Samsung Syncmaster 225BW

[be_rad]

Re: Samsung Syncmaster 225BW

Thank you so much for this post! A few new caps and my monitor is working as good as new!



Thanks!
Brad

[jmer1975]

Re: Samsung Syncmaster 225BW

i have a problem with my samsung syncmaster 225bw. it don't display anything but it has power and it's not blinking. i changed all the caps, ive replaced the two 820uf 25v with 1000uf 25v cause i can't find that caps in my area. and the problem is still there.

what do you think is the other problem of my monitor.

by the way i disconnect the 4 lamp wire and i can't remember where to put it back if it is PINK, BLUE, BLUE, PINK or is it BLUE, PINK, BLUE, PINK connection.

pls help.

[Bobdee]

Re: Samsung Syncmaster 225BW

Hello
Have you checked Inverter fuse (green)
Probable Inverter or CCFL problem
As for CCFL connections they go PINK BLUE PINK BLUE
Nah just kidding
Plug them back in as they come, no particular order
Just right side up (dot to top)
IF that dont help
Were the replacement caps low ESR???
Are the backlights coming on at any time???
Post a picture of both sides of board (if possible) as this wil help members to help you
Bob

[Bobdee]

Re: Samsung Syncmaster 225BW

Also shine a bright torch into screen, to see if you can see a faint image of your desktop when PC and Monitor on

[jmer1975]

Re: Samsung Syncmaster 225BW

Sir is the inverter fuse is the one that has a value of 125v 3a? i test its continuity, at first it didn't beep, when i invert it it beeps then stops, i invert it again and its the same. do you think it's ok?

but before i test the fuse i try to put a bright torch at the screen as you suggested, and yes there is an image on the screen.

do you think its the CCFL or just the backlight? by the way the backlight doesn't light up, i think.

how do i test and remove the backlight incase it is the one to replace?

[PlainBill]

Re: Samsung Syncmaster 225BW

Sir is the inverter fuse is the one that has a value of 125v 3a? i test its continuity, at first it didn't beep, when i invert it it beeps then stops, i invert it again and its the same. do you think it's ok?

but before i test the fuse i try to put a bright torch at the screen as you suggested, and yes there is an image on the screen.

do you think its the CCFL or just the backlight? by the way the backlight doesn't light up, i think.

how do i test and remove the backlight incase it is the one to replace?

The inverter fuse is the one circled in green in the attached picture. The results you describe indicates the fuse is open. (The brief beep occurs as the caps charge). Check the drivers; if one of them is shorted it would cause the fuse to fail. The drivers are circled in blue. Check pin 1 to pin 3 (blue lines) on each of the drivers. If they show open replace the fuse with an equivalent (125V 3A) fuse.

PlainBill

[jmer1975]

Re: Samsung Syncmaster 225BW

good morning! (Philippine time)

can i use a 5A pico fuse replacement for 3A because its hard to look for it especially in my area.

an electronic shop owner told me that it can be replaced by a resistor but i don't know if that is true. if it is, what would be it's value?

[Bobdee]

Re: Samsung Syncmaster 225BW

good morning! (Philippine time)

can i use a 5A pico fuse replacement for 3A because its hard to look for it especially in my area.

an electronic shop owner told me that it can be replaced by a resistor but i don't know if that is true. if it is, what would be it's value?

Do not replace with 5 amp, that would be a fire hazard and if not fire a lot of damage to monitor if you have furure problems with monitor
You could try rigging up another sort of fuse in fuse holder such as small glass 3amp fast fuse and wire it in untill you can get a new one

[jmer1975]

Re: Samsung Syncmaster 225BW

it works! thank you very much Master Bob and Master Plainbill. you saved me from spending a lot of money by bringing this to a service center. and i will pass this knowledge i've learned to my friends who has the same problem as mine.

I am very thankful for you guys...GOD BLESS!!! MERRY CHRISTMAS!!!

-- "Master" is what we call to a person who shares knowledge to others

[Luscious]

Re: Samsung Syncmaster 225BW

My 225BW will come on for a second, and then go black, except that there is still a very faint image on the screen. I've taken apart the monitor, and inspected the capacitors, and it doesn't look like anything is wrong with them, although you guys have said that that doesn't necessarily mean anything. So I've attached two pics of the board (front and back) and hopefully I can get some advice on what the problem is!

[Bobdee]

Re: Samsung Syncmaster 225BW

Sounds like inverter or CCFLs or possible caps
As you say it comes on for a second or two that implies the inverter fuse is ok so the mosfets should be ok
Worth checking the CCFLs before recapping
Also check for any bad solder joints on the back of board

[PlainBill]

Re: Samsung Syncmaster 225BW

My 225BW will come on for a second, and then go black, except that there is still a very faint image on the screen. I've taken apart the monitor, and inspected the capacitors, and it doesn't look like anything is wrong with them, although you guys have said that that doesn't necessarily mean anything. So I've attached two pics of the board (front and back) and hopefully I can get some advice on what the problem is!

One of these days I'm going to write this up properly and bookmark it. Here's the short version of backlight system design.

The core of the backlight system is the inverter controller. It is usually a PWM controller with some safety features. The main controller on the logic card sends a signal to the inverter controller. The inverter controller begins driving the CCFLs at full brightness. Several seconds later it begins monitoring several parameters. These include one or more of voltage to the CCFLs, Current through the CCFLs, and drive current of the inverter transformers. A parameter can trigger a fault condition if it is too high, too low, or both.

The voltage driving the CCFLs is too high a voltage to safely measure without a special high voltage probe, but there are other ways. On the attached picture I have circled four points in red, four points in blue. For convenience we will call them the left pair and the right pair.

With power off, measure the resistance between the left pair of red points. Now measure the resistance between the right pair of red points. Report them. Now measure the resistance between the left pair of blue points; and between the right pair of blue points.

If the resistance between the pairs of blue points is greater than 50 ohms, proceed with the following test. Hook the board back up to the CCFLs and the logic card. Fasten it in place with at least the two screws at the side with the CCFL connectors. Note that each CCFL connector has 4 pins. For convenience we will number them from left to right as 1, 2, 3, 4, 5, 6, 7, and 8. Not also that the odd number pins are the pins that were circled in blue. Also, the wires that connect to them may be smaller in diameter. If they are the larger diameter wires STOP!! Do not continue!!!

Now for the test: While the backlights are on, measure the voltage between each odd numbered pin and ground. Repeat the test several times for each pin. Report these voltages.

A cleared picture of the back of the board would also be helpful.

PlainBill

[Luscious]

Re: Samsung Syncmaster 225BW

I don't have a resistance meter, I'll have to go to Radio Shack and pick one up.
But Here are some (hopefully) clearer pictures of the board.
The first two are the left and right halves.

The last four are the top left, top right, bottom left, bottom right in order.

"Not also that the odd number pins are the pins that were circled in blue. Also, the wires that connect to them may be smaller in diameter. If they are the larger diameter wires STOP!! Do not continue!!!"

Larger diameter than what? The red ones?

Thanks!

[skeppers]

Re: Samsung Syncmaster 225BW

Hello all,

My display recently went all black, solid power light. I replace the capxon capacitors and managed to get the picture back up. However, now whenever any button is pressed on the front panel (besides Power and Auto) the screen goes black and no buttons will respond (It won't turn off using power button). The other issue is the fact that the screen only displays in shades of blue. Anyone experienced anything like this?

[PlainBill]

Re: Samsung Syncmaster 225BW

Hello all,

My display recently went all black, solid power light. I replace the capxon capacitors and managed to get the picture back up. However, now whenever any button is pressed on the front panel (besides Power and Auto) the screen goes black and no buttons will respond (It won't turn off using power button). The other issue is the fact that the screen only displays in shades of blue. Anyone experienced anything like this?

Never saw something like that before. What did you use for replacement caps?

PlainBill

[skeppers]

Re: Samsung Syncmaster 225BW

I used some caps a local supplier had (Illinois brand), same ratings and size on them. Pulled it apart, verified all the connections were fully seated, tried both VGA and DVI cables with same results.

This is what the screen looks like at the moment.

http://i49.tinypic.com/2echwes.jpg
http://i49.tinypic.com/vy3wqa.jpg

[PlainBill]

Re: Samsung Syncmaster 225BW

I used some caps a local supplier had (Illinois brand), same ratings and size on them. Pulled it apart, verified all the connections were fully seated, tried both VGA and DVI cables with same results.

This is what the screen looks like at the moment.

http://i49.tinypic.com/2echwes.jpg
http://i49.tinypic.com/vy3wqa.jpg

And what is the ESR rating of the replacement caps?

PlainBill

[skeppers]

Re: Samsung Syncmaster 225BW

I am unsure, how do I determine their ESR rating?

[SLBEngineer]

Re: Samsung Syncmaster 225BW

My Son has a Samsung Syncmaster 226BW. When it comes on it shows the analog box then goes black. After reading the post I took it apart and the caps looked good, but I replaced C110, C111 and C112. I then read further and found I can shine a flashlight into the screen and see the faint desktop. Can other bad caps cause this problem? I have checked the fuse and it appears to be good. I am looking at this section of the post

" If the resistance between the pairs of blue points is greater than 50 ohms, proceed with the following test. Hook the board back up to the CCFLs and the logic card. Fasten it in place with at least the two screws at the side with the CCFL connectors. Note that each CCFL connector has 4 pins. For convenience we will number them from left to right as 1, 2, 3, 4, 5, 6, 7, and 8. Not also that the odd number pins are the pins that were circled in blue. Also, the wires that connect to them may be smaller in diameter. If they are the larger diameter wires STOP!! Do not continue!!!"

I have checked the resistance and found red connectors read 1085 and 1094 ohms, and the blue connectors read 719 and 720 ohms.

What else could cause my problem?

[J_Fellenbaum]

Re: Samsung Syncmaster 225BW

I would just like the thank everyone one in this thread, the forum and the website in general for all of the information! I broke out my soldering iron for the first time since a quicky class some 10 years ago.

I've got my Monitor back! I had the blinking Blue light, changed the 5 caps listed and back in business! I will keep this website bookmarked for any future electronic trouble as there is tons of info on here! Glad Google directed me here!

Thanks again guys!