[REQUEST] Asus Strix Gaming Laptop Won't Start After LCD Replacement

[Appletax]

Asus Rog Strix G513QR - MB98Q

Client brought me a laptop with a broke LCD from dropping it that also has issue issues with shutting down during heavy workloads. He was using it with an external monitor. He used it overseas, too, with 220 volt electricity. He brought me a new, OEM replacement power adapter.

I replaced the LCD and now it won't turn on at all. I didn't have to take apart the laptop to replace the LCD and I just dealt with one monitor cable.

Did a hard reset (hold down power button for 40+ seconds) and did a hard reset after disconnecting the internal battery.

Not sure what to do at this point. The battery charging indicator LED is on.

 

[Larry Sabo]

I replaced the LCD and now it won't turn on at all. I didn't have to take apart the laptop to replace the LCD and I just dealt with one monitor cable.

Was the battery disconnected (or disabled in BIOS, if that's an option) when you changed the LCD? If not, perhaps the backlight fuse or a LCD supply voltage component is blown. Can you measure voltage on the LVDS connector?

 

[Appletax]

Was the battery disconnected (or disabled in BIOS, if that's an option) when you changed the LCD? If not, perhaps the backlight fuse or a LCD supply voltage component is blown. Can you measure voltage on the LVDS connector?

I messed up. I didn't disable the battery first. But, even if the LCD had damage, the computer should still at least power on, yes? And maybe work via HDMI external monitor.

 

[Larry Sabo]

But, even if the LCD had damage, the computer should still at least power on, yes? And maybe work via HDMI external monitor.

Not neccesarily. I've made the same mistake with a Lenovo Thinkpad and it blew one of the supply rails and that prevented the laptop from powering up. If you are lucky, it just blows the fuse on the 19v supply to the LVDS connector. I guess you (and I) were unlucky.

 

[Appletax]

Not neccesarily. I've made the same mistake with a Lenovo Thinkpad and it blew one of the supply rails and that prevented the laptop from powering up. If you are lucky, it just blows the fuse on the 19v supply to the LVDS connector. I guess you (and I) were unlucky.

This is all new to me.

Sounds like the LVDS connector are the two connectors that the display cable connects to - not the cable itself.

How do I test the LVDS voltage using a multimeter? My understanding is that I would need a special pinout diagram detailing what every single little pin does.

YouTube and Google searches have not helped me at all.

If my testing showed a blown fuse on the 19v supply to the LVDC connector, would I have to replace the whole motherboard?

I cannot solder if that's what's required to fix it.

This sounds like a big pain in my arse

 

[Appletax]

Do these pictures help?

 

[Appletax]

I don't know what to do so I just undid all my work and am giving the laptop back to the client and recommending an alternative repair company. This is beyond me. I wish I knew what to do to fix this.

 

[Larry Sabo]

The LVDS connector is the connector on the motherboard into which you plug the video cable from the screen. I don't have a schematic for this model so can't help locate the fuse normally located near the LVDS connector. It may be the one marked R010 beside the LVDS connector, in this picture. That video cable plugs into the LVDS connector. You need to be able to use a multimeter to see if that resistor is open circuit or around 0.1 ohms. If it's open circuit, you need to replace it with a new resistor. If it's not open circuit, a schematic and further testing are required. Otherwise, motherboard repair or a new motherboard is required.



Edit to add: Since the laptop won't power on at all now, it's likely more is wrong than just a blown video supply fuse, so will require MB repair/replacement. I assumed you tried with an external monitor and got the same result.

 

[Appletax]

The LVDS connector is the connector on the motherboard into which you plug the video cable from the screen. I don't have a schematic for this model so can't help locate the fuse normally located near the LVDS connector. It may be the one marked R010 beside the LVDS connector, in this picture. That video cable plugs into the LVDS connector. You need to be able to use a multimeter to see if that resistor is open circuit or around 0.1 ohms. If it's open circuit, you need to replace it with a new resistor. If it's not open circuit, a schematic and further testing are required. Otherwise, motherboard repair or a new motherboard is required.

View attachment 14308

Yea, this is beyond me. Thanks for helping, tho.

Hopefully the client can find a tech that can handle this situation. I wouldn't even want to replace the mobo. It has what looks like 5 antennas attached to the board. I have broke these before because they're super fragile. They should stick to only using Wi-Fi chips that go into slots so that they can easily be replaced if the antenna port is broken rather than needing to solder the port back on.

This makes me never want to do another screen replacement on anything. It's almost always such a pain in the butt.

One thing is for sure, if I ever do another one, I will be sure to disconnect the battery.

 

[frase]

This is all new to me.

Sounds like the LVDS connector are the two connectors that the display cable connects to - not the cable itself.

How do I test the LVDS voltage using a multimeter? My understanding is that I would need a special pinout diagram detailing what every single little pin does.

YouTube and Google searches have not helped me at all.

If my testing showed a blown fuse on the 19v supply to the LVDC connector, would I have to replace the whole motherboard?

I cannot solder if that's what's required to fix it.

This sounds like a big pain in my arse

Maybe as you did not dk the battery, unfortunately maybe unbeknownst to yourself a bit of metal from a cable, maybe Wi-Fi antennae has accidently touched the mainboard. I usually join these buggers together and tape over the ends as to not allow them to go rogue. It can easily happen, It has happened to me before.

 

[gadgetfixup]

I have a stack of these boards from shops that didn't disconnect the battery doing screen replacement or didn't know how the battery disconnected and actually ripped the connector off the board. These screens are hot all the time, even when the laptop is off. They rely on the SIO to trigger the screen to light up. It doesn't matter how careful you are, you'll spike the SIO if you don't disconnect the battery. I have a SVOD4 to reprogram the SIO but not all the firmware is available. If the board is pricey, I'll order a donor and either swap the SIO or grab the firmware off the donor to reprogram the original. It's a bad design in my opinion but ASUS isn't the only one doing this. A lot of HP models have S0 hot LCD rails as well. Cheaper to keep the screen hot and have the SIO trigger mosfets on the LCD board than build the circuits on the mainboard, I suppose.

 

[britechguy]

I've recently had a ThinkPad and an HP gaming laptop, both of which required a BIOS "disconnect the battery" action to allow for safe access to anything inside.

I agree and think this is an insane design choice, but it's becoming more common. You're supposed to do it even before removing the battery connector from the motherboard.

 

[Larry Sabo]

I have a SVOD4 to reprogram the SIO

Yikes! Can't believe what these cost! One would need to reprogram a lot of ECs to make it worth having.