Attempting to repair a Dell 2208WFPt monitor without a clue - Page 1
Forum section: electronics / repair

author: max.wwwang
author_rank: Frequent Contributor
timestamp: September 27, 2022, 05:34:12 am
content: Hi there, Help wanted.I have a Dell 2208WFPt monitor which is not working properly. It powers on and displays as it should but only for a few seconds then turns to black (looks like power-saving mode). The OSD menu button does not respond. I searched extensively online; it appears a common problem of this model on the Dell community website such as this:https://www.dell.com/community/Monitors/2208WFP-not-working/td-p/2826526.The Dell community website does not seem to give a solution except perhaps a replacement of the whole thing for some users whose complaint is the loudest. There are YouTube videos about replacing the bulging (visibly failed) capacitors which do not apply to my case (my caps are in perfect visual condition).I tested it on two computers with different cables (both from VGA and DVI, all converting to HDMI or DP).Wondering if anyone here happens to have experience of this and got a solution or a clue.

author: MikeK
author_rank: Super Contributor
timestamp: September 27, 2022, 01:07:48 pm
content: I recently fixed a trash-find 22" HP monitor. Similar problem...The display wouldn't stay on. It turned out to be bad solder joints at the CCFL bulbs. It's worth checking, as it doesn't require any special tools or skills. By the way, the menu button may not respond if there is no display input signal.

author: tunk
author_rank: Super Contributor
timestamp: September 27, 2022, 02:56:24 pm
content: Quote from: max.wwwang on September 27, 2022, 05:34:12 amEven if they look OK, they may still be bad.

author: wraper
author_rank: Unknown
timestamp: September 27, 2022, 03:11:55 pm
content: Most likely CCFL inverter going into protection and thus backlight shutting down. The most common reasons are bad electrolytic capacitors (usually bulge on the top but not always), bad CCFL transformer secondary winding or bad lamp.

author: wraper
author_rank: Unknown
timestamp: September 27, 2022, 03:20:54 pm
content: By the looks of PCB, CCFL transformer should have 2 secondary windings. Measure their resistance, it should be about 1 kOhm and almost identical for both windings. If winding measures open or winding resistances have significant difference then transformer is bad. EDIT: I think it's probably a wrong picture of power PCB on ebay or there are 2 versions of it. Another picture has 2 smaller transformers which should have a single secondary winding. In either case suggestion about measurement remains the same.

author: FIXITNOW2003
author_rank: Regular Contributor
timestamp: October 28, 2022, 06:21:29 am
content: not seen the 22" version but had a 2408WFP going into standby randomly needed to replace1x 150u/450V5x 470u/35V2x 47u/50V1x 1u/100V

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:11:33 am
content: Quote from: MikeK on September 27, 2022, 01:07:48 pmThanks. Have brought the monitor back together after the post and it has been collecting dust. Might get another crack on it before giving up - it's a bit hassle to crack the case open.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:14:00 am
content: Quote from: tunk on September 27, 2022, 02:56:24 pmThat's very true. But as an inexperienced repairer, I would exhaust all other tricks before replacing good-looking caps. Thanks.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:16:43 am
content: Quote from: wraper on September 27, 2022, 03:20:54 pmThanks. Will post a picture of the board if I got time to have another try.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:20:15 am
content: Quote from: NeddieTone on October 26, 2022, 07:15:20 amYes, indeed I have tried many things and have done extensive, if not exhaustive, search online without much useful information for this particular case. I don't believe Dell will help me as I'm not the original owner and it's very old. I've also considered the possibility of the cable issue so checked with a couple of different cables, known to be working on other monitors, but without luck. Thank you.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:25:49 am
content: Quote from: FIXITNOW2003 on October 28, 2022, 06:21:29 amThank you for sharing your experience. The problem of your 24" one sounds like different from my 22" - this one does not go into standbyrandomly, but rather in a predictable and repeatable way. That is, going into standby a few seconds after switched on. Before going off, it works like normal. Then never comes back. Despite of this difference, I will look more closely at the caps you mentioned if I got the chance to crack its case open again and give it another try.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:33:03 am
content: Actually I did take these photos then I opened it last time.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: December 17, 2022, 05:34:42 am
content: And this one.