Samsung 2493 HM issue

[zulururu]

Hi,

I Just discovered that forum a couple days ago and there seems to be very knowledgeable people and a lots of information here !
I have a Samsung syncmaster 2493HM which was working fine until a few days ago, then suddenly the backlight started to go dim and a few seconds later, the monitor was black.
Now, when I turn on the monitor, the blue LED light comes on and stays on solid, never go to sleep (never amber or blinking) and the screen remains blank. Even with a flashlight I don't see any walpaper.
I looked at some similar post in the forum and didn't find any solution yet. I am very new at this.
I didn't find any obvious damaged caps, the fuses seems to be good, I checked the 2 voltage regulators on the logic board as per this thread
https://www.badcaps.net/forum/showth...ghlight=2493hmand I find the same results as Werthles:
"On the red circled chip i got 5.22, 0, 5.22 on the three pins starting from the top in the image. On the yellow circled chip i got 2.52, 0, 3.31 on the three pins starting from the top in the image."

Attached are pics from my different boards.
Can somebody help me please ??

[alexanna]

Re: Samsung 2493 HM issue

I do see 2 Caps that looked bulged.
On the left side of the power supply there is a connector, I can read that some pin are 24Volts,There should be some pins labeled on/off or p/on and one that is marked dim,and some grounds.
With a signal going to the monitor what voltages do you read on these pins?

[zulururu]

Re: Samsung 2493 HM issue

Hi Alexanna,

Thanks for your quick reply, on the left hand side connector there are pins labelled +24v, Gnd, SOS, BL, A_DIM.
Do I have to plug all the cards together to measure these voltages ?

[alexanna]

Re: Samsung 2493 HM issue

It would be best to have everything connected,Please be careful not to short anything to ground.

[zulururu]

Re: Samsung 2493 HM issue

I have:
+24v:1.2v
Gnd: 0v
SOS:0.13v
BL:0.13v
Adim:0.06v

[alexanna]

Re: Samsung 2493 HM issue

Whats the number of th power supply BNxxxxxxx?

[zulururu]

Re: Samsung 2493 HM issue

I am working tonight, so I don't have the board in front of me but according to the picture it's BN44-00195A.
Thank you very much for your time !!!

[zulururu]

Re: Samsung 2493 HM issue

Apparently this Power supply is also used on the samsung 245BW and 245B...
http://cgi.ebay.com/Samsung-2493HM-2...-/170619669136

[alexanna]

Re: Samsung 2493 HM issue

Apparently this Power supply is also used on the samsung 245BW and 245B...
http://cgi.ebay.com/Samsung-2493HM-2...-/170619669136

That's what I thought.
There are 3 threads open on this P/S now.
On the connector going to the logic board, there should be a p/s on and a 5.3v. Pins
I don't know for sure if 24v is on that connector but if it is measure it.
What voltages do you measure?
Do the 2 capacitors near that connector appear domed to you?

[zulururu]

Re: Samsung 2493 HM issue

Should I leave the logic board unplug for the measurement ? I will check that tomorrow and let you know...
As I recall the 2 caps top seems flat view from the side.
Thanks again !

[alexanna]

Re: Samsung 2493 HM issue

Should I leave the logic board unplug for the measurement ? I will check that tomorrow and let you know...
As I recall the 2 caps top seems flat view from the side.
Thanks again !

Every thing hooked up

[zulururu]

Re: Samsung 2493 HM issue

Here is the measurements I did on the connectors going to the logic board:
With the monitor switched ON/Switched Off:

24v Det: 0.12v/0.01v
pwm dim: 0.06v/0v
Brt_ctl:0.06v/0v
A_dim:0.13v/0v
Bl_en:0.11v/0v

NC:0v/0v
NC:0v/0v

5.3v:0.26v/0v
5.3v:0.26v/0v
GND:0/0v
GND:0/0v
GND:0/0v
+18v:0v/0v
+18v:0v/0v
+18v:0/0v
GND:0v/0v
GND:0v/0v
GND:0v/0v
+5v Micom: 5.21v/5.21v
Power EN:3.22v/0v

[alexanna]

Re: Samsung 2493 HM issue

The Power EN 3.2V is missing,that is what will request the 5.3V and 24 V. to turn on
at this point I am not sure why its missing

[dumpystig]

Re: Samsung 2493 HM issue

Hmm... that board really is dead

[zulururu]

Re: Samsung 2493 HM issue

Well, I have 3.2v on the Power en when the monitor in turned On, and 0v on the power EN when the monitor is turned off.
Maybe my last post is not really clear:
Power EN:3.22v/0v means monitor On:3.22v, monitor Off:0v

[alexanna]

Re: Samsung 2493 HM issue

Well, I have 3.2v on the Power en when the monitor in turned On, and 0v on the power EN when the monitor is turned off.
Maybe my last post is not really clear:
Power EN:3.22v/0v means monitor On:3.22v, monitor Off:0v

Thats a good thing,There is another thread tats describes you problem with some more things to test.If you can't find it i will try to add a link

https://www.badcaps.net/forum/showthread.php?t=15796

[zulururu]

Re: Samsung 2493 HM issue

Thanks for the link !
I'll try to do some more troubleshooting

[jetadm123]

Re: Samsung 2493 HM issue

In the link that alexanna provided, post #6, one of the pins on the connector is labeled S_B. I believe this is the standby voltage. It should read approx. 5V. Are you at least reading that?

[alexanna]

Re: Samsung 2493 HM issue

I could possibaly be wrong, but i think the pin Micom is the standby voltage?

[zulururu]

Re: Samsung 2493 HM issue

The input connector labelled Micom is labelled S_B on the output connector of the power supply and yes I have 5.21V on that one