NEC Multisync LCD 1550X knackered - Page 1
Forum section: electronics / repair

author: Messtechniker
author_rank: Frequent Contributor
timestamp: November 11, 2018, 08:44:29 am
content: My good old NEC Multisync LCD 1550X monitor has partly given up the ghost. See pics. It’s definitely the monitor since VNCing into it is fine and signals from both inputs (VGA from a PC and DVI from a scope) are affected. Has anyone seen this symptom for a quick fix? Of course I will take it apart as a last attempt before it goes into recycling.

author: mzacharias
author_rank: Frequent Contributor
timestamp: November 11, 2018, 01:06:08 pm
content: I would definitely start by checking the power supply caps. Very common problem on similar models.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: November 13, 2018, 08:45:26 am
content: The 5 electrolytics on the psu board are on my next order list now (all low ESR types) which will go out in a couple of weeks.Did only measure the 150 uF/400V cap:Measured as 127 uF (i.e. too low) and ESR was 0.5 Ohm which is OK (according to my list). At the time this LCD was manufactured (2004) all electrolytics used to be above their nominal value when new.Will have to wait and see.By the way: the service manual for this LCD is extremely detailed. Basically down to the last firmware bit everything is explained in enormous detail. Never seen anything like this for a LCD before.

author: james_s
author_rank: Super Contributor
timestamp: November 18, 2018, 08:18:28 pm
content: That's impressive, that was a high end monitor in its day though. I remember when LCD desktop monitors first came out, they were expensive and only the upper manager types had them at work.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: January 14, 2019, 02:23:15 pm
content: Well, not the capacitors this time.The PSU board was OK also after replacing the caps.Apparently the fault was on the video board.Unfortunately beyond repair.Its parts are now in the electronics waste bin after salvaging a few bits and pieces. So sad.Its bother (Multiscync LCD 1550V) is now in place for the rest of its life.Since it does not have a DVI port, I can now no longer display the screen of my HMO 1022 scope.Maybe a small monitor with a DVI and a VGA port will drop off a bench somewhere - hopefully some time soon.

author: wraper
author_rank: Unknown
timestamp: January 14, 2019, 02:58:36 pm
content: Did the same thing happen with OSD? IMO it looks like faulty LCD panel.

author: Armadillo
author_rank: Super Contributor
timestamp: January 14, 2019, 03:27:03 pm
content: Yeap, Faulty LCD Panel.

author: Bashstreet
author_rank: Frequent Contributor
timestamp: January 14, 2019, 05:39:30 pm
content: Any special reason to fix it ? getting new one with better specks second hand very cheap.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: January 14, 2019, 08:25:30 pm
content: Just for the heck of it. The use case, i.e. mucking around with non-activated W10does not even warrant the price for a used monitor. Had a spare one anyway.And also a further free spare for the spare is at hand.

author: james_s
author_rank: Super Contributor
timestamp: January 15, 2019, 08:54:07 pm
content: I fix a lot of stuff just because I can. There are certainly less useful ways to pass the time.