Top half of LCD screen gone dark

D

d7e7r7

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So I have a Samsung SyncMaster P2350 LCD screen and the top half of my screen has gone dark.

9840872_600x381.jpg


I don't know how it is constructed, could the top tube have blown or do LCD screens not use tubes or only use 1 tube?

I have tried different cables and tried connecting the screen to my netbook, same problem, so it's not a cable or graphics card problem...

Has anyone experienced this before? Who could I take it to, to be looked at?
 
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It could be that 1 of the flourescent lights in the array behind the LCD panel has gone.

Should be easy enough to have it replaced at a Samsung repair agent. Phone Samsung in Cape Town and ask where theie repair centre is.

Consumer level LCD monitors using LED (a.k.a. WLED) backlight are all edge lit. LCD monitors using CCFL (florescent) backlight are all full arrays. That means the florescent lamp spans from on side of the monitor to the other. Cheap LCD monitors with CCFL uses as few as two florescent lamps. Large, expensive LCD monitors with CCFL can use as many as 6 lamps to the best of my knowledge.
 
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So I took it in to Samsung repair centre today and they said it needs a new power supply board (Samsung BN44-00297B) and this (cost R424.22) including labor (cost R307.02) will come to R833.61

Now do you guys think it's worth getting it repaired at that cost or scrapping it and buying a new monitor?
 
Ouch. Depend if you want to upgrade or if you're happy with your current screen. A good screen is quite expensive these days, not sure how much yours would cost new though.
 
Well a new LED technology screen would be nice but I don't want to downsize and everything 23.5" and upwards is almost double the repair costs...
 
d7e7r7 said:
Well a new LED technology screen would be nice but I don't want to downsize and everything 23.5" and upwards is almost double the repair costs...
Click to expand...

How old is your screen and how long will they guarantee the repair? Is your screen still usable? If so, you could probably get a couple of hundred bucks for it as it is. Take that and your repair money..... See where I'm going?
 
Have you got some pictures of the power supply board?　Personally I would look at that carefully and try to replace anything that looked faulty.
 
Some cheap LED backlit screens don't render colours as accurately as CCFL backlit displays, so it might be worth repairing the screen that you have, but go look at LED backlight screens on display at one or two computer shops - the technology has come a far way the past two years or so...
 
I double I'll be able to sell it for much seeing as it's broken and needs a new power supply board...
I don't have any pictures of the inside as it is with the service agents.

Think is, they say it'll take at least 2 weeks to repair (need to order part), I don't have a spare monitor so it means I'll be with computer for 2 weeks :(
 
d7e7r7 said:
I double I'll be able to sell it for much seeing as it's broken and needs a new power supply board...
I don't have any pictures of the inside as it is with the service agents.

Think is, they say it'll take at least 2 weeks to repair (need to order part), I don't have a spare monitor so it means I'll be with computer for 2 weeks :(
Click to expand...

Please let us know how it turns out. I'm a bit surprised that they say it needs a psu. I've repaired say 3/400 monitors over the years and it seems a bit odd. The job of the power supply is to provide carefully regulated stepped-down dc voltages. I can't see them devoting two separate psu circuits (one for the top half and one for the bottom) to the backlighting of the screen. As another respondent pointed out, its more likely that part of the backlighting system itself has failed. I should add my repair experience is limited to the older CRT monitors but I have repaired the PSU on one of my own Samsung flat screens. What I'm saying is the psu may arrive only to have them fit it and the problem is still there. I'm under the impression the monitor still works apart from being dimmer on the one half of the screen - or have I got that wrong?
 
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Initially the screen was dark at the top half and the bottom was fine, then recently the display would come on for about 1 second then go off again, it would come on and go off no matter how many times I turned it on and off but would only stay on for about a second.
 
chrisdc said:
Please let us know how it turns out. I'm a bit surprised that they say it needs a psu. I've repaired say 3/400 monitors over the years and it seems a bit odd. [...]I can't see them devoting two separate psu circuits (one for the top half and one for the bottom) to the backlighting of the screen. As another respondent pointed out, its more likely that part of the backlighting system itself has failed.
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I have disassembled cheap LG monitor before me. It has combined power supply for control board and two CCFLs. Yes, each lamp is driven by dedicated circuits generating high voltage. So it is possible that single circuit failed. Situation gets complicated, it looks like a main chopper MOSFET is partially damaged and needs to be replaced, a reason is here:
d7e7r7 said:
Initially the screen was dark at the top half and the bottom was fine, then recently the display would come on for about 1 second then go off again, it would come on and go off no matter how many times I turned it on and off but would only stay on for about a second.
Click to expand...
 
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sajunky said:
I have disassembled cheap LG monitor before me. It has combined power supply for control board and two CCFLs. Yes, each lamp is driven by dedicated circuits generating high voltage. So it is possible that single circuit failed. Situation gets complicated, it looks like a main chopper MOSFET is partially damaged and needs to be replaced, a reason is here:
Click to expand...

Would the poster be able to purchase a suitable replacement MOSFET for his Samsung monitor locally at a decent price? Maybe worth a try before shelling out R833!
 
Yotch said:
Would the poster be able to purchase a suitable replacement MOSFET for his Samsung monitor locally at a decent price? Maybe worth a try before shelling out R833!
Click to expand...
I am afraid, not. Samsung will replace entire board, unless fault is very obvious. I mentioned MOSFET as a possible secondary damage due to overload (overheat) in result of initial fault, not an initial cause.
 
FFS Samsung!
:mad:
Open the back of your tv and look for bulging,leaking or blown capacitors, remove them and acquire replacements and solder them in.

What Samsung is not telling you is that they built a million of these tv's with the wrong capacitors and they will only last a minimum of 2-3 years and then blow.The exact same thing happened to my tv and was told the same thing by Samsung repair center.I repaired my tv for R50 worth of capacitors.

here is the worldwide recall, dont bother telling Samsung SA about this - they claim ignorance.

http://www.dailytech.com/Samsung+to...ts+Over+Mass+LCD+TV+Failures/article24065.htm

If you google you will find millions of people with the same problem.
 
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sajunky said:
I have disassembled cheap LG monitor before me. It has combined power supply for control board and two CCFLs. Yes, each lamp is driven by dedicated circuits generating high voltage. So it is possible that single circuit failed. Situation gets complicated, it looks like a main chopper MOSFET is partially damaged and needs to be replaced, a reason is here:
Click to expand...

I stand corrected. And yes, the additional info does point to other problems. Would you agree that fitting a new PSU will not necessarily make the problem "go away"?
 
Yotch said:
Here are some pics of the board. I would be tempted to do some tests with a meter ...
http://www.google.co.jp/imgres?imgu...a=X&ei=2SWfUuyLG8-Z0QWuwID4Bw&ved=0CDgQ9QEwBQ
This board has been repaired - it would be interesting to see the underneath as you could probably see what has been replaced ...
http://www.ebay.ca/itm/Samsung-2433...s_Parts_Components&hash=item19e457668a&_uhb=1
Click to expand...

The caps look fine. They have been sensibly placed well away from the hot running stuff. That's not to say they are ok, just a gut feel. Could be a shorted diode, dry joint, failing anything really, or possibly something on another board altogether. That's where the agents do have an advantage. They may have another identical set they could try this PSU in.
 
Yotch said:
Would the poster be able to purchase a suitable replacement MOSFET for his Samsung monitor locally at a decent price? Maybe worth a try before shelling out R833!
Click to expand...

I got the FET I needed for mine from Mantech. But sajunky is right, if something else caused it to blow, it will just blow again - and maybe take something else with it. If the OP is prepared to gamble....? This is what I call a classic "Dirty Harry" situation. You need to ask yourself, "Do I feel lucky?" :)
 
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