JVC LT-40N940U LED TV Service Manual - Page 1
Forum section: electronics / repair

author: CHexclaim
author_rank: Regular Contributor
timestamp: December 15, 2017, 02:15:58 am
content: Hello everyone.I 've been looking for the service manual for a JVC led TV model LT-40N940U for a while now with no luck. Can anybody help.More specifically the problem is that anything when a source from HDMI is selected the image is bigger than the screen so it gets cropped all around. It is not critical as most of the time the content on the borders is not crucial but sometimes captions and titles are cropped.Thank you, CH

author: EHT
author_rank: Frequent Contributor
timestamp: December 15, 2017, 03:02:26 pm
content: That sounds like a mode setting. There may be a zoom/widescreen setting which you adjust depending on the source.You could try connecting HDMI to a computer and checking the display modes reported to the graphics card using EDID. See if that displays correctly or not as well.

author: wraper
author_rank: Unknown
timestamp: December 15, 2017, 03:04:50 pm
content: It rather seems that you need user manual, not service manual.

author: CHexclaim
author_rank: Regular Contributor
timestamp: December 15, 2017, 03:58:34 pm
content: Thank you for the replies.This is a quite low end TV, sold on developing countries like here in Uruguay.Everything I plug into HDMI is cropped, not the DTV tuner inside the TV which works great.There are no options in user menus, they are very basic.If I connect my PC via HDMI it is also cropped but in the PC I have a zoom thing that I can make the screen smaller and work around the issue.So, my last resort is that there should be something in the service menu, as I saw in other service menues of other JVC TVs.What I need most is the key combination to enter the service menu.Thanks.CH!

author: Armadillo
author_rank: Super Contributor
timestamp: December 15, 2017, 04:18:51 pm
content: Have you set your TV aspect ratio to "FULL".I am not sure but you can try this to enter service mode.Before entering the SERVICE MODE, confirm that the setting of TV/CATV switch of the REMOTE CONTROL UNIT is at the "TV" side and the setting of VCR/DVD switch is atthe "VCR" side. If the switches have not been properly set, you cannot enter the SERVICE MODE.(1) Set to 0 minutes using the [SLEEP TIMER] key.(2) Press the [VIDEO STATUS] key and  key simultaneously, then enter the SERVICE MODE.Above at your own risk, don't come blame me for your adjustment.

author: wraper
author_rank: Unknown
timestamp: December 15, 2017, 04:37:29 pm
content: Quote from: CHexclaim on December 15, 2017, 03:58:34 pmI don't think there are any LCD TVs without aspect ratio setting. If you cannot find it in the menu, check if remote has such button.

author: CHexclaim
author_rank: Regular Contributor
timestamp: December 15, 2017, 05:15:58 pm
content: Thanks,Armadillo's reply does not aply as the remote on my TV is much simpler and does not have those keys.I am attaching a photo of the remote...

author: Armadillo
author_rank: Super Contributor
timestamp: December 15, 2017, 05:20:57 pm
content: Then find inside the "MENU" for settings and find "aspect" setting.

author: wraper
author_rank: Unknown
timestamp: December 15, 2017, 05:30:56 pm
content: Quote from: Armadillo on December 15, 2017, 05:20:57 pmAnd "aspect" likely will be within "display (settings)" submenu or something like this.

author: CHexclaim
author_rank: Regular Contributor
timestamp: December 15, 2017, 05:32:58 pm
content: FIXED, I guess.Well, this thing is buggy.I found Aspect in the Picture menu but it was greyed out for HDMI input.I selected the TV tuner and Aspect was accesible with some options I don't recall.I went back to HDMI and sudenlly the Aspect option was now accesible. It has the following options: 4:3, 16:9 (wich is the one selected), zoom 1 which makes the image even bigger, zoom 2 which makes the image huge, and PC mode.In PC Mode the image seems to fit perfect on the screen. I will do further testing and let you know if I still have problems, but it seems fixed.Thank you people.Anyhow if someone knows how to get into the service menu, please tell.CH!

author: Mostafa.samirpo@gmail.com
author_rank: Newbie
timestamp: October 16, 2018, 02:36:25 pm
content: I am looking for service menu jvc lt40n640Please support