Optiquest Qp

[maybenever]

This monitor is dead. Opened it up and saw 3 bloted caps. CapXon 470uf 25v, C546 KF 105c. I've got on hand 3 panasonic ECG 470uf 25v 85c, part # ECA-1Em471. I've also got 2 panasonic ECG 470uf 25v 105c, part # P12388-ND. My question is, can I use any of these for replacements. There's one cap sorta out in open, could I use the 85c cap there? The fuse checks OK.

[maybenever]

Re: Optiquest Qp

Excuse me, that's a Optiquest Q9, model YS11201.

[jetadm123]

Re: Optiquest Qp

They may work, but they will fail quickly because they are low temp and the wrong type of cap. You need something like Panasonic FM series

http://www.digikey.com/product-detai...2389-ND/613750

While you're at it, go ahead and replace all the other caps except for the large 450V one.

[selldoor]

Re: Optiquest Qp

As this is only a 19 inch screen? perhaps check a few other components first CCFLs Inverter transformers or use the cap[s you have then if it works upgrade them but it means doing the job twice.

[maybenever]

Re: Optiquest Qp

As this is only a 19 inch screen? perhaps check a few other components first CCFLs Inverter transformers or use the cap[s you have then if it works upgrade them but it means doing the job twice.

I don't know how to check inverter transformers. Could I get some tips?

[selldoor]

Re: Optiquest Qp

POWER OFF
Meter on Ohms 2000
Think your IT is like this one test S1> S2 and S3>S4 and post results.
I am off to bed so hopefully someone will tell you if they are ok before tomorrow.

[maybenever]

Re: Optiquest Qp

POWER OFF
Meter on Ohms 2000
Think your IT is like this one test S1> S2 and S3>S4 and post results.
I am off to bed so hopefully someone will tell you if they are ok before tomorrow.

Thanks, I'm off to watch a ballgame, I do some more checking tomorrow.

[selldoor]

Re: Optiquest Qp

Ok had another look at the caps - The 105degree ones you mention are Panasonic FMs - I would put them in next to the heatsinks and try one of the 85 degree ones out on its own. As I say if everything else works you can upgrade that one later.

[jetadm123]

Re: Optiquest Qp

Ok had another look at the caps - The 105degree ones you mention are Panasonic FMs - I would put them in next to the heatsinks and try one of the 85 degree ones out on its own. As I say if everything else works you can upgrade that one later.

I stand corrected. Looks like those two P12388-ND caps maybenever identified as ECG caps are indeed FM caps. Do as selldoor suggested and give it a try.

[maybenever]

Re: Optiquest Qp

I dug in my cap box and found another FM cap. Replaced those 3 caps and monitor powers up and works perfect. I kept it on for about 3 hours and no problems. I checked the inverter transformer, S1 to S2 = 992 ohms, S3 to S4 = 992 ohms. Should they be the same reading?

[maybenever]

Re: Optiquest Qp

I found this IT on LCDparts.net, and it is suppose to have 1k ohm, so mine is right there. I saved 4 of these monitors from the trash, 3 labeled no power, and 1 labeled dead. The 3 were dead, I opened one of them, it's the one I started this thread with that is now working fine. Connected the one labeled dead, it works great, for about an hour, then a thin red veritcal line appears on the right 1/3 of the screen, then 10 to 15 min. later, you can still see image on screen, but it has a reddish cast to everything. Opened it up, all caps look good (looks aren't everything, I know), but could the same failed caps on the 1st monitor be starting to fail causing this condition?

[selldoor]

Re: Optiquest Qp

Congratulations on the first fix - well done! must have missed seeing that post.
Yes the the two transformer readings should be within 3%

As I read it you have a few monitors the same so you have a few choices.

Hardest - Try and fix each one as an individual project.
Next take them all apart and mix and match - hard to control.
Easiest - take the next set and and just try one part swap at a time.

As it looks like this one has a panel board or panel or lvds cable problem
I would first clean the cable and re try.
Then if just the same unplug the working panel LVDS and backlights
and try the ones from the second set in the first.

[maybenever]

Re: Optiquest Qp

Thanks 'selldoor'
LVDS cables ???? Need a little more input here, I'm the beginner wanting to learn. You people are great to take the time for us dummies.

[selldoor]

Re: Optiquest Qp

LVDS cable is the one from the main board on connector cn6 it vanishes
under the silver tape. They sometimes come loose or loose contact and need a clean. Sometimes this causes lines on screen.
It may go direct to a connector on the panel or to another board that may be permanently attached to the screen.
Be very careful with the clips holding it - they get very brittle in the heat
need easing both sides at once.

Looking at it again its not going to reach - I think as a first step take out the power supply board and the main board from the non working machine and then take out the two boards from the working machine and
try them - you know they work so it will determine if it is a panel problem.

[maybenever]

Re: Optiquest Qp

Thanks again selldoor, with one working monitor, I can keep switching boards, pin down the problem. It'll be a little while, my wife threw me out of the kitchen, my shop (whick is where I want to be anyway) is not heated and it's getting pretty cold. I'll get em checked out and post back.

[maybenever]

Re: Optiquest Qp

I replaced the power board of the monitor that would develop vertical red line in the right 1/3 of the screen (after being on for an hour), with recaped board from working monitor. It didn't fix it, but it changed things. Now it has thin vertical red and blue lines in right 1/3, not the whole 1/3, but 3 or 4 thin lines. But now I only see them during the boot process and when screen saver comes on. After a few minutes of warm up, I don't see them at all. I can restart computer, and it's a clean image. Any ideas?

[selldoor]

Re: Optiquest Qp

Again i would suspect the lvds cable have you got another one you can try

[maybenever]

Re: Optiquest Qp

No, not at the moment. It could be my old shop computer I use for testing. It normally works OK, but it is an old Aopen (I think). Could be the graphic card in it. I fixed it for someone, but they wanted to play games on it. No way, it had windows 98 (not even 98SE). I changed the HD and found some old memory to add and got barely enough minimum to change OS to winXP. when you shut it down, you get the message "now safe to turn off computer". But it has worked with all other monitors.