Acer Aspire VN7-591G-792U will not turn on...again.

fighthouse
fighthouse Member Posts: 4 New User
I picked this laptop up almost 5 years ago, and for the most part it has been a very reliable device...up until about a year ago. I was in the middle of gaming, and it had shut down by itself. Nothing I tried would turn it back on, even after I did all the basic and slightly advanced troubleshooting. I verified that every individual component outside of the motherboard was working properly (including AC adaptor), and that the fans wouldn't even spin if I tried to ONLY power on the motherboard. When I broke out the multimeter, everything seemed normal until I measured the AC adaptor voltage AFTER connecting it to the motherboard. The voltage of the adaptor would drop, and after I unplugged it and plugged it back in the voltage would go back to normal. It seems like something on the motherboard was inhibiting the adaptor from properly supplying power to it.
After a couple of months of frustration, I eventually bought a replacement motherboard for more than I would have liked, and after installing it the laptop powered up like nothing ever happened. I blissfully jumped back into the games that my older spare laptop couldn't handle. Everything worked great...

...until tonight. The laptop powered off again in the middle of a game, and my memory reminded me that no amount of troubleshooting I performed (short of replacing the mobo) would get it going again. The last hour of disassembly and testing has proven that to be correct.

Google informed me that other people have had this issue with other Acer devices, but the end of those stories is always missing. I was wondering if anyone else has experienced this same issue, or can provide more insight as to what on the motherboard is specifically causing it. I could be just dangerous enough at this point to break out the soldering iron and replace some mosfets if need be.

Answers

  • StevenGen
    StevenGen ACE Posts: 12,687 Trailblazer
    edited February 2021
    I picked this laptop up almost 5 years ago, and for the most part it has been a very reliable device...up until about a year ago. I was in the middle of gaming, and it had shut down by itself. Nothing I tried would turn it back on, even after I did all the basic and slightly advanced troubleshooting. I verified that every individual component outside of the motherboard was working properly (including AC adaptor), and that the fans wouldn't even spin if I tried to ONLY power on the motherboard. When I broke out the multimeter, everything seemed normal until I measured the AC adaptor voltage AFTER connecting it to the motherboard. The voltage of the adaptor would drop, and after I unplugged it and plugged it back in the voltage would go back to normal. It seems like something on the motherboard was inhibiting the adaptor from properly supplying power to it.
    After a couple of months of frustration, I eventually bought a replacement motherboard for more than I would have liked, and after installing it the laptop powered up like nothing ever happened. I blissfully jumped back into the games that my older spare laptop couldn't handle. Everything worked great...

    ...until tonight. The laptop powered off again in the middle of a game, and my memory reminded me that no amount of troubleshooting I performed (short of replacing the mobo) would get it going again. The last hour of disassembly and testing has proven that to be correct.

    Google informed me that other people have had this issue with other Acer devices, but the end of those stories is always missing. I was wondering if anyone else has experienced this same issue, or can provide more insight as to what on the motherboard is specifically causing it. I could be just dangerous enough at this point to break out the soldering iron and replace some mosfets if need be.

    These sorts of problems happen because your Aspire VN7-591G-792U has problem with either your charger overvolting and/or shorting out and is damaging your power circuitry through your AC jack plug and cord (that can be replaced) and that connects to the mobo, which charges the battery or the battery is shorting out (check all these connection if they are not shorting out to the mobo)  there must be something wrong within that area as putting a new mobo shows that its not the mobo that is at fault. Btw, I've had these sorts of problems.

    Also and with the VN7-591G-792U it hasn’t got many cooling vents and lacks cross ventilation (very common thing with older Acer Gaming laptops) and if you want to play hard core games that take allot of power and create heat then I would mod the laptop with extra cooling vents and use a tablet cooler or make a tablet cooler with extra high capacity fans to keep this laptop cool. I've had these sorts of experience(s) with a few Acer laptops that shorted out (for no reason) but mainly overheated to tremendous high temps playing games (even to an extent that you couldn’t even touch the cpu/gpu and power jack part of the laptops but, these laptops just turned off and they always could be rebooted.

    See if you can revive this laptop by changing what I’ve suggested above like the charger, battery and AC jack and cord and see if that fixes this problem? Otherwise you have blown another mobo unfortunately which is very unusual and rare, irrespective of what others say, as people only complain when they have problems as this is not the norm with Acer laptops if you know what mods to do and how to use them, btw this is a guide to the Acer Aspire V Nitro VN7-591G Disassembly. Good luck, hope this helps. 


     AC power jack plug and cord connected to mobo                         AC power jack plug at mobo, check this part


    Check battery if working 100% or its pug if its corroded or faulty.


    The Aspire VN7-591G hasn’t got adequate cooling vents and cross ventilation for a gaming laptop

                                                                                              

  • fighthouse
    fighthouse Member Posts: 4 New User
    I agree that this laptop is not designed very well to disperse the heat it generates. The couple of times I had it on my lap during gaming almost made me look for burn marks afterwards.

    I was gaming both times the device shut off, so I think it could be likely the heat being generated that made it shut off. However, it should have turned on after a bit when it returned to a safe temperature.

    I found a schematic online for the motherboard, but I have zero experience troubleshooting mosfets/fuses and circuitry on mobos. I'm not very confident I can diagnose the specific issue/mobo component that is at fault.
  • StevenGen
    StevenGen ACE Posts: 12,687 Trailblazer
    edited February 2021
    I agree that this laptop is not designed very well to disperse the heat it generates. The couple of times I had it on my lap during gaming almost made me look for burn marks afterwards.

    I was gaming both times the device shut off, so I think it could be likely the heat being generated that made it shut off. However, it should have turned on after a bit when it returned to a safe temperature.

    I found a schematic online for the motherboard, but I have zero experience troubleshooting mosfets/fuses and circuitry on mobos. I'm not very confident I can diagnose the specific issue/mobo component that is at fault.

    fighthouse check those components that I've mentioned above first e.g. the AC plug and cord and its plug at the mobo if its not shorting and/or blown, check your charger and battery, as that is where you should start to diagnose this problem. If all is good then it’s somewhere in the power circuitry in the mobo that you need a technician to diagnose with proper tools as to know where the exact circuitry is shorted and/or blown. All these things and parts are something that you could not get off the shelf, as you will need to replace the mobo and/or and maybe, scavenge from your other mobo, if these parts haven’t blown either and in the same way?

    This is a complicated job that you need technical experience and experience with and the proper tools to diagnose.  Good luck and if you get this thing going (or persist with this laptop?) make sure that you paste the cpu/gpu with a good paste (like the Thermal Grizzly NEW Conductonaut Extreme Paste) and mod the bottom case with extra and appropriate vent holes (like I've done to a V3-571G that overheats the same) to get good cross flow ventilation and also get or make a good tablet cooler as that is how these laptops can operate cooler in extreme gaming as they overheat to alarming temperatures, unfortunately.


  • Easwar
    Easwar Member Posts: 6,727 Guru
    Hi fighthouse,

    # Power drain,
    At bottom of the laptop there will be tiny pin hole with battery symbol close to it. Insert pin or paper clip into that hole press and hold it for 30-40 seconds.​

    Check this T/S and post the result.