Troubleshooting Syncmaster BW205

[frevab]

Due to limited funds and a techinical inquisitiveness I am trying to get the display of my daughter working again. First the creen for many months a had a mind of it's own: most days it was working fine, some days redisch screen, some days dull screen. Just a matter of knowing how to start her up!
Finally it died. Changed the CCFL tubes but black screen.

How do I troubleshoot it further to find out where the problem is.
When I connect the power and push the power switch the blue LED come on. I hear a light high pitch noice when the power is on.

Does the blue led mean my power supply board IP-43130A is ok?
I have taken the power supply board and the PCB out of the screen chassis to read all the part numbers. Can I just connect the CCFL tubes to the power board connectors and put the power plug in to test the CCFL lights?

The operation button on the front (menu upto power) are connect to the PCB. As the power LED is working does that when the PCB is ok?

Where is the inverter located? Can this be broken down?

Can anyone help me to find out why it is not working?

Thanks!

[lcdman]

Re: Troubleshooting Syncmaster BW205

Hello frevab,

First off welcome to this great forum. Are you sure you have the right model number? Perhaps its a 205bw instead? If so i'm including a service manual. Your boards might be a different revision level or layout. Also search this forum for any additional information you might require on this model. The inverter board should be the larger of the two circuit boards, aside from the power/function board. The inverter circuit board is the one the bulbs are attached to.

Good Luck With Your Repair,
lcdman

[budm]

Re: Troubleshooting Syncmaster BW205

Is this the same board as yours?http://s807.photobucket.com/user/bud...?sort=3&page=1

[selldoor]

Re: Troubleshooting Syncmaster BW205

There are lots of threads regarding this board you need to search 205BW
not BW205.
Pictures always help us to help you

Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed

https://www.badcaps.net/forum/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246

[frevab]

Re: Troubleshooting Syncmaste 205BW

Herewith some images of the boards and pcb.

[frevab]

Re: Troubleshooting Syncmaster BW205

Thanks lcdman. I found that service manual one already.

[lcdman]

Re: Troubleshooting Syncmaster BW205

Hello Again frevab,

I think its a cap issue first off. Possibly even those two 8 pin ICs have gone bad in front of the lone two caps on that board. Check the dimensions for the caps on your board. Diameter in mm X Height in mm. Height being the most important issue. If too tall you won't get the monitor to close back up. Then go to Digi-key,Mouser,Farnell but not Ebay for Panasonic FC,FM,FR series aluminium electrolytic capacitors. There are alot of known fakes on Ebay! There should be some on either of those three sites that come very close in size to what you have.

Take Care,
lcdman

[frevab]

Re: Troubleshooting Syncmaster BW205

Result bad caps the type of malfunction of the screen like I described in my Original post? It started off with a red(ish) image once in a while. Or not so bright colour as normal. Often when I switched on the PC the screen went inn standby after a few seconds. When I left it like that and turned it back on after 10-15mins it was often perfect no problem at all but sometime I had to repeat that or accept a dull screen. The next day it could be fine though. If it was not working it made some more noise than normal.

[frevab]

Re: Troubleshooting Syncmaster BW205

Possibly even those two 8 pin ICs have gone bad in front of the lone two caps on that board.

I am not technical enough to identify the ICs. Are these the one on the attached image close up U301 and U302? Are they easy to get? What does IC stand for?

These are the caps I have found on the board:
5x 20mm Ø10mm 820uF 25v C317-318-111-112-114 (brown cap)
1x 12mm Ø10mm 330uF 25v C113 (brown cap)
1x 10mm Ø5mm 2.2uF 50v C118 (brown cap)
1x 12mm Ø5mm 47u/50v C107 (black cap)

Following earlier posts I have already found
Al Electrolytic Cap 105C 25V 330uF (5261519 Panasonic EEUFM1E331 RoHS-status - Conform) and
Capacitor Al FR 820uF 25V 10x20 (7083743 Panasonic EEUFR1E821 RoHS-status - Conform)
on the webshop of RS Components

[lcdman]

Re: Troubleshooting Syncmaster BW205

Hello frevab,

Yes those two items in your picture are ICs. I'm sorry I didn't explain what IC stands for. It stands for integrated circuit. I don't know if they (IC)s are easy to get. Take the info from the top of the ICs and check Digi-key,Mouser,Farnel,etc to see if they carry them. Also you can search for the ICs on Ebay. I don't think these are as easy to make fakes of like capacitors. But then again I don't everything either. Try the capacitor replacing first, that might be all that is at fault. I took the time to search Digi-key to reference the size dimensions from your last post. You can get them from Digi-key or where ever you like or get the best rate for shipping on.

Take Care,
lcdman

820uf 25v : http://www.digikey.com/product-detai...423-ND/2433557
330uf 25v : http://www.digikey.com/product-detai...415-ND/2433549
2.2uf 50v : http://www.digikey.com/product-detai...0313-ND/266322
47uf 50v : http://www.digikey.com/product-detai...0321-ND/266330

[budm]

Re: Troubleshooting Syncmaster BW205

Those two devices are Dual MOSFETs for driving those two inverter transfromers. Try to get the numbers as printed on the top of the devices.
So far I see 6 bad caps with domed tops. You should replace those caps at least.

[frevab]

Re: Troubleshooting Syncmaster BW205

Hi guys. Has been a while.

I have been looking for the caps but had to buy them in 5's and 10's so while googleing I came across a new board. In the end it was not much more expensive and would save me a lot of hassle trying to soldier the caps as I have no experience in soldering.
Had to wait a while to receive the new board and it looks fine except for one item which is on the new board but not on the old board: on VA101 there is a TVR 10621. What is this for and what difference does it make being there compared to the old board that didn't have one?
I enclose an image with LEFT the new board and RIGHT the old (original) board. VA101 is on the left bottom corner.

I have connected to new board and connected the CCFL tube. With the old board I did not have any display but now it starts ok (perhaps less bright than before) but dies after a second or so. Why could this be? One of the tubes not ok? I got new tubes and resembled them into the screen as I was afraid to test them just like that outside of the screen bodywork. Can you just light them up connect to the board (careful of course because of the high voltage)?

[budm]

Re: Troubleshooting Syncmaster BW205

That VA101 is the Varistor (MOV) for surge protection, it is connected between line and Neutral, the board will work without it but then you will not have surge protection.
When you power up the board, do you have the main board connected to the running PC? Otherwise it will go into standby mode if it does not detect video signal from the computer.

[frevab]

Re: Troubleshooting Syncmaster BW205

That VA101 is the Varistor (MOV) for surge protection, it is connected between line and Neutral, the board will work without it but then you will not have surge protection.
When you power up the board, do you have the main board connected to the running PC? Otherwise it will go into standby mode if it does not detect video signal from the computer.

Thank you for your reply and info about the MOV.
In the meantime I have connected the old CCFL tubes (that I thought were worn out) to the new board outside of the bodywork and found out that the old one was working fine. One of the 2 tubes was broken when I replaced them but the other ones was working fine. I discovered that one of the new ones was not working properly and resulted in a red display colour. This is one part of the double tubes so I will probably put the old one back in. I got these new lamps as "CCFL Lamps Full Assemblies" so perhaps something was damaged during transport or assembly in the screen.

Yes I have connect the main board to a PC to avoid standby mode.

Will the CCFL stay on until I switch it off when I test it outside of the screen bodywork or should it go off after a long while (i.e. 10 secs) or can this also be a famous 2 second black?

while I am here and probably not the correct place to ask, but you have more experience in this kind of stuff than me: I am also repairing (or trying to repair) a Dell laptop screen. I have replaced the tube and small inverter board but screen was not working. when I had the laptop on for a while and came back in my room it was working fine. So I thought perhaps it just had to warm up but after a while it was off again. This was the original problem: the screen goes black and back to normal it's own and when it wants. When I put a lamp op the screen the display is working but no backlight. The inverter board and lamps are new. Inverter-board has a power light and this is green all the time. It there any thing that can cause this. 2 seconds black is going to black screen but not going back to live on it's own after a while, or is it?

[budm]

Re: Troubleshooting Syncmaster BW205

"Will the CCFL stay on until I switch it off when I test it outside of the screen bodywork" They should stay on as long as the PC keeps feeding the video signal to the Main/logic board or until you hit the power on/of switch. The error detection circuits will activate in the first 3 second if it detect the lamp is not connected, the lamp fired up but does not stay lit. Then there is another over current draw protection.
I made fixture for testing lamps:
http://s807.photobucket.com/user/bud...?sort=3&page=1

[frevab]

Re: Troubleshooting Syncmaster BW205

I have 4 2-pin connectors. Does it make any difference in which order they are connected to the board? Like on your tester photo: you have 2 connectors on the bottom and 2 connectors on the top of the board. Due to the position you can only connect the tubes from one side of the screen to one of the two connector positions (bottom or top) but does it make any difference if you switch i.e. the 2 lower ones from left to right?

The replacement laps I received have other wire colors but the 2-pin connector makes sure you can only stick them in one way.

I did not know you can just lite up the tubes outside the screen. I was afraid the light would be to bright or the lamps would not work but now I know you can so you can test the lamp just on their own connected to a board which has a live display feed from the PC.

[budm]

Re: Troubleshooting Syncmaster BW205

4 connectors (1 big wire, 1 smaller wire) for 4 individual lamps so it does not matter which receptacle you will use. Only the length of the wire will limit where you can plug in the lamps. They can use Pink, white, blue, black, or what ever color wire they want to use.
You can also make test lamp to find out if the inverter is bad or the lamp is bad.
https://www.badcaps.net/forum/showthread.php?t=19987

[Blocki]

Re: Troubleshooting Syncmaster BW205

I know the thread is a lill' old but I am curious about the "reddish" part and the C118 on frevab's new PSU board. It looks kinda weird. This could cause his new problems he is facing with the "new" board.

I have the same screen and also recapped the whole PSU board and the screen goes on again. But sometimes the screen is reddish (seldom) or the screen is pale/contrast overdriven.

Another symptom I have is trouble with the DVI for which I already created a thread: https://www.badcaps.net/forum/showthread.php?t=21922

My question to frevab would be if he was able to fix his screen entirely with the new PSU board (incl. the reddish problem and the dull issue).