HP 20-c020 error code

[NotABigGamer]

I got a hp 20-c020 all in one from a friend to keep. However when I turn it on before it boots it lets out a ear piercingly loud error code. It goes 3 long lower pitched beeps then 4 shorter higher pitched ones. It repeats 5 times then turns on like normal. I have taken it apart and unplugged the speakers. I have tried with and without anything plugged into it. The only think that I can think of is that I am not using an oem power cable. Would that effect anything? Is it something else? 

Thanks!

[manikyath]

if you dig into the documentation for the AiO you'll probably get some exact notes about this (HP's pretty good with that, contrary to popular belief..) but a quick google search suggests that it's probably just a dead CMOS battery.

[NotABigGamer]

1 hour ago, manikyath said:

if you dig into the documentation for the AiO you'll probably get some exact notes about this (HP's pretty good with that, contrary to popular belief..) but a quick google search suggests that it's probably just a dead CMOS battery.

Ok I will try that and see what happens. Thanks!

[NotABigGamer]

7 hours ago, manikyath said:

if you dig into the documentation for the AiO you'll probably get some exact notes about this (HP's pretty good with that, contrary to popular belief..) but a quick google search suggests that it's probably just a dead CMOS battery.

I replaced the battery and no luck. Still the same issue. Where can I find the documentation for this AIO?