@yaoabrahambrou first you should verify that you have no image on all inputs. If it remains dark, unplug it and push the power button for about one minute, then plug it back in. See if that resets your TV.

If it remains dark, use a flashlight and shine it at an angle against the screen. Turn the TV to a channel where you can hear sound and do that in a darkened room. See if you can make out shadows or shapes. If you do, then it is your backlight that has failed. If you do not see anything, unplug your set and remove the back. Then visually check the boards for any obvious damage like domed or leaking capacitors. Check all the wiring and unplug the wires and plug them back in to make sure they are properly seated. Post some images of all of your boards with your question. Use this guide Adding images to an existing question for that so we can see what you see. It is possible that this is either a power board issue or a T-con board issue.

TCL is known for bad backlight LED's. That is my first suspect.

Translation

@yaoabrahambrou Vous devez d'abord vérifier que vous n'avez pas d'image sur toutes les entrées. Si l'image reste sombre, débranchez le téléviseur et appuyez sur le bouton d'alimentation pendant environ une minute, puis rebranchez-le. Voyez si cela réinitialise votre téléviseur.

Si l'obscurité persiste, utilisez une lampe de poche et éclairez l'écran en l'inclinant. Réglez le téléviseur sur une chaîne où vous pouvez entendre du son et faites-le dans une pièce sombre. Voyez si vous pouvez distinguer des ombres ou des formes. Si c'est le cas, c'est le rétroéclairage qui est défectueux. Si vous ne voyez rien, débranchez votre appareil et retirez le dos. Vérifiez ensuite visuellement que les cartes ne présentent pas de dommages évidents, tels que des condensateurs bombés ou qui fuient. Vérifiez tout le câblage, débranchez les fils et rebranchez-les pour vous assurer qu'ils sont bien en place. Postez des images de toutes vos cartes avec votre question. Utilisez ce guide Adding images to an existing question pour que nous puissions voir ce que vous voyez. Il est possible qu'il s'agisse d'un problème de carte d'alimentation ou de carte T-con.

TCL est connu pour ses mauvaises LED de rétroéclairage. C'est mon premier soupçon.

@xavierelgenio working on printers is always a pain. Luckily there is a service manual, but I only have an English version. The paper feed roller is described on page 3-135 of this manual

Hope this helps with your repair.

Translation

@xavierelgenio travailler sur des imprimantes est toujours une galère. Heureusement, il existe un manuel d'entretien, mais je n'ai que la version anglaise. Le rouleau d'alimentation du papier est décrit à la page 3-135 de ce manuel Brother MFC J6930dw

J'espère que cela t'aidera dans ta réparation.

OEM stands for Original Equipment Manufacturer and is typically used to indicate that the parts are from the same original manufacturer(s) as the brand—in this case Apple—you know and trust. Apple doesn't actually make the screens and the display assembly is from several companies.

I'll let iFixit comment directly on their OEM policy, but generally, yes, it means it's same model/specs/manufacturer(s) as an original iPhone.

If you have the gasket all I do is wet a small piece of paper towel with WD40 and wipe it down to lube it a bit (only needs a very little) then I place the gasket on the display so I can identify the center as I want to start there. Pressing the gasket in with my finger and doing a small part on each side as well as checking to make sure I haven’t stretched it as I go. Then the fun part cleaning the screen! As the WD40 will need to be cleaned off without making streaks. After wiping the gasket with a dry paper towel using different areas of the towel going along it I then go again with 90% reagent grade isopropyl alcohol a few times with just damp (not wet) paper towel. Then lastly I go from the center of the display outwards with a fresh towel slightly damp making sure not to drag across with a towel surface that already has WD40 on it. Then I use a good micro cloth with a screen cleaner sprayed on the cloth in the same way from the center outwards.

How to change touche screen

@livfe if the battery has been discharged below it's charging threshold, it will not take a charge. That is where the controller IC will lock the battery down. You adventurous? You can try and bring up the charge on the battery by attaching something like a bench top power supply (positive to positive and negative to negative) and apply a trickle charge of a few volts and low amps to the battery directly. Sometimes this will "kickstart" the battery.

What MBA model is this?

@wozniattack - Ah! So it’s a pad using the bottom plate to dissipate the heat, that makes sense.

To verify the needed thickness you could use a pile of business cards placed on the bottom case where the pad would go stacking them up to gage what’s needed. Once you have set the thickness you can get what you need. There is gaping thermal paste Apple moved to it to save some effort applying the pads on the VRAMs. Not a lover of this TIM but that’s another possibility.