2 x Samsungs 2493HM - Double the Trouble!

[mr_mooray]

Im new and probably screwed up, please be kind

I have 2 Samsung 2493HM monitors, I saw that both of the monitors had a bulging 10v 2200uf cap on the power board and replaced them with a Yageo 16v 2200uf cap. I read that the extra voltage is a good thing, but perhaps I should use a better panasonic cap?

Monitor 1 - Kinda works now but the color isnt right (too green) and I cant seem to use the menu (tried unlocking and resetting monitor but it doesnt work). Also it buzzes/hums a little. Could this be a cap related problem, should I try replacing other caps or the same cap with a better cap ?

Monitor 2 - When I removed the cap some of the green PCB came off. Now the monitor LED comes on but the monitor doesnt come on at all, I think I may have ruined the power board? %&!#

What do people think ? I have attached pictures for the power board which I removed some green off of.

[ipman]

Re: 2 x Samsungs 2493HM - Double the Trouble!

For monitor 1, did you use a low-esr cap?
For monitor 2, just clean the green protection a bit and solder nearby. Should be no problem, you are lucky with that big pad.

[mr_mooray]

Re: 2 x Samsungs 2493HM - Double the Trouble!

Monitor 1: I used a Yageo 105C 16v 2200uf capactior, sorry I cant say whether thats low-esr because I don't know what that is.

Monitor 2: How would you reccommend cleaning it, and can I just solder where there is some green near it ? I thought it would have to be near/on the fine black line ?

[mr_mooray]

Re: 2 x Samsungs 2493HM - Double the Trouble!

Monitor 1: It was working occasionally after "heating up" but then I saw the bad cap and replaced it and now the LED is constant but it doesnt turn on. This to me just suggests that either the cap I replaced it with isnt good, or I didnt attach it properly (the green pcb problem).

[PlainBill]

Re: 2 x Samsungs 2493HM - Double the Trouble!

Yageo does make some low ESR caps. There should be a two letter series identifier, usually near to the temperature rating. What is that code?

PlainBill

[mr_mooray]

Re: 2 x Samsungs 2493HM - Double the Trouble!

"SY 105C"
"08/10"
"C2"

I presume SY is the series identifier.

I am thinking of buying and replacing all the caps on the power board with panasonic ones, do you think this would fix the problem with the color etc. and the problem with the other monitor not turning on ? With regards to the green pcb that I kinda ruined any tips ?

[PlainBill]

Re: 2 x Samsungs 2493HM - Double the Trouble!

"SY 105C"
"08/10"
"C2"

I presume SY is the series identifier.

I am thinking of buying and replacing all the caps on the power board with panasonic ones, do you think this would fix the problem with the color etc. and the problem with the other monitor not turning on ? With regards to the green pcb that I kinda ruined any tips ?

The Yageo SY series caps are nothing to brag about, but they are one of their low ESR series. I really doubt they are the cause of your problems.

On the board you performed the exotic modifications, it's not that bad. It's one of the reasons we suggest practicing on a scrap board. If you have another capacitor, install it, but instead of trimming the leads, solder them to the traces past the destroyed area. A PC board is made my laminating a thin sheet of copper onto a fiberglass base. The excess copper is then etched away, and a coat of green solder resist is applied. Simply scrape the solder resist away, apply a small amount of solder to the bare copper, then solder the lead to that point. It won't meet mil spec, but these aren't mil spec monitors.

As far as the other problems, I suggest marking all boards with either an A or a B, depending on which monitor it belongs to. For convenience, I will say the 'A' monitor has color problems, the 'B' won't turn on. Try the 'B' LCD panel with the 'A' cards. Swap cards back and forth until you determine which cards are defective, then start troubleshooting.

PlainBill

[mr_mooray]

Re: 2 x Samsungs 2493HM - Double the Trouble!

Great help with putting me on track on swapping things around - I now have one fully working monitor. I put board A into housing B and now everything works perfectly.

With regards to the remains, I presume the cables/other parts of the housing was causing the color problem and the menu not showing up. Not sure what to do now. I will try and put a new cap on the board and connect up and see what happens.

[PlainBill]

Re: 2 x Samsungs 2493HM - Double the Trouble!

Great help with putting me on track on swapping things around - I now have one fully working monitor. I put board A into housing B and now everything works perfectly.

With regards to the remains, I presume the cables/other parts of the housing was causing the color problem and the menu not showing up. Not sure what to do now. I will try and put a new cap on the board and connect up and see what happens.

Correct. By swapping parts around you can identify exactly which boards are the source of the problem. If it's the LCD panel, a successful repair is unlikely. If it's the signal card, a successful repair may be possible.

PlainBill

[mr_mooray]

Re: 2 x Samsungs 2493HM - Double the Trouble!

I tried to put a new cap on, put everything back togerther and now the LED wont even come on. Considering that this monitor also had problems with color and the menu wasnt working I am thinking of taking my losses and moving on. Thanks for all the help Im glad that at least I got one working perfectly.

I might have a look and see if I can see this model being sold as defect for cheap, then buy it and see if I can fix it with these old parts as well as buying new caps.

[PlainBill]

Re: 2 x Samsungs 2493HM - Double the Trouble!

I tried to put a new cap on, put everything back togerther and now the LED wont even come on. Considering that this monitor also had problems with color and the menu wasnt working I am thinking of taking my losses and moving on. Thanks for all the help Im glad that at least I got one working perfectly.

I might have a look and see if I can see this model being sold as defect for cheap, then buy it and see if I can fix it with these old parts as well as buying new caps.

Ahem, if you will excuse my saying so, you give up too easily. If you have a DMM, it's time to begin troubleshooting. Believe me, the thrill of taking parts from two monitors and making one complete one is nothing compared to the fun of actually figuring out what is wrong with a board and fixing it.

PlainBill

[mr_mooray]

Re: 2 x Samsungs 2493HM - Double the Trouble!

OK

I tried to put a new capactior on the "exotic board" and put everything togerther. Now nothing turns on. I think I probably didnt solder on the cap right.

You mentioned cleaning the board but I dont think I quite understood it. There seems to be some clear residue on the board. One problem I had even though I read some soldering guides:

I preheated and tinned the solder point I have a 15/30w switch solder iron which I put on 15w. I touched the component lead and the area I wanted to solder on and left it on there for a while (perhaps not long enough? - How long?) I then applied the solder to the component lead and solder pad but not my soldering iron, however it didnt want to stick and just leaped towards my soldering iron

You also mentioned scrap the solder resist away, could you show me on the pic ? as there is green, dark green and then the firbre glass board.

[ipman]

Re: 2 x Samsungs 2493HM - Double the Trouble!

That dark green thing is is to be cleaned. Scratch without putting pressure on it. Underneath it you will find shinny copper.
Be sure to use flux to solder.