Samsung Syncmaster 245BW

[Nessdufrat]

Re: Samsung Syncmaster 245BW

Okay, guys, I'm finally back. I took forever, in the meantime I moved to another country, so lots of things to do. I got the multimeter, the screen is disassembled, I also disassembled the power board to recheck it in case I missed a bulging capacitor, I took some new pictures just in case and then remembered I already took all the pictures and attached them last year.
Now I'm hesitating : should I reassemble everything except for the back panel, prop it on some books and wait for it to go black again, or is there something I could check right now, since it's already taken apart?
Please bear in mind that I'm really a newbie at this kind of things. I can solder and unsolder resistors, I can check them with a multimeter, but I'm really unsure on how to do anything else (like check the power board while connected to the power supply and while switched on. Where do I put the multimeter red and black cables?).
Thanks!

[Nessdufrat]

Re: Samsung Syncmaster 245BW

Hi!
Sorry to dig up the thread, but my screen is open on a cushion next to me and I'm still hesitating on what to do with it. Is there something I can do to test the power board without reassembling it? Would it be possible (and not too dangerous) to plug it in while it's not connected to the screen? It might be way easier to test the circuits that way.

[Behemot]

Re: Samsung Syncmaster 245BW

Sure you can measure voltages. Just be sure to have on something non-conductive and be cautious, besides line voltage there will be about 650 V high-frequency AC from the inverter output.

[Nessdufrat]

Re: Samsung Syncmaster 245BW

Oh Gosh, now I'm super frightened... What is the piece I absolutely shouldn't touch? If I put it on a cushion, is it ok or should I put it on something else, like a wooden table? Sorry for all the stupid questions, but I'm really new at this

[Nessdufrat]

Re: Samsung Syncmaster 245BW

So, I finally put the screen back together without trying anything because let's face it, I have no idea what I'm doing. Now the blue button is solid, and I can't get any image. I tested it for a few hours, I guess I messed up something when I tried to test the components and by handling it.
Do I take the risk and buy a new power board, or do I just give up? What do you thing? It's around $65 where I live, should I do it? Solid blue button means the problem is with the power board, right?
Thanks for all advice...

[euromatlox]

Re: Samsung Syncmaster 245BW

If you decide to buy a new power board, be sure to buy BN44-00173A. It is compatible with BN44-00195A, and typically much easier to repair.

[Nessdufrat]

Re: Samsung Syncmaster 245BW

Hi!
Just wanted to give you some news. After much thinking, I bought the BN44-00173A power board. I loved this screen too much to throw it away without trying it first.
The board arrived today, I changed it, tested the screen, and it was bright white. At least there was some improvement. Clearly I had a faulty connection somewhere, and it was the flat multicolor little plug (I had no idea what it was for but it was so weird I figured it has something to do with the image signal). After unplugging it and plugging it again, tadam! My screen was alive
I tested it, the image is perfect, so it was indeed a faulty power board.
Too bad I didn't know how to use the multimeter correctly, it was probably one little transistor that wasn't working anymore, and it would have probably cost $10 to change it, but meh. I got the power board with a discount, and at least now it's working.

I'm offering just in case, but would somebody be interested in the old BN44-0195A board? I'll gladly ship it to anyone who is brave enough to use the multimeter Shipping costs might not be worth it though, unless you're in Europe.

Thanks to everybody who helped me, it took one year, but finally the screen is back

[Behemot]

Re: Samsung Syncmaster 245BW

00195 are PoS, nobody will want it. Got two, cannot find the problem. They are notorious for that.

You better replace the caps and scrap the glue out of the resistors right away before it goes bad again.

[Nessdufrat]

Re: Samsung Syncmaster 245BW

Okay, it will go in the trash tomorrow then ^^

[re-atari]

Re: Samsung Syncmaster 245BW

Last weekend I managed to save yet another 245B from the landfill. Bought a defective 245B from a Craigslist type classified ads website, failure described as 'does not give a display, power light is solid blue'. Turns out it has a 173A PSU (thankfully not a 195A!) with the well known 68R resistor (RB805) failure. Manfacturing date is november 2007.

On every 173A PSU these 3 resistors are drenched in brown glue. This gunk chars up and gets conductive and corrosive in the process. When removing it you will find the resistors' connecting wires are pitted with green corrosion. In my experience on a failing 173A PSU resistor RB805 shows open (infinite resistance), and RB806 and RB807 usually are OK. I replace them all three just for good measure, but with 3W types.

As resistors RB801 (100k, below the transformer in the middle of the board) and RP820 (47R, near the heatsink on the bottom left) are usually also covered in this brown gunk, they are just as corroded. I replace them as well.

I haven't had to replace the caps on any 245B yet. After replacing the above mentioned resistors the monitor immediately fired up without any problem. I have tested it out every evening since, it's rocksolid, no trouble at all.

Even though it's almost 10 years old, this still is a really nice monitor. 24" 1920x1200 16:10 monitors are getting scarce, standard for 24" ones these days is 1920x1080 16:9.

This will be a very good Christmas present for my parents.

re-atari