Chosen Solution
When I open my laptop’s lid beyond a point (say approx 90 degrees), the display turns off while the programs are still running. This problem initially started at more than 120 degrees (which was not affecting me much). But it deteriorated gradually to around 90 degrees now. The problem is consistent (happens at any time of the day and usage). Currently using the laptop by not opening it beyond 90 degrees and adjusting my seat. No other problems exist. Works fine if I use it this way. But it’s getting frustrating and soon it will deteriorate further to <45 degrees making it unusable. It’s definitely a HARDWARE issue related to the screen. I live in India. This is a Lenovo B490 laptop. Can somebody please point out which part is malfunctioning and what to do about it?
Hi @bachuz , Check with a torch, held at an angle close to the screen whether you can still detect an image at all when the display “turns off”. If it is there it will very faint, so you might have to try this in a darkened room to see if you can detect any images at all. It may be that only the LCD backlighting is missing and not the video signal. If you cannot detect anything at all or even if you can detect an image, I suspect that it may be that the video cable is the problem (where it passes through, near the hinge, from the motherboard in the lower case to the LCD screen in the lid). Here is a link to the service manual for your laptop. Scroll to p.73 to view the necessary pre-requisite steps and then the procedure to remove the LCD cable from the display unit. Here is a link to just one supplier of the replacement part. It is not a recommendation to use them. It is shown to give an idea of the cost of the part. There are others online who may suit you better. Just search for Lenovo B490 LCD cable part for results. Hopefully this is of some help
