Unidentified powerconnector on not even a very old desktop

[XistenZ]

I'm troubleshooting a desktop that is "dead", it won't power on at all so naturally I start with testing with a different PSU. With a working PSU (the old one is later confirmed 100% dead) atleast a small light on the motherboard lights up when the PSU is turned on. The computer however won't react, no fans, no harddrives spinning, nothing. I change the CPU and still nothing.

The motherboard have the standard 24-pin connector and 8-pin for the CPU, but it also have another 8-pin connector but it looks like an extended power connector for a floppy

I'm wondering what it's for? Is it needed to power the motherboard and/or CPU and that's why the desktop won't turn on? I want to be able to confirm that the motherboard is also dead, but if this connector is somehow needed to power on the whole thing I can't do that.

***EDIT***
The model of the desktop is 'Fujitsu Esprimo E7935', and the old PSU with the funny connector is 'HP D2508E0'

 

[Lutfij]

Out of all the info provided, couldn't it have been more easier to post a picture of your motherboard's power connectors and the old PSU's power connector? It could also indicate that the PSU and the motherboard are both proprietary meaning one will not work without the other(in spite of finding a near similar component to replace the old one).

 

[dumb_man]

Floppy drive power supply

 

[XistenZ]

OP updated with relevant images

 

[Lutfij]

Yeah it's a proprietary header and only the same PSU you removed will cater to it. Current or even aftermarket PSU's lack that. Google image searches of your system show it to be as unique as the Dell OptiPlex's. PITA to upgrade and even worse to source replacement parts.

 

[XistenZ]

Yeah it's a proprietary header and only the same PSU you removed will cater to it. Current or even aftermarket PSU's lack that. Google image searches of your system show it to be as unique as the Dell OptiPlex's. PITA to upgrade and even worse to source replacement parts.

So it's a kind of "don't you dare upgrade your machine, buy a new one instead"-securitymeasure? This measly little connector is actually needed for the desktop to turn on at all?

 

[Lutfij]

Well, sort of. In an office environment if you prevent any upgrades(by the end user) you eliminate any anomaly's and ofc false claims for warranty coming through. You haven't worked with Dell's OptiPlex's...you're even forced to stick with the existing case since the front panel wiring on the SFF units don't correspond to a standard cases front panel connectors. Finding their correspondence's will take a load of time and ofc some dead brain cells to accomplish as will be the case if you took a multi meter and found out the voltages across each pin on that(aforementioned) proprietary connector.

 

[King_V]

I don't suppose by any chance that it's simply a matter of a fuse inside the original power supply having blown, is it?