ASUS VH222 has no image

[ucdzombie]

Re: ASUS VH222 has no image

Not easy, I never bother fixing bad tab bonding on monitor. I use thermal transfer pad, you can use rubber pad to press down on the tab. The bad part is that you have to take the panel apart again and just do not cause more or new damage.
https://www.badcaps.net/forum/showthread.php?t=25371

OK I think I fixed the problem using your solution. The monitor appears to be stable after many hours of normal usage. I placed rubber pads on top of the tabs and they're now stablized. Thank you all!!!!

[ucdzombie]

Re: ASUS VH222 has no image

Not easy, I never bother fixing bad tab bonding on monitor. I use thermal transfer pad, you can use rubber pad to press down on the tab. The bad part is that you have to take the panel apart again and just do not cause more or new damage.
https://www.badcaps.net/forum/showthread.php?t=25371

This is the status of my screen right now:





I think the top tabs are loose. The other night I was able to let it run without problem for an hour, because I remember repositioning the TCON board (which is connected to the taps). Do you see anything unusual? The third picture shows some glue on the side tap.

[budm]

Re: ASUS VH222 has no image

Not easy, I never bother fixing bad tab bonding on monitor. I use thermal transfer pad, you can use rubber pad to press down on the tab. The bad part is that you have to take the panel apart again and just do not cause more or new damage.
https://www.badcaps.net/forum/showthread.php?t=25371

[ucdzombie]

Re: ASUS VH222 has no image

"When I was disassembling the monitor previously, at one point I opened the screen assembly. So maybe I ripped some cables there?" OK, that is one important info, it sound like the bonding between the LCD glass panel and the long PCB has loose tab bonding. The connections can expand from the heat of the lamps, they do get pretty hot.

I remember some of the tabs came loose when I opened it. But I didn't know what to do nor did I think it was important. I'm such an idiot! So how should I fix the loose bonding? Double sided tape?

[budm]

Re: ASUS VH222 has no image

"When I was disassembling the monitor previously, at one point I opened the screen assembly. So maybe I ripped some cables there?" OK, that is one important info, it sound like the bonding between the LCD glass panel and the long PCB has loose tab bonding. The connections can expand from the heat of the lamps, they do get pretty hot.

[Davi.p]

Re: ASUS VH222 has no image

Primary negative and secondary ground can have a different voltage, so that potential could have damaged the mainboard or also the tcon bd but you will never get on top of this i think, it is much probably damaged one of the bigger chips, from the few i know... you can if you want try to find a new main bd or leave it so if it don't hurt too much..

[ucdzombie]

Re: ASUS VH222 has no image

I would try cooling the logic board first, then the T-CON board, if the problem is on the T-CON, then that will be real difficult to repair.

OK I didn't try to cool it. However, I found something new. It has to do with movement. I tried tapping the side of the monitor and when I tap it, the lines are gone.

When I was disassembling the monitor previously, at one point I opened the screen assembly. So maybe I ripped some cables there?

[budm]

Re: ASUS VH222 has no image

I would try cooling the logic board first, then the T-CON board, if the problem is on the T-CON, then that will be real difficult to repair.

[ucdzombie]

Re: ASUS VH222 has no image

That heatsink has line voltage on it, you probably shorted to safety ground. Need to see which component is bad first.

Also, you mean try cooling the TCON board or the PSU?

You said to find the bad component. Is there any standard procedure I can follow to test? I can't even find the fuse on the PSU. Sorry I'm such a noob.

And lastly, if I don't fix this problem, will it hurt the monitor? I mean it's not very noticeable at all.

[budm]

Re: ASUS VH222 has no image

That heatsink has line voltage on it, you probably shorted to safety ground. Need to see which component is bad first.

[ucdzombie]

Re: ASUS VH222 has no image

You may try cooling the board with canned air using it upside down for cooling to see if the problem will disappear since the problem seems to happen after warm up.

OK will do. If this is the problem, will there be a long term fix solution? Like installing a heat sink??

[ucdzombie]

Re: ASUS VH222 has no image

We are sure exactly where the spark happened, can you show us? But since you did get good pictures for an hour, then the spark may not be related to the problem.

You can't see the burn mark in the picture because it's taken before I assembled it.

[budm]

Re: ASUS VH222 has no image

You may try cooling the board with canned air using it upside down for cooling to see if the problem will disappear since the problem seems to happen after warm up.

[ucdzombie]

Re: ASUS VH222 has no image

have you seen if each cable is isolated well now? try to locate where the spark gone from.. i think now your monitor is more of there that of here..

If you look at my first post with the picture, it's the big metal bar on the right. What happened was that I accidentally placed some wires (wrapped) between the metal bar and the protective metal shell. When I plugged it in, it made a spark right there because I saw some burn mark on the wire wrapping and the metal bar, as well as the metal shell. So maybe the wire wrapping conducted electricity and it shorted something? But the monitor worked fine afterward for 15 minutes.

[budm]

Re: ASUS VH222 has no image

We are sure exactly where the spark happened, can you show us? But since you did get good pictures for an hour, then the spark may not be related to the problem.

[ucdzombie]

Re: ASUS VH222 has no image

Logic to T-CON. Also make sure all the board mounting screws are tight since it uses the chassis as the ground.

OK last night I re-seat the LVDS cable and secured the board (it was loose before). And it worked nicely without any weird images for a hour. I left the monitor on standby and today I turned it on, the phenomenon came back after 10 minutes. It's hard to describe. The horizontal white lines are very very small (almost not visible). The area starts with the top of the monitor, and then the entire monitor starts to have white lines.

Do you think the spark I made yesterday from the accident could have burned something? How comes it's so random?

[Davi.p]

Re: ASUS VH222 has no image

have you seen if each cable is isolated well now? try to locate where the spark gone from.. i think now your monitor is more of there that of here..

[budm]

Re: ASUS VH222 has no image

Logic to T-CON. Also make sure all the board mounting screws are tight since it uses the chassis as the ground.

[ucdzombie]

Re: ASUS VH222 has no image

Did you already try re-seating the LVDS cable?

OK will try this tomorrow. But I think it's pretty tight already. Are you talking about the one that goes from the PSU to the logicboard? Or the the one from the logicboard to the TCON?

Also, this symptoms goes away if I unplug the monitor for more than 15 minutes.

One last thing, when I was installing it today, there was an accident. The cable from the switch panel was placed between one of the heatsinks (I don't know what's it's called. But it's the big metal bar) and the metal shell. When I plugged in the monitor for the first time, it made a spark. I thought screwed up the monitor. Later I fixed the cable, and it turned on fine. And then this symptom appears after 15 minutes or so.

[budm]

Re: ASUS VH222 has no image

Did you already try re-seating the LVDS cable?