LG W2234S Repair Help...

[senndogg]

Re: LG W2234S Repair Help...

hi retiredcaps, i didnt notice anything strange after the ROM flashing, the monitor just came back to life. i havent used it before, since it wasnt mine, but the owner said everything was ok. we tested it for several hours and i even liked the picture quality of the cheap Innolux panel
it seems strange to be software related, but if you are able to flash it to the ROM i have posted, you should try!

[retiredcaps]

Re: LG W2234S Repair Help...

its working great!

How do you find the picture quality? Normally, I'm not picky about picture quality, but my W2234S is noticeably worse than most even after adjustments including a complete factory reset. The constrast is particularly poor.

[senndogg]

Re: LG W2234S Repair Help...

Hello people,
its been a month i dont enter the forum because of an internet malfunction, and now lets get down to business, seriously!

this LG i have was completely dead. no signs of life.

measured the voltages. 5V ok. tested with a 2W lamp, ok, no voltage drop.

measured the regulators in the main board. 3.3V ok, 1.8V ok.

measured the voltage in the power button. 3.3V.

at this point i searched THIS forum and heard about the firmware problem.

as i dont have much time for the chip to be shipped from china, i found the FW online, and i want to share it with you.

went to a friend of mines, who has a ELNEC programmer, and the procedure was routine for him. it took 5 minutes to unsolder it, to test-read it (found it was corrupted), to rewrite the .bin file, and to solder it back.

its working great!

thank you guys and i am pleased to help!

[retiredcaps]

Re: LG W2234S Repair Help...

I forgot to add that my particular monitor does NOT automatically discharge the large filter capacitor. The cap still held 165V DC overnight and I had to discharge it with a 100K ohm resistor.

Normally, there is a bleeder resistor and maybe mine doesn't have one or it is not working? Anyway, my lcd is all put together and I have no plans to take it apart again.

[retiredcaps]

Re: LG W2234S Repair Help...

Found one from ebay that HAS been programmed... How does this look?

http://www.ebay.ca/itm/MX25L1005MC-F...#ht_1580wt_907

I picked up this monitor a while back, but didn't get around to it until I got some decent tools.

I can verify the above seller, monitor-09, ships a chip with the flash programmed in it as I just did the same repair. The menus are in Chinese so you will have to fiddle around with the OSD menu settings until you see English.

Beware of another ebay seller that sells the "same programmed" chip for about 1/2 the price. I bought it and it didn't work and then I found out I bought a blank chip even though their ad clearly states it is programmed with the firmware. I pointed this out, but their ad still says it comes pre-programmed. I got a refund, but I put my logic board at risk unnecessarily (see below).

For removing the old SMD IC, I used a non temperature control hot air gun and protected all the surrounding areas with Kapton tape. It only took about 30 seconds to remove the old one. I also used lots of flux to help solder in the new IC.

My first SMD chip repair!!!

The monitor is now under going real world tests.

PS. This monitor has no screws holding the metal cage to the plastic and the lvds cable is super short so be careful taking it apart.

[docksteaderluke]

Re: LG W2234S Repair Help...

Hey guys...

Sorry for the late reply, but I finally got the part (MX25L1005MC with firmware) and replaced it tonight and the monitor works like a charm !

Thanks for all of your help. I hope this solutions helps you out Tim (and all others who have a similar issue).

[docksteaderluke]

Re: LG W2234S Repair Help...

Hey Tim,

I'm still waiting on the part (shipping from China is SLOW). It should be here within the next 2 or 3 days. As soon as I try it out I'll post back here to let everyone know if it worked.

[pattontj]

Re: LG W2234S Repair Help...

Plainbill, just wondering how you made out with this issue. I have a friend who has the exact same monitor, and his symptoms are almost identical to yours. The monitor turns on, LED goes blue, the LG Logo comes up, then it all goes black after about 2 seconds, and repeats. However, in this case, it only seems to do it after the computer goes to sleep, or if you try to change the resolution. If that happens, the computer needs to be powered off, then the monitor powered off, then turn on the computer and wait for it to get into Windows, THEN power on the monitor.

Works as a workaround for now, but it's probably only a matter of time before the monitor completely dies as yours has. Let us know :-)

Tim

[PlainBill]

Re: LG W2234S Repair Help...

Found one from ebay that HAS been programmed... How does this look?

http://www.ebay.ca/itm/MX25L1005MC-F...#ht_1580wt_907

That should do it. They describe the precise symptoms, and have 100% positive feedback.

PlainBill

[docksteaderluke]

Re: LG W2234S Repair Help...

Found one from ebay that HAS been programmed... How does this look?

http://www.ebay.ca/itm/MX25L1005MC-F...#ht_1580wt_907

[PlainBill]

Re: LG W2234S Repair Help...

i think its a transistor or high voltage transformer failure

On the logic board?

PlainBill

[alf_red007]

Re: LG W2234S Repair Help...

i think its a transistor or high voltage transformer failure

[PlainBill]

Re: LG W2234S Repair Help...

Does anyone know if there is any way to test the MX25L1005MC flash IC on the logic board? I can't find a full blown logic board replacement but this IC seems to be an issue with some...

I'm afraid you are SOL on that. Most GPUs bootstrap firmware from an external chip. That chip will usually be identified by marking it with paint. If the contents of the chip gets corrupted, you will get the symptoms you describe. And the MX25L1005MC dies have a blue dot on it.

Someone had a similar problem; he was able to find a copy of the firmware, rig an adapter and reprogram the chip. This could best be described as a non-trivial task. There are a few companies supplying chips preloaded with firmware, however I have only seen this for chips that are in sockets.

I've got a monitor on the shelf with the same problem. What irritates me is the corruption is avoidable. Certain parameters are stored in the firmware chip, rather than in the user eeprom. When the caps go bad a noise spike during a write cycle will corrupt the firmware.

PlainBill

[Rtech]

Re: LG W2234S Repair Help...

I got one from Ebay UK at a huge £35,and that was the last one the Seller had, the others he did have were sold out !!!

[docksteaderluke]

Re: LG W2234S Repair Help...

Does anyone know if there is any way to test the MX25L1005MC flash IC on the logic board? I can't find a full blown logic board replacement but this IC seems to be an issue with some...

[docksteaderluke]

Re: LG W2234S Repair Help...

k. So I hooked it up to the 17" LCD panel and the backlight turns on (all white) then off. So it must be the logic board for sure now. I don't think it's a short in the inverter since I swapped it for a new one and it still did the same thing.

So any ideas on where to source a new logic board?

[PlainBill]

Re: LG W2234S Repair Help...

Still flashing on and off (LG Logo displayed on the screen for a second or two... then everything turns off) with the front button panel disconnected from the logic board.

Any idea where I can source a replacement logic board? I figure I may as well start looking now but can't seem to find anything via google/ebay...

Are the voltages coming from the inverter pretty much standard across the board? I have an old 17" Samsung that I might hook up to the LG PSU to see if the display keeps turning on or off. That way I'll know if it's the logic board or the backlight.

The key is the power light. With one exception, when the backlights go off the power led will stay on. The power LED is switched off and on by the processor on the signal card.

The one exception is if there is a shorted driver in the inverter, and the short overloads the power supply, causing it to shut down.

PlainBill

[docksteaderluke]

Re: LG W2234S Repair Help...

Still flashing on and off (LG Logo displayed on the screen for a second or two... then everything turns off) with the front button panel disconnected from the logic board.

Any idea where I can source a replacement logic board? I figure I may as well start looking now but can't seem to find anything via google/ebay...

Are the voltages coming from the inverter pretty much standard across the board? I have an old 17" Samsung that I might hook up to the LG PSU to see if the display keeps turning on or off. That way I'll know if it's the logic board or the backlight.

[PlainBill]

Re: LG W2234S Repair Help...

^ That's kind of what I was thinking, identifying the on/off pin.
And then if needed with switch disconnected take the voltage on that pin low, and see if the monitor stays on.

But even that isn't necessary. LCD monitors usually remember their last state; the power button is just a momentary contact. If the cable to the front panel is disconnected and the monitor still is cycling on and off when you apply power, the front panel switches, pc board, led, etc are not responsible. If it comes on and stays on, or in never comes on, we know the problem is in that portion of the circuit - as you said, probably a stuck switch.

PlainBill

[alexanna]

Re: LG W2234S Repair Help...

^ That's kind of what I was thinking, identifying the on/off pin.
And then if needed with switch disconnected take the voltage on that pin low, and see if the monitor stays on.