Hewlett Packard Laptops – 15AC121DX Not Working Troubleshooting

A computer repair customer brought me a Hewlett Packard laptops model 15-AC121DX that will not work. This is actually one of my repeat customers. She claimed that a Windows 10 update was installing and the next thing she knew the laptop no longer booted.

I was able to get this Hewlett Packard laptops 15-AC121DX working again. I tried the inital taking out the laptop battery, disconnecting the AC adapter, and then holding the power button for 30 seconds routine. I took off the bottom cover of this laptop.

There are twelve screws that you will need to remove. Also, there are two screws under the battery. Once I removed the bottom cover, I removed the Random Access Memory.

This Hewlett Packard laptops model 15-AC121DX still would not start the Power on Self Test. I stripped down this laptop to the bare bones. I took out both memory modules, hard drive, optical drive, and even the wireless card.

This laptop still would not power on successfully. I did notice that I finally got an orange light to turn on with just the AC Adapter plugged in. This tells me the laptop battery was charging.

When I removed the laptop battery a solid white light turned on. This tells me that the AC adapter was good and power to the computer was being received. However, each time I pressed the power button, the case fan would not turn on and no other lights would display.

Finally, I tried installing some spare DD3 memory I had. I finally got this laptop computer to at least attempt to power on. I noticed the power button would blink three times.

Also, I noticed a Caps Lock key would blink three times as well. I performed a quick Google search and found that this led blink code meant that this was a Random Access Memory issue. I decided to install the original memory that came with this 15-AC121DX laptop.

Low and behold I was finally able to get this computer to peform the power on self test. I was able to see a message on the laptop display screen. There was a problem with the board ID being incorrect in the Basic Input Output System.

I tested both memory modules in both slots. I narrowed it down to a bad memory module. Also, I had to enable “legacy support” in the BIOS. You press F10 to get into the BIOS on this particular HP laptop.

I was finally able to get Windows 10 to boot successfully. I attempted to upgrade the BIOS to version F.23 but had to run the flash a second time before it succeeded. Also, I was able to finally get the laptop battery to fully charge.

I have one more additional problem. Windows 10 fall creaters update will not install successfully to Windows 10 1709. Once I fix this problem, I can return this laptop to the customer. I may not be able to clear that BIOS error.

However, my customer now has a working HP laptop with Windows 10 operating system. If the battery is bad or only charges intermittently, then they can order a replacement.