HP w2207h Intermittent Misbehavior

[Ed Hall]

What a beautiful monitor! (My first impression of it in use.) Of course that was after having it apart and before having troubles.

Background: A friend gave me this monitor because it was "acting up." I took it apart before even plugging it in. I found nothing of note in a pretty thorough visual inspection. So, I put it back together and fired it up. That's when I proclaimed what a great looking image it had. And, it worked all that night, leading me to believe it may have just needed internal attention.

However, the next day it didn't power up quite right. It would go through a cycle similar to:

Good image - 7 seconds
OSD Lockout message - 7 seconds
Blank screen - 7 seconds
Good image - 7 seconds
No Video message - 7 seconds
Monitor Status message - ~3 seconds
Good image - 7 seconds
Main Menu - 7 seconds
repeat in random fashion...

After doing this for a while, it stopped and started working fine. I tried leaving it ON continuously, even though the computer was off at night and it worked fine for several days without a single glitch.

Recently it has started in again, but only does a few repetitions before acting normal again.

While it is in its annoying cycling, all buttons including the Power are inhibited. Otherwise, everything works fine.

I'm wondering if a loose ground, or maybe a pullup (or, down) component is failing, but being intermittent, it's very difficult to troubleshoot.

I'm using the monitor as is, but when it fails, it is truly annoying. I haven't tried hitting anything with coolant, yet, although that's on the list the next time I take it apart.

As you can tell, I'm also not in a hurry to jump into it right now, either. But, that could change. In fact, while I was typing this post, the monitor performed two short, but still annoying, failure cycles, delaying my editing until it cleared up.

I thought I'd go ahead and post, in case anyone here has any insight before I do dig into the insides in depth. Maybe, it might even get to a point where it fails more frequently so it can be caught in the act.

Pictures can be provided next time I open it up, if there is any further interest. (Note: one more short failure cycle while I was constructing this paragraph...)

[blargg]

Re: HP w2207h Intermittent Misbehavior

I just got one of these with similar symptoms, and it was due to misbehaving microswitches in the button panel. Unplugging button panel stopped this madness. I found a thin film of something inside one of the microswitches which was causing ~30K resistance, enough to make it think that menu or the source select was being pressed. I cleaned this out of the microswitch and it seems to work now. I'd have replaced them but didn't want to try to find a microswitch of the same dimensions (I popped them open by cutting the tops off the melted plastic risers, and using some glue on the corners when reclosing it).

Another symptom before I repaired it was that one of the signal lines to the board didn't have the normal 1.8V, rather something lower like 1.4V. It was hard to confirm the resistance it was putting across because it was very intermittent, only appearing sometimes with the meter.

Another tip when opening monitor: don't use the suggest approach of putting something between the LCD and bezel, because it's too easy to scratch. I put something similar to a wide flathead screwdriver into the outside groove of the bezel and used it as a lever to try to pull the bezel away from the case. At the same time, I used my fingers to press the inside edge of the bezel around the LCD towards the outside. This outside push unhooks the catches while the screwdriver pulls them apart. I used a wider metal object (PCI slot cover from a desktop PC) to do the prying and a hand towel to pad the silver edge of the monitor so it didn't get nicked while I was prying. I started the process in the middle of a side edge rather than near a corner where it's harder. I'll admit that my fingers hurt a little afterwards due to the high force needed to uncatch the hooks. I had it open in a few minutes without any risk of damage to the LCD (last time I opened one of these I scratched the LCD near the edge, even though I was using only a thick plastic card to pry it open, nothing metal).

[Ed Hall]

Re: HP w2207h Intermittent Misbehavior

Thanks blargg,

I have been powering the monitor via an external switch for some time now and it has been running fine without any more troubles. If it starts acting up again, I'll dig into the suggestions you made. Thanks for the opening info. I actually didn't have too much trouble when I opened it originally, although my fingers also became a bit sensitive. I don't remember where I found the opening info back then.

[Ed Hall]

Re: HP w2207h Intermittent Misbehavior - Follow-up

Several months have gone by without any trouble, but just a couple days ago the volume menu appeared and stayed. No buttons would do anything once this happened. Per blargg's info, I popped the monitor apart, removed the switch board and reassembled it. Everything is working fine and since I'm not concerned with any of the button functions, at least for now, I'm using it happily as is.

I did examine the board and switches, but can't find anything wrong. All the switches show 0/>1M ohms and work as designed. I actually have some microswitches somewhere that may might work on this board. If I gather enough interest, I'll find them and see what happens if I swap them all out. I probably won't take blargg's approach of repairing the switches (although I often do things like that), unless I need the use of the buttons.

[Davi.p]

Re: HP w2207h Intermittent Misbehavior

The button trouble suggestion is the more easy and possible for this type of oddities, for me..