Iiyama prolite 1900s dead

[bluebear]

Re: Iiyama prolite 1900s dead

Sometimes the no signal sign is small or moves around and easily missed without a backlight.

Using a computer for display, you can look for your favorite desktop display/background.

It also helps if you are in a dark room to verify.

Yes you are right, it is somewhat small and moves around.
I will check it tomorrow. However, since I can´t switch it off I have a gut feeling that the logic-board is fried, most likely the logic chip tsum056J-LF. Or some other part. Since something clearly was burning when it died. Haven't found a fuse on the logic board, nor could I find a datasheet for the logic-chip. Ah, mates its late here. I will post tomorrow.

[retiredcaps]

Re: Iiyama prolite 1900s dead

However, since I can´t switch it off I have a gut feeling that the logic-board is fried, most likely the logic chip tsum056J-LF.

I agree that it looks more and more like the logic board, but let's rule out all the possibilities.

[bluebear]

Re: Iiyama prolite 1900s dead

Tried with dark room and pc and flashlight. The screen is black, nothing on it except black and only black.

I have studied the logic-board closley and found a potential malfuntion.
A small smd part marked L104 near a 10uF condensator looks like it is fried and something has leaked out on the pcb. I´m not shure what it is, but its not a resistor.
Anyways found 3 more of the same on the pcb marked L105, L106 and L103. Each one near a 10uF condensator.

I ohm measured each and got this result.
L104 (the burnt, leaked part) 600Ohm
L103, L105 and L106 ,measured 80Ohm.

I have a attached a picture where L104 is marked with red circle, the rest marked with blue circle.
I´m sorry the picture is a bit out of focus, but you can actually see the leakage.

So what is it, how do I find out? what do I replace it with?

[PlainBill]

Re: Iiyama prolite 1900s dead

Tried with dark room and pc and flashlight. The screen is black, nothing on it except black and only black.

I have studied the logic-board closley and found a potential malfuntion.
A small smd part marked L104 near a 10uF kondensator looks like it is fried and something has leaked out on the pcb. I´m not shure what it is, but its not a resistor.
Anyways found 3 more of the same on the pcb marked L105, L106 and L103. Each one near a 10uF condensator.

I ohm measured each and got this result.
L104 (the burnt, leaked part) 600Ohm
L103, L105 and L106 ,measured 80Ohm.

I have a attached a picture where L104 is marked with red circle, the rest marked with blue circle.
I´m sorry the picture is a bit out of focus, but you can actually see the leakage.

So what is it, how do I find out? what do I replace it with?

L indicates an inductor. I'm a little surprised that the others measure 80 ohms; that seems very high to me. Those parts all are in power supply lines. Doing a little creative research, a possible replacement part would be Laird Technologies HZ0805E601R. Checking a data sheet, it has a DC resistance of .3 ohms.

I would check L104 out with power applied to the board. Measure the voltage from ground to each side of the part.

PlainBill

[retiredcaps]

Re: Iiyama prolite 1900s dead

Tried with dark room and pc and flashlight. The screen is black, nothing on it except black and only black.

Okay.

A small smd part marked L104 near a 10uF condensator looks like it is fried and something has leaked out on the pcb.

I ohm measured each and got this result.
L104 (the burnt, leaked part) 600Ohm
L103, L105 and L106 ,measured 80Ohm.

That "goop" could be flux residue left over from the factory process or it could be leakage from the capacitor's bung (bottom)? Caps can leak from the bottom just as easily as the top. See "bushytail" pics at

https://www.badcaps.net/forum/showthread.php?t=424

Odd, most inductors (L) that I have measured read 0.3 ohms. To have 80 ohms is quite high.

Put your multimeter on 200 ohms (if manual). Now touch the two probes of your multimeter together. What reading do you get?

[bluebear]

Re: Iiyama prolite 1900s dead

Hi and thanks for your reply PlainBill.

Measured voltage as you suggested.
On the side facing the VGA/DVI sockets I had 3.347 V.
On the opposite side against the big IC chip it measured 29.7mV.

I measured the two remaining L10* with 10uF capacitor and they both had 3.340V on both sides.

Maybe we are on to something here.

[bluebear]

Re: Iiyama prolite 1900s dead

Put your multimeter on 200 ohms (if manual). Now touch the two probes of your multimeter together. What reading do you get?

Measuring the cables gives a 2,7 Ohm reading.

[retiredcaps]

Re: Iiyama prolite 1900s dead

Measuring the cables gives a 2,7 Ohm reading.

Wow, probably time for a new multimeter??? My multimeter reads 0.3 ohms doing the same test.

Maybe try using a fresh battery(ies) and try cleaning your probes.

[bluebear]

Re: Iiyama prolite 1900s dead

Wow, probably time for a new multimeter??? My multimeter reads 0.3 ohms doing the same test.

Maybe try using a fresh battery(ies) and try cleaning your probes.

Hehe, silly me. It has been beeping relentlessly these last days and shutting down. I don´t have a new battery so i will fix it tomorrow.

[PlainBill]

Re: Iiyama prolite 1900s dead

Hi and thanks for your reply PlainBill.

Measured voltage as you suggested.
On the side facing the VGA/DVI sockets I had 3.347 V.
On the opposite side against the big IC chip it measured 29.7mV.

I measured the two remaining L10* with 10uF capacitor and they both had 3.340V on both sides.

Maybe we are on to something here.

Definitely.

I agree with retiredcaps comments about possible leakage from the adjacent cap. I'd replace both cap and inductor.

NOTE!!! The part I mentioned was cribbed from the parts list of another monitor. Check the dimensions of the existing inductors and order something with the proper physical characteristics.

PlainBill

[bluebear]

Re: Iiyama prolite 1900s dead

My multimeter reads 0.3 ohms doing the same test.

Yes, i now have 0.5 Ohm.

Update:
I scavanged a similar smd inductor and replaced L104. No picture and the green diode on the front (on/off light) is glowing with a faint light, and you could hint a touch of orange in it. I measured voltage on L104 and have 3.347 on both sides. I then noticed that the large logic chip in the middle of the pcb was warm. Unfortunately when I touched it i burned my finger, it was really hot. It is probably shorted.

So my original thought that the logic board was fried holds true. I think we can close this thread.

A thank you goes to retiredcaps, jetadm123 and PlainBill for suggestions and help.

I will start a new thread on my broken Benq