Problem:
My Samsung T240HD turned off by itself about a month ago. I bought another power board off ebay thinking it was the defective part. I swapped it out and my electricity tripped. Great, defective replacement.
Now I'm thinking, could it be another part that's broken? How can I test if it is the power board that's broken or the main board. Or some other part?

thanks!

attachment is picture of my "broken" board, I've tested the fuses and the caps on it, seems to be working. the last picture is a picture of the main board which I have not tested/dunno how.

[Rtech]

Re: Samsung T240HD won't turn on

On the bottom right of the Board is a list of what voltage each pin should have on it,when it is working properly.You need to plug the Board into the Mains..NO OTHER BOARDS..Set your meter to DC Volts and firstly test across the BIG Capacitor,the reading should be about 155-160Volts if you have a 110v Mains supply.BE VERY CAREFUL.The negative (normally Black lead)goes to the pin on the cap on the same side as the stripe down the cap,and the other lead to the other pin.If you get that then measure between each pin and that connector near the lettering at the bottom,using the Black Lead on GND as shown on the lettering and the red on each ovf the other pins.

[phx777]

Re: Samsung T240HD won't turn on

On the bottom right of the Board is a list of what voltage each pin should have on it,when it is working properly.You need to plug the Board into the Mains..NO OTHER BOARDS..Set your meter to DC Volts and firstly test across the BIG Capacitor,the reading should be about 155-160Volts if you have a 110v Mains supply.BE VERY CAREFUL.The negative (normally Black lead)goes to the pin on the cap on the same side as the stripe down the cap,and the other lead to the other pin.If you get that then measure between each pin and that connector near the lettering at the bottom,using the Black Lead on GND as shown on the lettering and the red on each ovf the other pins.

I tested the big cap (marked red below), the voltage is at 160. I dont see the list you are speaking of.
should I also test the other caps marked in the attachment? is that all of them?

[Rtech]

Re: Samsung T240HD won't turn on

On your photo, Bottom right there is a list of Voltages that should be found on the Pins on the connector next to it.

[phx777]

Re: Samsung T240HD won't turn on

On your photo, Bottom right there is a list of Voltages that should be found on the Pins on the connector next to it.

here it is enlarged.
I'm not exactly sure what this means... sorry

[selldoor]

Re: Samsung T240HD won't turn on

OK With your meter on VDC 20 put the black pin on pin 4 and with the red probe touch
the other pins and report the results.
Board needs to be plugged in to the mains. Still take care although you are measuring low voltages parts of the board are still high.

[phx777]

Re: Samsung T240HD won't turn on

OK With your meter on VDC 20 put the black pin on pin 4 and with the red probe touch
the other pins and report the results.
Board needs to be plugged in to the mains. Still take care although you are measuring low voltages parts of the board are still high.

ok I tested the other 9 caps, only one of them was reading 10v all others are reading very close to 0. (see attachment).

just to make sure, I tested by putting the red lead on the + side (marked on the board) and black lead on the other side.

the power board is connected to the main board, the main board is connected to the LCD that is a pain to remove so I didnt bother with it.

[Rtech]

Re: Samsung T240HD won't turn on

The whole idea is to have the |POWER SUPPLY ONLY, not the other boards.

[selldoor]

Re: Samsung T240HD won't turn on

OK With your meter on VDC 20 put the black pin on pin 4 and with the red probe touch
the other pins and report the results.
Board needs to be plugged in to the mains. Still take care although you are measuring low voltages parts of the board are still high.

Not really getting through to you are we?
The above test is to be carried out with only the power supply plugged into the mains - no other boards for the moment.
The pins are on the connector CN2 in the same corner that the voltage list is