crwdns2933423:0crwdne2933423:0

Anyone know where to get the backlight chip?

ASUS FX504GD-BB71-CB

One night I get home from work and I try to turn on my laptop and it seems like nothings happening, I plug it to my monitor and it looks like that is working but the main screen doesn't work, I end up replacing the LED panel and nothing... so the laptop itself is working and I switched video cables too and nothing so... it looks like the small chip or whatever its called that controls the backlight has died or something...

so I was wondering if anyone would know where I could buy it? it's a small chip next to the video cable connector on the motherboard... idk what they're called.

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crwdns2947414:01crwdne2947414:0

We'll need one of two things to help in this case (or both). Can you post a picture of what your board looks like? You can edit it right in to your original question.

The other thing that might help is if there's a model number or part number for the board.It's usually labelled pretty obviously.

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crwdns2934051:0crwdne2934051:0

Hi @downtoclown777,

If it has only two connection points, in this instance more likely it is a fuse and not an IC (chip). Does it look damaged or heat stressed?

Disconnect the battery from the motherboard (unplug it) and use an Ohmmeter to measure the component for continuity to see if it is OK or not i.e. 0.00 Ohms and not OL or infinite Ohms..

If you don't have a DMM (digital multimeter) post an image of the "chip" in your question. Here's how to do this on ifixit Adding images to an existing question.

Another way to test if it is a backlight problem or something else is with the laptop turned on try shining a flashlight at an angle close to the laptop screen and check if you can detect any images on the screen at all.

They will be very faint if they are there to be seen so trying this in a darkened room may help.

If you can see images then there's a backlight problem with the display.

Since you have changed LCD panel, check if the F1 fuse on the motherboard is OK and not blown - see above

This is the fuse that supplies power to the backlights in the display.

Below is an image taken from the schematics showing the fuse and where it connects to pins 32-34 of the EDP cable connector on the motherboard.

There's always backlight power being supplied to the display when the laptop is turned on. It is a signal sent on the EC_DISPON lead (pin 22) that tells the display to either turn the backlights on or off. The power is not turned off on the motherboard

If the fuse is blown search online for a 0467002.NRHF/2A/32V_0603 fuse to find suppliers that suit you best. Purchase two or three just in case, as usually fuses don't fail for no reason so if the replacement also fails shortly afterwards the reason will have to be found.

If you can't see any images, (or if the fuse blows again) the schematics will help to find out what's happening.

Block Image

(click on image)

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thank you so much sorry for the delay on replying, long story short i've replaced the video cable and the screen and theres no video out, but works through HDMI I think I flashed a flashlight on the screen and confirmed there is video but too low to see anything thus confirming the backlight chip fuse thing that usually blows out.

do you think it could of blown out due to using a different screen than originally came with it? [i have a lower refresh rate on it because the original is high refresh rate and a lot more expensive to replace than the one I had sitting around that fit properly]

thank you I do wanna try replacing that fuse and see if that takes care of it meanwhile so I can use it like a normal laptop lol

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@downtoclown777

You would have to search for both of the "(insert make and model number of the LCD panel) datasheet" (not the laptop maker's part number but whoever manufactured the LCD panel) which is usually located on the back of the panel itself to check the eDP cable pinout connections for the screen to see if the same pins are used for the same function in both LCD panels.

If they aren't then that could be why it doesn't work

If they are and if the fuse has blown, did you disconnect the battery from the motherboard before replacing the original LCD panel?

If not leaving it connected whilst replacing the screen may have been the reason but the only way to know is to replace the fuse and check if the screen now works OK

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

so I always had the battery off, I added the other screen and it worked fine for a few months, one day I just got home and got no video and determined it was either the cable or the panel or the fuse and exhausted the options I had and thus the fuse remained.

so in short it worked with the replacement screen I had handy for various months, just went out one day by itself outta the blue for some reason. [always do switch display panels with the battery off to avoid blowing the fuse yeah.]

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

@downtoclown777

If it is the fuse that has blown, check what it looks like physically.

If it looks normal i.e. no obvious signs of heat stress or damage then it could have simply fatigued - failed internally due to possibly continually operating at the upper end of its rating - unusual but it can happen sometimes with fuses.

If it is obviously burnt out, this indicates excess current flow through the fuse so it may be a problem in the display or even the eDP cable

You won't really know until you replace it.

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