DELL U2515H 1440p Monitor NOT WORKING - Can I FIX it?

Hi Vince, a few things. To find a mosfet online, wherever you see an "N" in its number, there will generally be two numbers preceding it and two numbers following it (sometimes there will be other letters like M or L as well). In this case, it is 15N15. These two numbers generally are supposed to represent Drain source voltage, and drain current, and the letter N represents N-channel. Some manufacturers can make it confusing though, but you can use this as a guideline. There are other naming conventions as well for mosfets, like 2SK, IRF, etc. The mosfet that you chose - IRF510 - will work, but not sure for how long. It is drastically underrated, the IRF510 is 5A drain current vs the original 15N15 is 50A. The voltage is underrated as well, and the capacitances are wildly different (in a switching power supply, capacitances of switching FETs are important) - Ciss (input capacitance) of the IRF510 is 180pF vs 3560pF of the 15N15, gate charge is 8nC vs 63nC, etc. This can affect duty cycle and "dead time" in switching transitions, rise times, ringing, and even create unwanted resonances in the circuit. When you start using more than one switching FET, such as in a push-pull circuit or a half bridge, these capacitances become even more critical. In your little box of FETs there, the IRF640 would be a better choice, as many of its specs are closer to the original, though capacitance are still somewhat off and it is only 15A rated. Also, transistors in this style are a TO-220 package. If you are looking for a transistor with an insulated tab instead of the metal one, this would be TO-220F or TO-220FP.

Vince is so honest. I think it’s VERY important to recognize when we don’t know how to fix things BUT, what he does is even more important cause he tries again and again even if it’s just for learning. Congratulations for videos like these ones when we all end up learning something

This has got to be one of my favorites! A lesson for being methodical and just trying stuff.

This video saved me $200 and kept one more monitor from becoming e-waste. My monitor had a different problem (blown fuse) but the diagnostic procedures in this video taught me what to check. Thank you.

Hi Vince there is a guy called Sorin who works in a repair shop in London. He runs a YouTube channel called electronic repair school. He has numerous videos that take you through diagnosing SMPS boards. I'm about the same level as yourself on electronic fault finding and Sorin's videos have been a massive help in teaching me to understand how a SMPS works and how to fault find. He also uses very basic tools and a multimeter. Seriously well worth watching. Keep up the good work Vince I really look forward to your videos.. Cheers Baz

I confess to cheating on a similar problem once, with a TV. I noticed that the 12v (on that model) was missing, so I just bought an off the shelf 12v PSU unit and built it in instead! Well done, Vince.

Great to see someone willing to put the work in and fix something. What a great example of the ridiculous state we are in that things we buy if they break down are just throw away and replaced. A friend of mine works at a Dyson returns place in Gloucester and he tells me virtually all of Dyson returns are scrapped - very little is re-used, and some of the returns are from stockists so have never even been unboxed but because they have not sold are outdated. Hundreds of thousands retail price of goods scrapped. It is really disgusting.

Nice fix Vince! By the way; I have used similar models at my office for many years, and my primary monitor (Dell 24") is now 10+ years old. If you want audio on the screen you can check for original soundbars for your particular model, as several of Dell's models support this. A quick search indicates that a soundbar with the designation AC511 should be correct for your monitor. The blanking panels that you removed from the bottom is there to hide the mounting brackets for the soundbar.

The UltraSharp monitors are some of Dell's good ones! I have the 27" U2715H and it is awesome! The little stick-on covers on the lower edge are intended to cover the clip points for the Dell SoundBar.

Superb fault finding on this one, Vince. I hope it carries on working for many more months to come! I wonder whether you could get a nylon screw to secure the mosfet? Not sure if that would work, but the cable tie option is usually a good one! 👍

Oh, we have thousands of these monitors at my job. I work in our IT department as our Mac Administrator. Usually we toss them because people crack the LCD panel, I don’t recall us ever having one with a failed power supply.

Not many better feelings in the world than you fix something in this way yourself! Good work

Vince you can get T0-220 insulating kits for those transistors. They are cheap and adding a little thermal paste to the mica on both sides transfers the heat without conducting.

You can use a plastic screw insert and clear fiber insulator to secure the mosfet to heat sink. This is commonly used in many ground sensitivity components 😊

Really enjoyed this one Vince. I Had an Ultrasharp years ago which I used for photo editing as it was colour calibrated. Best monitor I ever had. It broke in a similar fashion to this and I've never found one quite as good for colour accuracy.... Wish I'd tried to fix it now, lol.

Really Nice video Vince Your videos inspires me to keep going on my small channel. I can still remember when you didn't even know what a power rail was but you never gave up . Great deduction on the mosfet value. switch mode power supplies are a pain to work on! keep up the great work .👍

One thing I noticed that you are cleaning the device with much care 👍,I can feel how much passionate you are. That shows you are a very good technician.Keep up the good work 👍👍👍

Looks like the original MOSFET is a Cystech MTE015N15RFP. If you look at the last page of the datasheet, the markings are the same and the last line 6M03 would be the date code (6 = 2016, M = December, maybe, this seems a little too close to the Jan 2017 date on the monitor though!). Doesn't seem available to buy in small quantities but maybe that will help in finding a suitable alternative if you ever need one!? Great fix anyway!

You channel cost me money, whenever i watch one of your videos i end up buying a project. Recently fixed 7 elgato capture cards and a few ps5 controllers!

Still have three of those Ultrasharp U2515Hs in a triple monitor setup today. Been using them since 2015 and they're still going strong. Great to know about that MOSFET as a potential weakness, hope I never need to replace the ones in mine, but if they were to fail, at least I'd have some place to start with repairing them :)