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View Full Version : cost to fix blacklight on lcd monitor?



goodiesguy
17-12-2011, 07:10 AM
My main desktop monitor (working fine Yesterday!) has decided this morning that the backlight is not going to work. How much would it be to fix this if i don't get it going again? (could it be the cold weather fiddling with it?)

It's a Samsung SyncMaster720n. and it's 17".

Speedy Gonzales
17-12-2011, 07:37 AM
Same thing happened to one of mine. Last time I turned it on, it took like 10 times to turn the thing on. I think the power inverter was buggered. In the end I biffed it

The Error Guy
17-12-2011, 07:57 AM
Depends what died, the Cold cathode tube or the inverter. Depending on time/skill/money you can find out the model of the LCD panel and replace that, find the cathode tube part number and replace that or replace inverter. Some cathode tube replacements will come with new inverters.

All failing sell it. me and a mate use damaged (that still have a good LCD) because we strip them down for our MT table. Water damage is good since the diffuser layers bubble but we dont need them, we put in a Rear DI layer. Get rid of all the backlight/DI layers and just use the panel. Only thing is we need working hardware that goes with it (basically the LCD's "motherboard", all its control circuits etc)

Nomad
17-12-2011, 11:18 AM
Can be labour intensive. Youtube.com may has videos to install. You can get the part on TM or eBay, eBay might be $25US ex. postage :confused:

Someone else doing it can be labour intensive and the part might cost ya $100.

Maybe upgrade to LCD :D

CliveM
17-12-2011, 01:54 PM
Probably cheaper and certainly quicker to just replace it. They are fairly inexpensive nowadays.

pctek
17-12-2011, 02:40 PM
hard to say, had a laptop screen repaired once and it was $220. Probably not worth it for a monitor........

Paul.Cov
17-12-2011, 07:24 PM
I've personally repaired a bunch of HPs (BenQ boards) for about $5.00 each.
Depends on what failed however.

The HPs I've been able to fix had visibly bad caps and roasted picofuses (baked right off the board in one case... no solder left on it, and the printed circiut peeling away from the heating)

This problem is typically near the top of the board, where caps have been placed too close to heat sinks.
Stains on the board may also reveal blown caps.

Odds are the guts of your monitor are BenQ as well.

icow
17-12-2011, 07:44 PM
I got a 17" screen (LCD) for $60 a year ago. Keep that in mind when looking for parts.

Agent_24
17-12-2011, 09:18 PM
My main desktop monitor (working fine Yesterday!) has decided this morning that the backlight is not going to work. How much would it be to fix this if i don't get it going again? (could it be the cold weather fiddling with it?)

It's a Samsung SyncMaster720n. and it's 17".

Can you still see a picture if you shine a torch on it for example or is the thing totally dead?

According to this: http://www.badcaps.net/forum/showthread.php?t=6792 that model's PSU uses Su'scon capacitors which are rubbish. Could be part of the problem...

dugimodo
17-12-2011, 10:11 PM
No Idea but I know pbtech sell 2nd hand monitors that size quite cheap all the time.

goodiesguy
17-12-2011, 10:16 PM
Can you still see a picture if you shine a torch on it for example or is the thing totally dead?

According to this: http://www.badcaps.net/forum/showthread.php?t=6792 that model's PSU uses Su'scon capacitors which are rubbish. Could be part of the problem...

Yes, i can still faintly see the picture, but it's extremely dim. that's why i thought it would be the backlight.

Paul.Cov
18-12-2011, 09:32 AM
Yes, i can still faintly see the picture, but it's extremely dim. that's why i thought it would be the backlight.

Chances are the backlight tubes are fine, the problem will lie with the circuit that powers those tubes, which is prone to blowing parts. I've seen many like this. If you're lucky, and have the courage to pull it apart and weild a soldering iron you may be able to fix it for peanuts.

Typically there's two tubes, one at the top, one at the bottom. If both suddenly seem to die together its more likely to be their circuit rather than the tubes themselves.

goodiesguy
18-12-2011, 10:18 AM
I have no idea how to pull it apart, as there are no screws to do so.

Paul.Cov
18-12-2011, 01:14 PM
Lie it face down.

Usually there's 4 screws holding the stand to the rear - remove them

In most cases the bottom corners have a screw to remove. Even then, there's the need to prise it apart - use something broad, thin, blunt... a butter knife / putty knife. Sometimes better to use two at once to spread the forces... simly start levering the edges apart. There's hidden plastic clips all around the edge. They'll start to pop open, and it gets easy from there.

Better to start at the bottom where any minor edge damage won't be seen during normal use.

Don't stick the knives in deep... 2-3mm is ample.

Once inside take care with the ribbon cables - there's various ways they're secured in place. Sometimes the locking bit folds out, other times there's a lug on each side to prise up.

Agent_24
18-12-2011, 02:17 PM
Screws can also hide under labels and under plastic or rubber caps.

icow
18-12-2011, 03:03 PM
Especially ones that say warranty void if removed :p

goodiesguy
19-12-2011, 08:29 AM
Not gonna bother with it, though i might open it up.

I just scored this monitor on trade me for $52 with free shipping: http://www.trademe.co.nz/Browse/Listing.aspx?id=431638067

And I think my samsung lasted well considering a ten year old found it in a skip, then gave it to me a few days later (this was 2 years ago). my samsung also had a few scratches on it etc..

From reading the specs of the one i've won on TM i think i read it has a dvi imput, so that would be i can get a dvi cable and no longer have to use Dvi to vga for my main monitor.