I just ran into this issue. it is in fact maybe a motherboard issue. Note if your out of warranty they your best bet is to do it yourself if your tech savvy. First I recommend to replace the CMOS battery which you can get one from a rite aid etc. Now bare in mind that once you replace the battery and you go through all the steps below this paragraph, then later the information is lost a again meaning you get that serial error then you can determined that the motherboard is really bad. Second copy down the: S/N: maybe on sticker at bottom P/N: maybe on sticker at bottom Model# maybe on sticker at bottom PCID which is located under the battery via white sticker Next what you want to do is to re-write these to the bios. go to the page below and download the Rufus software to create a bootable USB drive. Also you will need to download the file "HP DMI" All the links to these files can be found here : https://www.geekslab.it/hp-serial-number-not-found-fix-solution/?lang=en and there is a readable instructions...
I was so glad that there is separate digitizer as my warranty was finished. The screen was cracked so bad i got !#^&@@ and pull off some of it and noticed that the digitizer was separate and my god the LCD was perfectly intact. At that point I decided to get my replacement digitizer from ifixit. I was very happy that it came with the adhesive already around the edges. I followed the repair guide but still it took me almost 2 hours as I was being extra carful not to damage the LCD. For future references tape the broken screen with clear tape then proceeded to remove it as it will keep the little shards from flying over the place and most of all make sure to use protective eyewear as I said those little shards will fly as I got one in the eye.