Question LCD Backlight issue/BIOS question for ASUS TP500LN Laptop

[Lodmot]

Hey guys, got a serious advanced/involved situation to ask you about.

To make a long story short, I was trying to upgrade my girlfriend's laptop, which is an ASUS TP500LN. During the process, i ended up breaking the connector on the motherboard for the battery.

Taking responsibility for my clumsiness, i bought her a new motherboard on eBay for $200. I received the motherboard, and it indeed was the same model motherboard she had before (E162264). However, the LCD screen's backlight does NOT work on this new board (but there is a video signal which can be seen faintly if you hold a light up to the screen). I already verified that the LCD wiring is good and still works in the old board. Everything else is functioning normally (e.g. sound, USB, WiFi).

Upon further investigation, i discovered that the TP500LN bios actually refuses to flash on this motherboard, because the system thinks it is a "TP500LNG".

So the two things Im wondering are:

1. If the two motherboards are the same exact model number (E162264), shouldnt i be able to successfully flash the "non-matching" TP500LN bios by using a different utility that allows me to flash any bios file i want without restriction?
2. Given that the bios on the new motherboard is apparently different from that of what's on ASUS's official website (albeit only SLIGHTLY different), could that be contributing to the problem with the LCD backlight? And if so, could flashing potentially fix the problem?

Any help with this problem is greatly appreciated. Thanks!

 

[Lutfij]

When sourcing boards for a laptop, you need to make sure you're working with the exact same model. If you can't flash the BIOS on the board, then you need to quit at that stage, since a bad BIOS or a failed/half baked update can and will cause you to end up with a bricked board, meaning another 200USD out of your wallet.

I'm fairly certain that the board you have might be an older version that what was in your laptop and perhaps that's what's conflicting with the display. Yes, BIOS updates do rectify some issues but if you were to consider that the board has to output video(out of the box) for the first time, then your display is the part that's out of place(or rather the board, in your case).

 

[Lodmot]

When sourcing boards for a laptop, you need to make sure you're working with the exact same model. If you can't flash the BIOS on the board, then you need to quit at that stage, since a bad BIOS or a failed/half baked update can and will cause you to end up with a bricked board, meaning another 200USD out of your wallet.

I'm fairly certain that the board you have might be an older version that what was in your laptop and perhaps that's what's conflicting with the display. Yes, BIOS updates do rectify some issues but if you were to consider that the board has to output video(out of the box) for the first time, then your display is the part that's out of place(or rather the board, in your case).

The weird part though is that the boards are the same model//revision number. The seller actually made me check this and send pictures of the original motherboard to him to confirm it... Thats why I was wondering if this might work. But it sounds like it's perhaps not the bios thats the issue, but rather a defect in the hardware itself. That's what i was afraid of... xD It took a month for that motherboard to come, so it will probably be another month to get a replacement for the replacement board.

I sent the ebay seller a message yesterday morning, but they haven't gotten back to me yet (and it occurred to me it's the Chinese Holiday, so that's probably more waiting time right there..) At this point, we're also considering just buying a new laptop. :/

 

[Lodmot]

Just wanted to write a follow-up post on this issue, for anyone that has the same model laptop.

It appears there are a couple BIOS revisions for this laptop that you have to look out for:

• BIOS 200 (TP500LNG) First release.
• BIOS 202 - Update EC FW
• BIOS 203 - Update EC FW
• BIOS 301 - Optimize system performance

I can confirm that my old motherboard and the new motherboard are both the same exact model, which is E162264. However my old board has BIOS 301, while the replacement board I bought contains BIOS 200. The strangeness occurs when you try to update the bios from BIOS 200 to BIOS 202 or higher--seems like you should be able to do it, but it flat out refuses to. It states that the model of the board doesn't match (TP500LNG vs. TP500LN). But doing a Google search for TP500LNG doesn't bring up any results for a different laptop model-- it all sort of loops back to the TP500LN page on ASUS's website (wtf...?).

Where I think the problem may be is the CM number, because my old board shows "CM1424", while the new board shows "CM1451". I'm not sure what that numbers entail, but I believe the eBay seller I bought the replacement motherboard from may have sent me the wrong board.

After sending them a message and going back and forth with them about the situation, they seem to be implying that I did something wrong and fried the motherboard. If the CM numbers are supposed to match, then it's not user error-- they sent me the wrong board. Lol. Trying to ask them about this number has been a struggle because the seller is of course based out of China, so there's a communication barrier that I have to jump through when coordinating with them (not an attack against them, it's just how it is).

Hopefully when all is said and done, I'll be able to find a solution before late March, as that is when my long-distance girlfriend has to leave to go back home-- and this is her laptop. But whoever has this particular laptop may want to be extremely careful when matching up the board model number if you're replacing the motherboard-- make sure all the text on the bottom matches EXACTLY before you make your purchase. Even when I sent the eBay seller pictures of my old motherboard, it seems they may have fumbled in giving me a slightly different variant of the same model board, that isn't compatible with the laptop itself or the same BIOS.

If worse comes to worse, I'll probably just buy my girlfriend a new laptop and salvage the 1TB SSD that I bought for her from the old laptop. And I'll probably avoid ASUS as a brand, because this isn't the first odd situation I've ran across with ASUS laptops. HP and Lenovo seem to be the biggest brands that are out right now, and I've had awesome luck with my Lenovo's, so I'll probably just get her that.

If anyone else wants to chip in, feel free. But this has been a good learning lesson for me.