Samsung monitor 2493 HM steady blue light dead

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

There are 5 small electrolytics caps close by the SMPS ICB801S that should be check for ESR and capacitance, or just replace them if you do not have ESR/Capacitance meter.

Thanks again budm; i checked all those little caps and all of the others with my Cap Analyzer 88A and all check good ,
but i checked this SM resistor 104 that measures 4K it should be 100K next to C809 there is another 104 in same area that measure about 95K what is about right,i would post Board # of these SM resistors but they are hard to reed.

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

Thanks budm,what do you mean?bad stratup/running cap?you mean the IC is bad?

There are 5 small electrolytics caps close by the SMPS ICB801S that should be check for ESR and capacitance, or just replace them if you do not have ESR/Capacitance meter.

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

At this point the standby power supply is not running for sure, 10.6VDC is too low to run the IC, we need to get this running first.
So it can be bad stratup/running cap connected to the VCC pin is bad something inside the IC is bad.

Thanks budm,what do you mean?bad stratup/running cap?you mean the IC is bad?

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

At this point the standby power supply is not running for sure, 10.6VDC is too low to run the IC, we need to get this running first.
So it can be bad stratup/running cap connected to the VCC pin is bad something inside the IC is bad.

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

OK, what DCV do you have at 'STB' pin of the connector CN851? or you can measure it between the cap CB853 legs, you can do this with just the power supply by itself.
The standby power supply IC is ICB801S (STR-A6159) which you can also check to see if you have VCC Voltage at pin 2 (VCC) and GND pin 3.
Looking at the board, the 5.3V is a switched 5.3V and will not be present until PS-ON is present.
STBY pin is the Standby power supply output which should be present at all time as long as the AC is applied to the board.
Pictures provided by shopjimmy.

Thanks budm; Ok on CB853 2200uf legs have 00v,
on IC853s pin 2vcc to pin3 gnd =10.6v

also if i understand to have the 24v and 5.5v i have to put power supp back with the boards connected with the tv?thanks

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

OK, what DCV do you have at 'STB' pin of the connector CN851? or you can measure it between the cap CB853 legs, you can do this with just the power supply by itself.
The standby power supply IC is ICB801S (STR-A6159) which you can also check to see if you have VCC Voltage at pin 2 (VCC) and GND pin 3.
Looking at the board, the 5.3V is a switched 5.3V and will not be present until PS-ON is present.
STBY pin is the Standby power supply output which should be present at all time as long as the AC is applied to the board.
Pictures provided by shopjimmy.

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

In standby the DVC on the main filter will be around 165~170VDC, the PS-ON signal from the main board is present, the PFC Voltage booster (the DCV on the big cap will be close to 400VDC) and the 12V/24V SMPS will then start running, but if you do not have any standby Voltage then nothing will work until the standby Voltage is present.

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

Thanks budm, yes forward bias 0.207 and reverse OL off the board,
i did not try to power up after i cleaned the dry glue from all components,well i'm going to solder back Diode and power and check back,thanks.

Well budm i connected the power supply by itself to power and still no 24v or 5.3v.

i notice that CP 801 the big cat in the middle says on the board 380v and i check dc volts i get 167v only is this right?

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

I will have to look at the boards I have and give you the test point.
So right now just to be sure, you DO NOT have any DCV at any of the connector in the secondary that go to the Inverter board or the main board, correct?

'Forward Bias 0.217' Is that reading off the board? The reverse bias show OL?
Vf can be as low as 0.3 at 0.1A, but if it does not show resistance readings on BOTH direction, more likely it is OK.

Thanks budm, yes forward bias 0.207 and reverse OL off the board,
i did not try to power up after i cleaned the dry glue from all components,well i'm going to solder back Diode and power and check back,thanks.

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

I will have to look at the boards I have and give you the test point.
So right now just to be sure, you DO NOT have any DCV at any of the connector in the secondary that go to the Inverter board or the main board, correct?

'Forward Bias 0.217' Is that reading off the board? The reverse bias show OL?
Vf can be as low as 0.3 at 0.1A, but if it does not show resistance readings on BOTH direction, more likely it is OK.

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

So your board is BN44-00195? I cannot tell from your pictures.

Yes budm; also can you tell me if Diode 31DQ 06 Shchottky measurements
are right?

Forward Bias 0.217

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

So your board is BN44-00195? I cannot tell from your pictures.

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

Hi budm; it's me again,here are some pic,sorry if i don't know how to make them better but anyway, i inspected power supply,also i took out cap cn809
4pf 1KV and cleaned it and re-soldered it, as someone here suggested,
and also i took out Diode D8551 31DQ 06 8G and measured it in circuit 0.106 OL other side and measures the same out of the circuit 0.106 and OL the other,i think it's too low,most of the same size diodes that i have in my scrap measure 0.405,
what do you think? thanks


http://postimg.org/image/5gbku97f3/b9d9830f/


http://postimg.org/image/cfgwfh5dl/d4ea2831/

http://postimg.org/image/74jczgn6t/57edf293/

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

Yes i removed all glues, the pics of the other post of the boards are similar and there is no signs of burning or any thing that one can check with pics,besides my camera is not that good and i don't know how to edit better pics


https://www.badcaps.net/forum/showth...t=14483&page=2

Hi budm; it's me again,here are some pic,sorry if i don't know how to make them better but anyway, i inspected power supply,also i took out cap cn809
4pf 1KV and cleaned it and re-soldered it, as someone here suggested,
and also i took out Diode D8551 31DQ 06 8G and measured it in circuit 0.106 OL other side and measures the same out of the circuit 0.106 and OL the other,i think it's too low,most of the same size diodes that i have in my scrap measure 0.405,
what do you think? thanks





http://postimg.org/image/cfgwfh5dl/d4ea2831/

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

If you do not even have the standby Voltage when you are running the board by itself then yes your power supply board is bad. You are not going to get any 24V until you get the standby power supply working first and it is has to get the PS-ON to turn on the the PFC Voltage booster circuit and the 24V SMPS circuit, the 24V power supply needs the boosted Voltage to run.
Did you remove ALL the glues? How about the pictures of your board?

Yes i removed all glues, the pics of the other post of the boards are similar and there is no signs of burning or any thing that one can check with pics,besides my camera is not that good and i don't know how to edit better pics


https://www.badcaps.net/forum/showth...t=14483&page=2

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

If you do not even have the standby Voltage when you are running the board by itself then yes your power supply board is bad. You are not going to get any 24V until you get the standby power supply working first and it is has to get the PS-ON to turn on the the PFC Voltage booster circuit and the 24V SMPS circuit, the 24V power supply needs the boosted Voltage to run.
Did you remove ALL the glues? How about the pictures of your board?

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

You can run the power supply board by itself to test the STANDBY power supply to see if that one is working or not first, if it does, then hook the board back together to test the Voltages on the connectors after the power switch is activated.

Hi budm; i've taken out the power supply and connected it to power without any boards connect and checked volts on connections to the main board and have no 24v or any other voltage and the same to connect to invert-er board
nothing at all, i guess the power supply is bad i could suspect resonant Mode Controller MC33067P but i'm not sure, thanks

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

You can run the power supply board by itself to test the STANDBY power supply to see if that one is working or not first, if it does, then hook the board back together to test the Voltages on the connectors after the power switch is activated.

[ivtec]

Re: Samsung monitor 2493 HM steady blue light dead

So what DCV do you have on the connector of the power supply board and the inverter board (inverter board connector has pin labels for each pin)?
Power supply board is BN44-00195? Did you also remove all the glues?

Thanks i did not check any voltage yet,just checked some components but without power, it's not easy to keep boards in place and plugged,we have to flip the board and remove boards to access voltages points on the boards.i will try to measure v and post voltages,thanks

[budm]

Re: Samsung monitor 2493 HM steady blue light dead

So what DCV do you have on the connector of the power supply board and the inverter board (inverter board connector has pin labels for each pin)?
Power supply board is BN44-00195? Did you also remove all the glues?