Displayport in HP Compaq Elite 8300 All-in-One Desktop PC

[WoodL]

I have an old Compaq Elite 8300 All-in-One.

What I want to do is to output the hdmi display of a dell laptop (for my work) to the monitor of this all-in-one. 

I've tried to connect from laptop to display docking, then from display docking displayport to this all-in-one displayport. But the laptop just cannot identify the second monitor.

I'm not sure if it's a problem of my all-in-one displayport?

I've also tried connecting from displayport to laptop hdmi directly, expecting this multi mode displayport can output to hdmi. But this time the all-in-one cannot identify the second monitor.

Did I do something wrong, or the displayport is dead? Anything I can do to verify if it's still functioning?

Thanks in advance.

[savvy2]

ONLY SOME MODELS OF AIO do that , Not All.

Some AIO PC ALLOW THAT AND  PORT PARKED HMDI-IN CLEARLY THERE.

AND SOME A BUTTON TO GO TO MONITOR MODE.

You posted and NO PC told

it has a full model and product ID, and that ID tells what you have inside. and

the mobo inside is first,  as those jacks seen there or missing are MOBO first facts (look)

I can not read the manual too you unless full PC product ID is told. sorry.

power on , hammer Esc and find the info page, and full product ID. that way.

[WoodL]

Hi @Savvy2 I've viewed the info page it's what I found.

Product Name HP Compaq Elite 8300 All-in-One PC

SKU Number C4K24PA#ABG

Where could I find the manual?