Dell U2412m Schematics?

[Jlryan]

Hello everyone, new to the forums!

So, about a year ago my U2412m regrettably died... Just up and decided to switch itself off while I was editing a photo, and never returned to life. Looks like a fault with the PSU, and after disassembling and testing, the moment I plugged in to test, several SMT resistors and a transistor blew (quite literally, showing me with glorious magic smoke and shards of silicon. Unfortunately because of this I have no idea of identifying either the TO-220 (or SOT186) or the resistors to replace.

I love this monitor, and would be so happy if I could get it working again, as I don't want to fork out another £200+ for a monitor unless the 4K ones come a little cheaper.

If anyone can provide a schematic for this PSU board, or if you know where I can get one, that would be really appreciated.

A few pictures for ID:













Best regards,

Jamie

[MK14]

You can probably get replacement PCBs on ebay for about £10 to £20 or so. Some on the UK site (maybe), others internationally.

Expired (i.e. auction finished) one:
http://www.ebay.co.uk/itm/Dell-Power-Supply-Board-4H-1GH02-A02-for-a-U2412Mb-24-Inch-LCD-Computer-Monitor-/181482518225?nma=true&si=mf0WeZbQ8FdbZWH7SKj2LpHCYIE%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

[Jlryan]

Yeah I had already looked at doing something like that before, problem is it's mostly all international with £10 - £20 postage on top of the £10 - £20 board, then import fee's on top of that after, could end up spending as much as £50 for a PSU. With that this will be my absolute last case/choice in repair.

Thanks though!

[wraper]

You can use 6A 600V-700V N channel mosfet like STP6N60, missing resistor on it's gate (R611) can be safely changed to something close to 10R. All other SMD resistor values seem to be readable. The problem is, as mosfet exploded, PWM controller (IC in SO-8) most likely is dead too and need to be replaced. If you replace the components, don't connect it to the mains directly. Connect some ~100W incandescent bulb in series which will protect it from exploding again if something faulty didn't get fixed.

[wraper]

BTW check big resistor R615 which is connected to the source too. It could fail open due to the high current, it's value is 0.82R.

[twinsen]

I have the same model but different label on the PSU board:
https://www.eevblog.com/forum/repair/dell-u2412mb-dead-(no-lights-at-power-button-no-back-light)/

Q601 on my board is K4101.

By the way, R615 on my board seems to be 0.39R but don't know the Watt rate and type.

[singapol]

Frankly I wonder if your skills are adequate to do repairs. If you really want to take this as a tutorial ask twinsen if he can read out the part numbers for you like power mosfet,pwm ic underneath and the resistors.
Read up on swichmode power supply theory. Since photography is your passion I doubt you want to spend so much time to do this repair and I wonder if it's worth it. Consumer products like these are made to the lowest costs and are not meant to last. Best is to bite the bullet and buy another one so you can enjoy your photography. PS there could be very high voltages in there and I'm not kidding.