Dell se2419h monitor - Page 1
Forum section: electronics / repair

author: MarkBob
author_rank: Contributor
timestamp: May 24, 2021, 09:11:50 am
content: HiI have 2 of te above mentioned monitors with the same fault.The power button is lit but when pressing to switch on no logo nor screen come to life .Tested all electro -caps all seem fine.No power to backlights.Please i am stumped

author: RayRay
author_rank: Frequent Contributor
timestamp: May 24, 2021, 12:46:46 pm
content: How exactly did you test the capacitors? Also, Do any of em have a bulged (non-flat) top? Have you checked the fuses & diodes?

author: MarkBob
author_rank: Contributor
timestamp: May 24, 2021, 01:48:02 pm
content: HiRemoved all caps and tested caps on both psu s replacing 1 board with new caps ,other board with tested and checked all the diodes on both. I get standby power and 24 v on 2 pins and no other voltage. The backlight output has 0v .On the video board i replaced 2 caps still no change.

author: RayRay
author_rank: Frequent Contributor
timestamp: May 24, 2021, 01:54:15 pm
content: Could you provide pictures of the board (from both sides)?

author: perieanuo
author_rank: Frequent Contributor
timestamp: May 24, 2021, 04:17:42 pm
content: Quote from: MarkBob on May 24, 2021, 01:48:02 pmyep, you got a problem: no 5V or 3.3V presentusually you have 5V standby voltage that powers some micro monitoring the buttons, to put it simpleno 5V, no micro workingeither you missed those 5V either the 5V regulator is dead, gotta dig this standby voltage, it's a classic even for pc supplies, tv's and other equipment.try to trace that missing voltage, maybe on 5V rail you have a short (any component hot?)regards,pierre

author: MarkBob
author_rank: Contributor
timestamp: May 25, 2021, 10:18:37 am
content: Here are the pics

author: MarkBob
author_rank: Contributor
timestamp: May 25, 2021, 10:47:20 am
content: Does anyone have a schematic diagram as i am unable to source one

author: RayRay
author_rank: Frequent Contributor
timestamp: May 25, 2021, 01:18:58 pm
content: Couldn't find a service manual for this particualr model. Anyhow, I assume you've only tested the diodes on the brown side? Did you test em in both forward & reverse bias? You're not suppose to get a reading in reverse bias FYI. Also, what about testing the resistors & ceramic capacitors? Try to wiggle the white connectors a bit (to see if they're loose), they might require a reflow. And just so you know, this board is available from multiple sellers (at affordable prices) on ebay:https://www.ebay.com/itm/114663964073https://www.ebay.com/itm/133602634051So if nothing goes, you have the option of just replacing em.

author: MarkBob
author_rank: Contributor
timestamp: May 25, 2021, 02:01:23 pm
content: HiThanks so much i shall test on the other side .......i just find it strange that both monitors have the same fault

author: RayRay
author_rank: Frequent Contributor
timestamp: May 25, 2021, 02:16:33 pm
content: You're very welcome. And yes, it's indeed quite strange, which brings me to the following question: Were you using each monitor with a different computer, or both with the same one (in a dual monitor setup)? If the 2nd, it's possible the problem is with your computer (and not the monitors). Just putting that possibility out there.

author: MarkBob
author_rank: Contributor
timestamp: May 25, 2021, 03:06:12 pm
content: HiDifferent desktops but in the same office .I shall check the resistors as they are fuseable arent they. All the diodes i checked in rev bios and they checked out fine.Ordering via ebay and shipping is so costly to where i am its probably cheaper to go the new Route which unfortunately i ust cant doThanks so much in advanceRay- Ray

author: perieanuo
author_rank: Frequent Contributor
timestamp: May 25, 2021, 03:15:10 pm
content: your smps creates 2 voltages: one that goes to the connector with wires and a second one (D633?) which powers the smd chip with soic16 caseyou measured the second one? that one should be 5V for standby control

author: MarkBob
author_rank: Contributor
timestamp: May 26, 2021, 07:20:40 am
content: I shall check that out .....Thanks so much

author: MarkBob
author_rank: Contributor
timestamp: May 26, 2021, 08:25:51 am
content: Hi perieanuoOn the second voltage i get 7.5vOn the back of the voltage regulator i get 7.2vI have no clue as to why the voltage is soi guess i will have to find a recycled set of boards

author: perieanuo
author_rank: Frequent Contributor
timestamp: May 26, 2021, 11:54:45 am
content: the soic 8 chip code is?i doubt 7.5V is ok for voltage regulator chip that powers the soic8 ic.it's obvious the 7v5 is the source voltage for the 5V (or 3v3 who knows..., that's why i ask about the soic8)well, it's already june, i give up this one