Dell P2312H Backlight Repair

In this video, I replace the backlight on a 23" Dell monitor (Model P2312H) which has started turning pink from age.
This is a common issue with these monitors as they get older with lots of hours on them. While this specific model turns pink, some others can turn other colors like yellow or red if they use the older CCFL style lamp, which can be a lot more difficult to repair.
If you have a pink monitor with lines or picture glitching, that's usually a sign of a bad TCON board, which requires a different repair not covered in this video.
Parts used for this repair:
297mm LED backlight module - www.ebay.com/sch/i.html?_from...
4mm double sided tape - www.ebay.com/sch/i.html?_from...
Boxer screwdriver set - www.ebay.com/sch/i.html?_from...
Other tools I use:
Weller 40W soldering station - www.ebay.com/sch/i.html?_from...
ZD985 desoldering station - www.ebay.com/sch/i.html?_from...
Hot air + soldering station - www.ebay.com/sch/i.html?_from...
8x Desk magnifier - www.ebay.com/sch/i.html?_from...

[@user-rw6iq8lt8p]

thanks! I am appreciate your very valuable advices! have a good one!

[@hypermice]

Thanks so much! This was super easy to follow along and deconstruct my monitor. I didn't have a new LED so I put it all back together, (I was trying to see how hard it all was and if I could do it myself,) and the dark part of my monitor is no longer there. I guess a wire somewhere was loose and unplugging everything and putting it all back together fixed it.

[@GGigabiteM]

The LED backlight has at least two parallel arrays of LEDs to keep the voltage down. If there was a bad connection or a marginal LED in only one of the parallel arrays, you can indeed get dark areas on the screen.

[@raghunathankoundinyasubbar9975]

My P2412 is working ALRIGHT for about an hour Then a thermal upshoot near the regulator SWITCHES OFF the DC for backlit. I am sure a maestro like U can publish tips to change the component.I am 86 and continous on hand mulitimeter/soldering iron experience I amSURE there is a component a Capacito ot IC which causes the problem CAN U GUIDE ME SIR?

[@GGigabiteM]

If the monitor is staying on while the backlight is off, there are still several potential failure modes. The LED backlight module could have a marginal LED that is going open when it gets hot, which would kill the whole module since all of the LEDs are in series. Another potential failure is if one or more of the LEDs shorted out, it could cause an increase in current draw and make the driver go off on overload or thermal cutout. The backlight driver itself could also have failed in numerous ways. Since there are no schematics available, you'd have to have the power board exposed when the fault occurred to be able to do any testing. You have to be very careful when doing testing like that though, because there are nasty high voltages all over the board, both AC and DC. The backlight voltage was something like 56v IIRC, in addition to the SMPS and mains voltages which are even higher. The safest thing would to have it on an isolation transformer, unless you're comfortable poking around on super spicy circuitry.

[@jfsd2000]

My dell 2311hb is turn yellow and dark,I think its backlight problem too.But is seem hard to change it.

[@GGigabiteM]

Your monitor uses the older CCFL style backlights. When these start failing, the ends usually go black and sometimes burn through the glass envelope and start arcing to the chassis. Changing these can be a bit more challenging because they're often in a metal carrier that needs to be removed to change the CCFLs out. I'd recommend an LED retrofit kit which comes with LED strips and a driver. These last far longer and use a whole lot less energy and produce less heat. You'll have to carefully disassemble the LCD panel to get the CCFLs out. There are multiple layers of polarizing sheets and an acrylic diffuser in a sandwich with the LCD glass, you'll want to keep these together and not separate them. This reduces the risk of getting dust between the sheets that can show up as artifacts later. You'll also want to wear gloves to keep oil from your skin contaminating the sheets.

[@jfsd2000]

Thank you very much.I'll try to do it.

[@slobodanljubisic]

My Dell U2312HM turned into red/pink tone on the right side of the screen only, and that happened over the night. (The night before everything was ok, next morning that happened). And there is some flickering on that right side too. This method will help in my case as well?

[@GGigabiteM]

While both mine and your monitor look the same externally, I can't tell you if they're the same internally since the model numbers are different. The failure mode you describe automatically makes me think your monitor is different internally due to it only flickering on one side of the screen. The monitor in the video only has one backlight strip on the right side of the screen, so if it failed, it would make the entire screen flicker, not just the right side. If the backlight is worn out, changing it will fix the problem you have. But you'll have to do some diagnostics to make sure something else wasn't causing the problem, like a bad power supply.

[@slobodanljubisic]

@@GGigabiteM Many thanks!

[@tautvydaskirsys6420]

Same has happened to me. Did you attempt the repair? did it work?

[@slobodanljubisic]

Attempted to repair, but in the service they told me it is panel that is in fault... and that repair is not cost effective.

[@tautvydaskirsys6420]

I see, thanks

[@eduardlnagr720]

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