Samsung Syncmaster 223BW - dead as a rock

[azza]

Re: Samsung Syncmaster 223BW - dead as a rock

Hi guys i am having a similar problem with a samsung 223bw, i started off with the typical flickering screen and having to turn the monitor on and off a few times before it would work propperly and one day the screen would just not turn on at all and the blue power light would just flash on and off and in a moment of stress and madness i pushed the power button on and off loads of times anyway i have changed the "bad caps" but when i turn the monitor on now the power light flashes ever so slightly once every 5 seconds or so not how it used to and the screen still does not turn on so was wondering if it is worth changing all the rest of the caps on the power board or could i have damaged the power button? if anyone could point me in the right direction i will be most greatful thanx

Azza

[PlainBill]

Re: Samsung Syncmaster 223BW - dead as a rock

Hi guys i am having a similar problem with a samsung 223bw, i started off with the typical flickering screen and having to turn the monitor on and off a few times before it would work propperly and one day the screen would just not turn on at all and the blue power light would just flash on and off and in a moment of stress and madness i pushed the power button on and off loads of times anyway i have changed the "bad caps" but when i turn the monitor on now the power light flashes ever so slightly once every 5 seconds or so not how it used to and the screen still does not turn on so was wondering if it is worth changing all the rest of the caps on the power board or could i have damaged the power button? if anyone could point me in the right direction i will be most greatful thanx

Azza

There is little chance that you damaged the power button. There are a number of possible problems at this point.

1. Check the orientation of the caps you replaced. You wouldn't be the first person to put a cap in backwards.

2. You might have bridged two points when soldering. Again, it wouldn't be the first time that happened.

3. What brand and series of caps did you use? Very important - general purpose caps will not last long, and may not work at all.

4. There are several of the smaller caps that can fail and create the problem you describe. For that reason I ALWAYS suggest replacing all caps (with the possible exception of the large one).

PlainBill

[azza]

Re: Samsung Syncmaster 223BW - dead as a rock

Thankyou for the reply i am pretty sure i put the caps in the right way but will double check and make sure i havent bridged them, i am led to believe the replacement caps are made by panasonic but i am unsure as i brought them from ebay (maybe a mistake??) i will now go and replace all the smaller caps see if that fixes my problem i cant check to see if they are working correctly as i dont own a multimeter. Thankyou again for your help

[ndlm]

Re: Samsung Syncmaster 223BW - dead as a rock

Hi guys,
I have the same problem like Scenic. My 223BW won't power on.
Voltage regulators appear fine (1.8V, 3.3V and 5V), so that rules out power board malfunction.
Here's what I think that looks suspicious ( i will use Scenic's pic, since i don't have a decent camera):
1. Power button - goes only to 1.8V
Some people confirmed that there should be 3V on the button, that makes sense. That's the way it is drawn on the schematic.
However, i've traced the button pin to 1.8V through a pullup - instead of 3.3V.
2. No 5V on the LVDS connector

Is the schematic wrong?
Please help, I've been banging my head for days.

[budm]

Re: Samsung Syncmaster 223BW - dead as a rock

Do you have the schematics for me to look at?

[ndlm]

Re: Samsung Syncmaster 223BW - dead as a rock

Here it is:

http://linfotech.co.uk/schematics/Sa...ng%20223BW.pdf

[MDOC]

Re: Samsung Syncmaster 223BW - dead as a rock

The board pix you put up (it being someone else's board) is not the same board as the one pictured in the Samsung service manual. If Scenic's board is the board you have, you're looking at the wrong schematic.

I have the same board as the one in the manual, and it is very different from Scenic's board.

[ndlm]

Re: Samsung Syncmaster 223BW - dead as a rock

Damn. I overlooked that.
But, generally speaking, should I have 3V on the button and LEDs?

[MDOC]

Re: Samsung Syncmaster 223BW - dead as a rock

The schematic is incomplete--it doesn't show the function PCB or the switch. It doesn't even show the IP board.

(Regardless of what some say here about the reasons the IP board isn't included in the manual ["different boards are used in the same model monitors"], it is a disservice to technicians who expect "complete" schematics to be complete.)

I cannot answer your question unless I take apart my monitor and measure. All I can say is maybe it should be 3.3V, because [flippantly] LED_GREEN is tied to a processor or the pullup resistors for KEY1 and KEY2 connect to 3.3V (page 9-3). Who knows?

[cathary]

Re: Samsung Syncmaster 223BW - dead as a rock

Hello guys.

Does anyone figured out what's wrong with the logic board?
I had to recap the main PSU and after that the LCD is still "dead as a rock".
I measured all the voltage regulators 1.8V, 3.3V and 5V and they work fine.
But the 5V at the LVDS connector is still missing.

Any ideas or suggestions??

[Sparks88]

Re: Samsung Syncmaster 223BW - dead as a rock

one i managed to rescue had a faulty backlight which i found when i pulled on the wire and the end of the backlight came away, it had broken inside the end cap, replaced with led backilght strips and driver and it has been working well ever since.

[rjmusto]

Re: Samsung Syncmaster 223BW - dead as a rock

Hi Guys,
New member here with a problem 223BW. Mind if I bump in to this thread, as I can't start my own yet?

This one turns on ok and have checked through the various supplies and all ok (thanks to the info on this thread). No sign of blown caps.

However, it does not react to a DVI input, and on Analogue shows a picture fuzzed out like a TV with the line sync gone wrong. The menu windows display correctly though - see photo attached.

Any ideas, or is it a replacement control board?

Thanks,
Ralph

[cathary]

Re: Samsung Syncmaster 223BW - dead as a rock

Hello

I attached the service manual, maybe you'll find something to troubleshoot your problem.

But, first:
1. Check the LVDS cable or change it.
2. Check LVDS connectors for cold soldering or bad connection (both digital board and panel).
3. Check the 3.3V pinout on the LVDS cable.
4. Follow the steps described in the service manual.

[rjmusto]

Re: Samsung Syncmaster 223BW - dead as a rock

Hi cathary,
Thanks for the post and the manual.

Everything checks out ok, but still no good picture, so I think it is time to look for a replacement card.

Ralph

[Scenic]

Re: Samsung Syncmaster 223BW - dead as a rock

Hello guys.

Does anyone figured out what's wrong with the logic board?

Better late than never: the EEPROM holding the monitors firmware shits itself.
Flash the FW onto a new chip, replace it and it'll come back to life.

I've bought a refurbished replacement main board on ebay from china years and years ago because it was dirt cheap (10eur shipped or something along those lines), popped it in and the monitor worked again.
It had a little sticker with chinese printing and some pen scribbles on said EEPROM (some sort of warranty thing?) which made me wonder if that's the problem and they just reflashed the original chip so it'll fail again at some point in the future.

Read it out with my CH341A programmer, flashed the read-out .bin onto a new chip and put that on the original board and hey presto... works again.

Sadly this was 5+ years ago and I have no clue where the files went since then, otherwise I would've uploaded the FW dump here :/

edit: and once again I can't edit my old posts to fix all the dead links and images, even though I still have all the files in my backups