Samsung Syncmaster 225BW

[S0und]

Re: Samsung Syncmaster 225BW

I dont know what is available in Hungary - try to stick to leading brands - panasonic

Luckily, Farnell ships to Hungary.

http://www.digikey.com/product-detai...613747?cur=USD
http://www.digikey.com/product-detai...613752?cur=USD
http://www.digikey.com/product-detai...266330?cur=USD

Someone mentioned in the topic that FM series is a good choice. But caps lifetime variates from :

330uF - 4000 Hrs @ 105°C
820uF - 5000 Hrs @ 105°C
47uF - 1000 Hrs @ 105°C

so what is the priority, go with a good series, or aim for higher hour/°C

[selldoor]

Re: Samsung Syncmaster 225BW

I have not been aware of many members looking at lifetime of caps.
if you want a longer life you could go for this
http://www.digikey.com/product-detai...5CT-ND/3072165

By going up a voltage step you can get an FR series cap which is longer life.

[kaane]

Re: Samsung Syncmaster 225BW

Yes. With power off and your meter set to resistance, place your probes across F301. You should read 1 ohm or less. This fuse supplies power to the backlight circuit.

I'm quoting this as a placeholder for the fuse related posts I read in the past hours

Replacing the fuse made my 225BW work again.
Symptoms were: blue LED permanently on and reacts on power button though absolutely no acticity on the screen (as flickering, going on and off etc.).

Before the fuse I changed 5 of the caps (I overlooked the 47nF Cap before I went to the store), what I don't think was unneccessary in the long run as one of them didn't look to well.

Thanks everyone on the thread.

[syncmasterprobs]

Re: Samsung Syncmaster 225BW

Hey, guy's new here, but my syncmaster 245bw (just posting here because it is a similar monitor and and active thread ) was having discolorations in the screen from time to time. So I took it apart mainly looking at the power board (haven't looked at the logic board) and have spotted at least one cap that's bulged (also has black stuff on top).

the bad cap says 10v 2200uf 105 deg C and samsung WL

If I just buy a simailar cap and replace it will it likely fix my prob?

[syncmasterprobs]

Re: Samsung Syncmaster 225BW

Sorry for double post but I was unable to edit me first post (I can move to the 245bw thread if you guys want sorry).

here are pics, hopefully they are good enough quality.

I'm not having major issues with this monitor so I am hoping it will be a simple fix (my first).

[rodneygibbons]

Re: Samsung Syncmaster 225BW

Sorry to go a little off topic, but I am a new member and thought the posters at this thread may be able to help me.

I am looing for a Samsung 225BW LCD Monitor Driver Controller Board BN41-00772A. I have found many suppliers of BN41-00772B and BN41-00772C, but none for the A version. Does anyone know if the B or C versions will work.

One fo the capacitors broke free, and I don't know how to solder boards.

[edster]

Re: Samsung Syncmaster 226BW

Hello to All,

I have the black screen syndrome. I've changed all the caps..even those that were not domed. Still have black screen..and power light flashes. Took apart and rechecked solder joints..they seem ok. I put my voltage meter on the 13.5 volt pins (where the ribbon attaches) and it flashes from 14 volts to .1 volts continuously on all 3 +13.5 volt pins. This flashing seems to match the flashing blue led on my monitor on button.

Off hand..can anyone suggest which component would cause this as I would think the power should be a steady 13.5 volts on each of the + pins.

The pins going to the screen are all showing 3.9 volts or slightly higher.

Thanks,

Ed

[selldoor]

Re: Samsung Syncmaster 225BW

This thread seems to cover all possible errors and tests you can do.
If as it suggests you have replaced ALL the caps with good make low esr caps
then test the inverter transformer/s and the bulbs.
See the Guide 2 seconds to black for all the tests - sticky at the beginning of this forum
Post the results of the tests and good clear pictures of your boards

[kotekzot]

Re: Samsung Syncmaster 225BW

The fix for me was:
1. Press "down arrow" key.
2. Hold down the "enter" key for 10 seconds.
3. Turn off and back on. The redness disappears.

this solution has fixed the screen being red almost every time, though occasionally the monitor will simply fail to show anything, in which case i just had to wait a few days for it to go back to normal (the fact that it's my secondary monitor allows me this luxury).

[spuzzum]

Re: Samsung Syncmaster 225BW

Well, I originally had the same issue as ppmz.. my Syncmaster 205BW went completely red last week, but not seeing this thread yet, I found another 205BW on craigslist for $35. But when I went to pick it up.. it went red as he's showing it to me. He gave it to me for parts. I then found this thread, and decided to use his monitor as the tester. Opened it up, and sure enough.. his power board had 3 buldging caps, with 1 of them leaking. I ordered enough caps for both monitors from Digi-Key:

1000uF 25V, 105°C, ESR: 18mOhm, Ripple Current: 2A ($1.02 each)
http://www.digikey.com/product-detai...2379-ND/613740

470uF 25V, 105°C, ESR: 19 mOhm, Ripple Current: 1.6A ($0.80 each)
http://www.digikey.com/product-detai...2415-ND/613776


2 days later, I did the surgery on his board... full colour screen, for all of 5 minutes. The buttons locked up again, as well as the corrupted eeprom. I tried the button combo ppmz mentions:

1. Press "down arrow" key.
2. Hold down the "enter" key for 10 seconds.
3. Turn off and back on. The redness disappears.

But that didn't help. I decided to pull it apart again, but couldn't figure it out. I then tried his power board in my monitor.. everything's dark red. I pushed the buttons to see if it locked up again, but something I pushed made everything better.. I think it was the "up" button. Maybe it was just a matter of sending a new signal with a fresh voltage. Don't know.

5 days later, I decide to work on his monitor again. I put it together, including my power board.. which I recapped anyways, and for whatever reason.. it boots to a full colour screen. Happier than a pig in slop, I had a dual monitor system running.. again, for 2 days. I woke up today to my monitor a dark red. I tried the button combo.. nothing. I tried the up and down button together.. caused the power button to flicker, so I figured it reset something. I powered the monitor off and back on using the flip switch at the bottom of the unit, and now.. instead of a dark red screen, I have a darkened full colour screen, without a menu button, and the down key pops up a corrupted menu at the bottom left of the screen. Blah.

Both times the monitors went bad, my pc was running a video project overnight.. but the monitors were turned off. So I don't see how that would affect them. And my video card's fairly new as well.. GTX-660.

Doing some more googling, I came across a video on youtube where the guy's front panel wouldn't even power the power button. His fix came down to the caps on the logic board itself.

http://www.youtube.com/watch?v=djn3tFunhCQ


So now I'm wondering if that's been the cause of my monitor the entire time. The 2nd monitor I picked up is still running fine. It's either that, or I still need to recap the big-assed power cap and little tiny cap still on the power board. They looked ok.. but as I've read, looks can be deceiving.

I guess I'll pull the logic board and test the readings on the caps. Every time I try testing the ohms on any caps though, my meter doesn't sit still.. numbers keep moving.. and that's with a new cap, never been in a circuit. Maybe I need a new meter as well. :P

[spuzzum]

Re: Samsung Syncmaster 225BW

Well, according to that video, those 100uF 16v surface mount caps should be between 0.6uF - 0.9uF.. at the highest. My readings were 0.50, 0.52, then 5.77, 5.81, and even 14.37 Ohms. I think I found the problem. They're all the same caps, so they should all have the same ESR. :P

I'm about to pull some 100uF 16v caps from an old motherboard.. I haven't checked the Ohms on them yet though. Worst case is another order from Digi-Key... I need some more stuff for another project anyways.


Fingers crossed....

[spuzzum]

Re: Samsung Syncmaster 225BW

Nope.. making a Digi-Key order. Caps from the motherboard were 18+ Ohms.

[spuzzum]

Re: Samsung Syncmaster 225BW

Well.. caps came, but when removing the old caps.. 1 of the pads came up off the board. I tinned and soldered to the trace, but no go... blank screen. I must have broken the connection to the other side of the pad. Oh well.. I guess I'm looking for a new driver board off ebay.

[spuzzum]

Re: Samsung Syncmaster 225BW

Well, I was able to find a throughole connected to the trace of the pad I lost, which I was able to tin and connect a wire from the leg of the cap to. It doesn't look the prettiest, but I now have power again. I then lifted pin8 of the IC200 A81SC... full colour desktop again. My local shop carries the AT24C08N, so I'm picking up a rework station at the end of the month and a couple of chips.. 1 for each monitor.

[selldoor]

Re: Samsung Syncmaster 225BW

Hi spuzzum
Just to congratulate you on your efforts with this and to thank you for
writing it all up, should be of great help to others

[thraxarious]

Re: Samsung Syncmaster 225BW

Hello again, got one of these acting up again. I am not certain if it is the picofuse or not, it sounds like it.

Blue power comes on, no screen. If you turn it off right away after connecting power, it will let you toggle power, but any more than a few seconds and the power buttons forget how to work. No other response from other buttons.

I replaced the last of the caps (was lazy last time), so they're all now the Panasonic ones, except for the big C cell sized can.

I've been having trouble getting a good reading on the Picofuse (F301), I think I'm getting 1ohm, but It can sometimes seem to fluctuate. Depends on where I am reading it (still soldered in, but that shouldn't matter, path of least resistance and all that). It might be my crap multimeter, dunno.

[selldoor]

Re: Samsung Syncmaster 225BW

Test the voltage on each side of the fuse with respect to ground.
Pictures of your boards might help us spot something

[thraxarious]

Re: Samsung Syncmaster 225BW

Picked up a couple images.

I'm having a bit of trouble measuring the voltages. Against the ground AC pin I get nothing. I'm trying to measure voltage at around 200v as those fuses are 125v (the other being 250v).

Can't rule out my multimeter or how I'm measuring. I have two and they both don't really register anything there.

[selldoor]

Re: Samsung Syncmaster 225BW

You are frightening me - you need to do a lot more reading. The voltage value on the fuse
often bears little resemblance to the voltage it might carry though it is the maximum it might carry. In a thread this length almost everything you need to know has been mentioned before. The voltage at this fuse should be around 13vdc.

The board is divided into 2 sections HOT and COLD divided by a thick black line.
The ground for the hot side is separate from the ground on the cold side.

So the secondary side ground is usually at the ground screw holes.
One is in the centre of this board almost next to the fuse. Usually you can touch this from eaither side of the board but I cant tell from the picture if that is possible.
If you are testing in the frame then it is just on the screw that goes through the hole.

[ylsf]

Re: Samsung Syncmaster 225BW

Hello all,

Just a quick note to say thanks for this forum. I am in the middle of trying to repair a Samsung 225BW and I was about to give up but I figured I would post here for help first and hopefully be able to resolve my issue. I just managed to fix my parents Samsung fax machine by replacing a cap but I didn't have success (yet) with my monitor. I originally followed a youtube video which didn't obviously go into the detail that is on this thread.

My symptom is blue light is on. I can see the screen image if I shine a flashlight on it but otherwise no backlight is coming on (i.e. dark monitor).

I am attaching pics of the back and front of my board (after I replaced the caps... and after my BAD solder job). This is the first time I have soldered since doing a few things in high school many years ago. You can see on the back of the board I managed to get some solder on some of the PCB where it shouldn't be. I tried to clean up the solder but I think the pump that I bought is defective (I realized it was already used when I got it home from the store and the package was opened previously). If it is possible that which is causing an issue I will probably buy some desoldering wick but I didn't want to make it worse by fooling around with it.

I don't have a high res picture of the board prior to me making the changes but I have since changed out 6 capacitors.

These were the capacitors I had on my board:

The two by themselves in the middle of the board -

680 uf 25v (two) replaced with Nichicon 680 uf 35v H0912 HE(M). I did this on the basis of a recommendation from the lady in the shop as they didn't have any 25v capacitors of that uf so she said I could go higher. I googled after and didn't come across a conclusive answer if that would work but most people said depending on the application it would be okay.

Replaced the 47uf 50v with a Capxon 47uf 50V

Now, the three that are all together were different on my board than what I have seen other people post. The one closest to the edge of the board was an 820uf v25 and then the other two were 1000uf 25v. I replaced them with the same uf and voltage rating capacitors.

the 820uf was a H1305 HV(M) from Nichicon and the 1000 uf was a H1305 PA(M) also from Nichicon.

I am attaching a pic as well of the original capacitors that were together (the 3 in a row ones).


In retrospect maybe I should have ordered the capacitors online. I didn't read about the "low esr" thing until after I replaced them and not


I also replaced the F301 fuse with a 3a 125v fuse.

My time line was I first replaced the two 680uf 25v with new capacitors because they were bulging. I am attaching a pic of those two capacitors as well. The other capacitors looked ok visually before I replaced them.

So after that long post my question is, will using a 35v capacitor vs. a 25v one cause an issue? Is it worthwhile for me to order in the 25v ones?
Any other suggestions?