Can i add an extra 1TB HDD in my pavilion x360 without removing my 128GB SSD?

[Priyom]

I want to add 1TB HDD in my device without removing my 128GB SSD and if i can, which HDD type/model/configuration will be compitable with my device?

[Huffer]

Here's your Service Manual:

Manual

I have actually had my hands on one of this model series. The one I had came with a hard drive and I added first an NVME M.2 disk and then settled upon an Optane module and both worked great. However, mine came with the adapter board and cable for the 2.5 inch disk and yours will not have because it was shipped with an M.2 disk only. 

Hard drive foil L20549-001 (9) Hard drive rubber gasket Full-featured models L18225-001 Full-featured plus models L18226-001

(4) Hard drive cable L18218-001

You need the above parts and unfortunately the parts with a part number commencing with an "L" have not entered the supply chain and are virtually impossible to find. 

https://parts.hp.com/hpparts/Search_Results.aspx?mscssid=FA173545BE304374B52147DD7A7E9FEF&SearchIn=P...

Seems "L" stands for "Lost". Your best bet to add storage is to replace your M.2 SSD with a larger capacity version I am sorry to say. 

Post back if you need more help and please accept as solution if its the info you needed. 

[Jmsnoopy650]

I'm tryng to do the same thing. How do i know whether i have a Full-featured model or a Full-featured plus model?