U3011 power fault?

[ktzz]

hi,

not sure where should i start

i got two dell U3011. both with the same problem!

here is what happened to my monitor. pixels are alright, panel are perfect but after using it for maybe like 1 hr or so, it start randomly power off. totally no power.
The only method i can do unplug the power cable, then wait and re plug back in. but the time get shorter for monitor's power to stay on.

i tried looking for bad caps, but i found none. what seem to be the problem?

and i have this weird blue wire connected here.





lastly i really cant find anything that had gone bad. only this. the colour look different.




so what seems to be the problem with it?

Thanks!

[leggot]

Re: U3011 power fault?

Hi ktzz,

The first thing that I would check would be the voltages coming out of the power board, I see pins for 24v and GND and ensure that the power board is infact outputting voltage when the set turns off. This should be done when the unit is function correctly and after it has turned itself off. The lack of 24v at either time may indicate a faulty powerboard.

There should also be a pin from the main board to the powerboard that send the signal to power on (usually 3v), I am unable to identify it from the photos, but it would be worth testing that to ensure that the main board is telling the power board to output power.

Also, part numbers for the board would also be helpful.

[ktzz]

Re: U3011 power fault?

oh the part for this u3011 power supply board is PS-2201-3-HF

btw im really new at such thing, is there any website that teach me how to test for the 24v?

thanks leggot!

[leggot]

Re: U3011 power fault?

Hi Ktzz,

You may want to reference: https://www.youtube.com/watch?v=XH9GfkGQX1I

You will need a multimeter and you want to be careful about testing the panel while it is on. Be careful of what you touch, there are high voltages and be careful not to short anything.

Basically put the multimeter into DC voltage mode and touch the red connector to the 24v pin and black connector to the gnd pin. Record the voltages displayed on the multimeter when the set is functioning correctly and when it has automatically turned itself off.

[ktzz]

Re: U3011 power fault?

hey! thanksonce again! i will try to get it measure as soon as im free.

oh ya btw what is that blue wire from the power supply board to another logic board? i saw alot of example but none of them has it connected like that.

[ktzz]

Re: U3011 power fault?

hi all just wondering if i get the power supply board changed to a new one, will it be a good choice?

[ktzz]

Re: U3011 power fault?

okay i think i found the problem. i have not take out the board but anyone know how to solve thing? btw the blue wire is for what? lol



which is same as this i suppose. coz of the size and almost same digit at the end.

[ktzz]

Re: U3011 power fault?

anyone know where to find this board?



thanks!

[ktzz]

Re: U3011 power fault?

okay from what i research even i get the bga memory, i will still need to reprogram it? or i can just buy a new one and just replace it?

[Agent24]

Re: U3011 power fault?

It looks like some glue or something on the memory, shouldn't cause a problem, in any case if the memory was faulty I think you would get picture or other issue all the time, not random power off after an hour.

Did you test capacitor ESR or just look at them? What brand are they?

[ktzz]

Re: U3011 power fault?

yeah i still get perfect image. oh okay. hmm i have not personally tested any capacitor yet. i only looked at them. and they seem okay. i think i will get them tested this weekend.

[Agent24]

Re: U3011 power fault?

Check the PSU board for bad solder joints too. Often in the inverter section where things run hot, parts can get bad solder joints over time.

[culmesm]

Re: U3011 power fault?

Probably u have problem whith lamp-lamps i do not know if it is whith lamp or led'stry to see error code

[ktzz]

Re: U3011 power fault?

Check the PSU board for bad solder joints too. Often in the inverter section where things run hot, parts can get bad solder joints over time.

Okay! shall have a more precise check later on!

Probably u have problem whith lamp-lamps i do not know if it is whith lamp or led'stry to see error code

hmmm!!! where can i test this thing???

[ktzz]

Re: U3011 power fault?

sorry for a noob question, in order to check all the capacitor i need to unsolder all the capacitor to check it? is there any way to check them without unsolder them all?


oh the chip i just confirmed it was burnt. but its bga memory surely it wont cause the problem of randomly power off right?

oh ya when there is no signal from the pc. the power button can remain orange throughout the night.

[Agent24]

Re: U3011 power fault?

Some ESR meters can test capacitors in-circuit, but you have to make sure there is nothing in parallel to affect the reading. If you want to be sure it's better to remove them all and test them out of circuit.

If the chip is literally burnt, I would expect you to have problems as soon as you turn the monitor on. If it works for 1 hour with a burnt chip, that is very strange. It should not work at all.

How do you know for sure the chip is burnt?

[ktzz]

Re: U3011 power fault?

okay. because there someone who happened to be dealing with all this chips. came by my home for a moment. so i can only get him to see this before he went away.

but what u said is quite true too for a bga memory.

can you intro me some esr meters that can test capacitors in-circuit? thanks! i have been looking into it. cant quite find it.

[Agent24]

Re: U3011 power fault?

The Blue ESR meter by Bob Parker can do in-circuit testing, but again, it depends on the circuit. It's easier to just remove them and test out of circuit, most of the time.

[ktzz]

Re: U3011 power fault?

thanks! im waiting for my esr meter to arrive. btw anyone got any guide to reflow the board?

[ktzz]

Re: U3011 power fault?

while waiting for the esr meter to arrive. i went ahead to replace most of the caps, although they look fine no bugle. but it was tilted. so i changed them. and resolder all the joint on the main logic board. and same thing happened. so agent24 was correct. it was not the bga memory problem. neither is the main logic board problem. i cleaned away the flux and stuff too.

i saw the caps on inverter board looks okay too!