Samsung SyncMaster 245B Dead

[euromatlox]

Re: Samsung SyncMaster 245B Dead

I recommend replacing all these four capacitor before causing problems:

http://s807.beta.photobucket.com/use...02838.jpg.html

Helpful youtube video: http://www.youtube.com/watch?v=PCn_aG36Jt0

If you have problems with backlight, then the other two big electrolytes 1000uF/35v can also be changed (I have not have bl problems so they are still unchanged).

There is also a low quality 10uH smd power coil on video board, which might generate some annoying noise when moving mouse cursor etc. The video board is located under a metal plate, see picture

http://s807.beta.photobucket.com/use...00802.jpg.html

It does not have to be exactly 10uH, something near it will do. I have replaced this coil with 8.2uH coil. Physical size/height of the coil can and is recommended to be slightly bigger than 'original' but not much.

[Dyingsoul]

Re: Samsung SyncMaster 245B Dead

Hi there!
I also got a bad Syncmaster 245B.
It had the most common problem: the 3 resistor. I've changed them and now it is working perfectly, but i have a little problem with it: it is buzzing like a bee.

I have recorded its sound with my phone, its quite good quality and you can hear the buzzing actually (sometimes i hit the case with my phone accidently thats why you can hear knock-knock a few times).
You can check it CLICK HERE.

Its not that loud it would disturb me, but if i lean at the back of the monitor, its quite loud and makes me nervous. The power supply board has many clues of burn damage, but the amazing thing is that it is still working... I can see burned solder joints around the two fets and some other components, nearly on the entire board. But its still working!

Now im explaining an another serious damage, I ask for your forgiveness because of my lack of english/engineering skills:

http://s807.photobucket.com/user/bud...tml?sort=3&o=6

This is not my picture, but if you look at it, you can see a big white component labelled 2J 684J SIC 460S. There is a black component above that, nearly the same width but it is thicker, that is some kind of gate (i dont remember the exact name, thats why im explaining like this), it has 4 toe. I am talking about this black gate component, so the visual problem is the following:
If i flip the board and watch the backpanel, I can clearly see that the solder joints are loosed, it has solder on it but looks like the joint has been tore off from the PCB, lifted about 1mm high from there, but it is still connecting to the circuit. Looks really horrifying, too bad i did not take any picture of that before the assembly. If you find this important and my description is not enough then i will take apart again and take more pics.

Here are some of the pictures that i took from my board.
http://imgur.com/a/qIQ9R#9

If you can tell me what can cause such a buzzing voice, i would change some of the components, but if you say that its safe to use it until i get an image on this then ill get over it.

PS: Now im using this monitor for half an hour and it its back cover is hot like hell. (Not burning my hand, but much hotter than any other LCD monitor ive ever met.)

[selldoor]

Re: Samsung SyncMaster 245B Dead

I am not sure what you are asking - can you ask short one line questions.

The black component with a slant on top behind the white one is the Bridge rectifier
It converts the high voltage AC (230v)to even higher voltage DC (320v) You should not be using it untill it is firmly soldered.

Can you post a close up picture of back of the board where it is.
(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.

[Dyingsoul]

Re: Samsung SyncMaster 245B Dead

Okay, my simple questions are: Why is it giving out buzzing noise? Which component should I double-check in order to get rid of the buzzing? Might it be harmful?

[selldoor]

Re: Samsung SyncMaster 245B Dead

You are in the best position to tell what is buzzing?
From what you say it is probably the loose bridge rectifier.
If you keep using it it will self destruct. It could probably be fixed by gluing it to the board and to the white box
Is this it in the picture.

[Dyingsoul]

Re: Samsung SyncMaster 245B Dead

Yes, i was in the best position to tell what is buzzing. Maybe i could remove the back plastic cover and record the sound again, but that would be dangerous in my opinion.

Yes, thats it on the picture, as you can see, those are the loosed points. The white thing around the points are the lower layer of the PCB, as you can see it was ripped up.

Another question: Do you think it was made by somebody who was a complete idiot or it is self damage? Might have been opened before i got the display...

Edit: Tomorrow i will take some new pictures of the case. To be honest I am a bit afraid to touch the rectifier: afraid of breaking the circuit. Any advice on handling the situation would be appreaciated.

[selldoor]

Re: Samsung SyncMaster 245B Dead

Cant really tell how much damage there is to the board from the picture.

We need to bear in mind that it could need removing in the future so it would be best to use non conductive mastic between the bridge and the white box and more around the base. When it feels a bit firmer remove the old solder and resolder with fresh leaded solder.
To give it more support you could flow the solder along the trace to the next joint as in attached.

This is only one suggestion - perhaps wait and see if there are more (better) ideas

[Dyingsoul]

Re: Samsung SyncMaster 245B Dead

I've uploaded some new images of the rectifier's bottom. Also did some from the 2 fets, there is a sign of excessive heat. Glue burned down there around the resistor.

There is a component printed DZM803 on the board, it looks like strage to me, dont know why... like it is a bit burned or i dont know if it is the normal color.
http://imgur.com/a/qIQ9R#7

[selldoor]

Re: Samsung SyncMaster 245B Dead

I have asked you to upload the pictures as an attachement if you do not I will not look at them DZM803 is a zener diode orange/red and black stripes are normal.

It is the Glue that causes the burning - you should remove as much as possible.

I understood you to say that the monitor was working OK but making a noise and running hot. is that correct?

[Dyingsoul]

Re: Samsung SyncMaster 245B Dead

Sorry for not uploading here. Now i did it, you can take a look at them.

[Dyingsoul]

Re: Samsung SyncMaster 245B Dead

I understood you to say that the monitor was working OK but making a noise and running hot. is that correct?

When i got the monitor, it has no picture. The led was blinking blue. I had to change the 3 resistor (most common problem on this model), in order to get it working.

[selldoor]

Re: Samsung SyncMaster 245B Dead

Yes but is it working NOW?