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EliteDesk 800 G3 TWR

Hi guys


I`ve got used EliteDesk 800 G3 TWR unit, but unfortunately there is no 3.5" hard drive cage in it. So I'm looking for it, but cannot find anything at ebay or anywhere else.


So maybe someone can tell me a partnumber of that detail?

I believe it will be a great help in my searching.

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Here you go... Welcome, and good luck on your project.


EDIT:  The QuickSpecs HERE from HP for your PC indicate it has a M.2 form factor socket and also a 2.5" form factor drive bay... do your homework about those using the technical and service manual for the tower version HERE about what type of M.2 stick would work (SATA?  NVMe? Z Turbo Drive G2?).  If, instead, you choose to have your boot/applications drive as a SSD in the single 2.5" drive bay make sure it is a SATAIII type SSD, and also that its SATA data cable is connected to a SATAIII bandwidth socket on the motherboard.  Finally, HP sometimes uses four smaller black M3 threaded elastomeric-metal special slider screws similar to the blue ones shown below for some of the HP 2.5" form factor drive bays... those are harder to find but you'd need them for use of a 2.5" SSD in such a situation because all of their mounting screws are M3.


The inside of your case shows it does not use the traditional HP green or black 3.5" form factor plastic sliders.  Rather, it has built in metal rails into which 3.5" form factor drives slide (assuming you have four blue elastomeric/metal #6-32 UNC threaded screw devices at the 4 corner holes of each drive).  The picture below shows the lower drive bay with room for two 3.5" HDDs.  Higher up you can see that HP built in 4 threaded holes for spares of those special screws, so you might already have some handy:


1 EliteDesk 800 G3 TWR case inside.jpg


I don't know if the box has another area for adding a 2.5" form factor HDD or SSD... you want to be running off a SSD if at all possible, and using a SATAIII speed SATA data cable (assuming there is no build in M.2 NVMe socket).  Thus, you would want to have a nice 2.5 to 3.5" form factor adapter and the ones we like a lot are from HP, found on eBay for about 10.00 each, via search for hp 2.5 to 3.5 adapter or 654540-001 or 654540-002, shown below:


2 654540-001 654540-002 adapter.jpg

That adapter gives you exactly the dimensions of a 3.5" HDD into which your 2.5" SSD is inserted.  Four M3 threaded short screws usually come with each of those... used in the four short M3 metric threaded corner holes present in all 2.5" form factor HDDs and SSDs (and optical drives).  


The 3.5" form factor HDDs and SSDs instead use #6-32 UNC threaded machine screws, and for this compact business class PC HP chose to use their common blue elastomeric rubber-cushioned small rounded metal slider screws that allow you to slip the front two into the drive bay's metal rails, slide forward (tilted up at the rear to get started) and finally tilt down to slip the rear two slider screws into the rails, and click forward into final position.  Clever space saving trick, and from HP these special screws are "450712-001 Hard drive isolation grommets (Blue color) - Contains four grommets".  Those are easy to find also on eBay if you don't have enough spares still inside the case.  Here is what they look like up close, and they are best screwed in using a Torx bit, but a flat bit also can be used:


3 450712-001 6-32 blue elastomeric slider screws.jpg














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Thank you very much for your reply!


I think its better to show you what I have:

20211127_212556[1].jpgAs you see, no lower drive bay. 😞

And no that small elastomeric-metal black M3 screws (could be helpful at least for adding one 2.5" drive).

And existing four 450712-001 screws with blue elastomer are absolutely useless in my case, because an existing bay needs only that small m3 ones.


That is why I need to try to find that lower bay... Partsurfer was not so helpful as I expected - no case details, just bezels.

Serial number [personal info removed], product number 1FU44AW.

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Nice clean machine!  Very little use it appears.


Yes, the HP PartSurfer does not list all the parts for a HP computer.  What you are missing on deeper review is the EliteDesk 800 G3 TWR hard drive cage.  Take a look at this YouTube video from HP, at 5 minutes in, HERE :



You should download this, also, for your reference, HERE :  

Hardware Reference Guide HP EliteDesk 800/880 G3 TWR Business PC


From that it appears there is a place to mount a 2.5" SSD at the upper edge of the optical drive bay, and there also are 5.25 to 3.5 and 5.25 to dual 2.5" adapters that can sit behind your front bezel as a way to mount drives given that your official drive cage is missing.  I'm sure you want to get that up and running ASAP, so you could even start now with some industrial grade velcro tabs.


For both a 2.5" drive and a 5.25" bay adapter you may need to use the M3 slider black screws.  HP has made these in several dimensions, and the most common can be found on eBay by a search for "Lot of 4 HP Blue 2.5" Hard Drive Mounting Screws USDT USFF Desktop Mini Small"     It is the screw that is black for the metric ones, and the threads are finer....  shown below:




I could not find any of your official drive cages for sale... later these PCs will be broken down more frequently for parts and you'll likely be able to locate one.   If you have access to one with the drive cage intact they usually will have a HP assembly part number stamped in the metal for reference.  You might also contact the seller about the missing part and tell them you want that part that is supposed to be present.


If it was me and getting a cage from the seller was not possible I'd start with velcro to get going with a SSD, and order up a 5.25" bay adapter to hold drive(s)... Icy Dock makes good ones.  The HP ones I have are the best, but rare to find these days.  There are 5.25" bay adapters that don't require that you change anything along your front tower bezel... they are for internal mounting of drives.

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Velcro seems to become the best temporary decision for my 2.5" drive! ))) So thanks again!


I just ordered at aliexpress 4 black-blue screws as on your photo, but it will take time to come...

As about 5.25 to 3.5 adapters, Icy Doc bays looks really nice, maybe I'll choose something. The front besel is very simple to remove, but I guess I have no choice as to remove the front metal shield before installation. According to manual, I have to install four M3 screws in the lower holes of the bay (or full-size DVD), and they will become like guide rails for the bay, so it cannot be done from the inside.


And still trying to catch that lower bay, or cage, or how it is called, somewhere in the future...

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I don't believe this unit uses a drive cage for the 3.5 drive i suspect it uses the blue  (or black) HD mounting screws



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Yes, silver screw ones for 3.5" form factor HDDs with their #6-32 UNC threaded mounting holes, and black screw ones for SSDs/2.5" form factor HDDs with their M3 metric threaded holes.  The YouTube video I referenced above, at https://youtu.be/7VuYsQRY8Es, shows exactly this G3 tower workstation and starting at 5:04 minutes in it shows that the lower "drive cage" can rotate up and be removed independent of the upper combined optical drive/2.5" form factor cage.


Someone did that with his G3 tower, and never put that cage back in so he needs to find another place to mount some drives.  Of interest I found another HP video suggesting that the G3 and G4 tower versions both have a combined long 3.5" drive cage/optical drive cage that rotates up as a single unit.  That is a mistake... that is present only in the later G4 tower version.  The G3 tower video link above shows the lower 3.5" drive cage is fully separate and can be removed for drive manipulations.  Not a great idea, and lasted only this single G3 tower generation:


Removable drive cage.jpg

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ok, the HP video does show a drive cage attached above the optical/HD cage


until he can source the correct missing cage he can place a HD in the existing cage that also holds the optical drive


if he can't locate the correct one a 3rd party cage like the one below can be adapted to mount by drilling the cages 4 mounting holes into the hp case



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Another valuable answer! Thank you too!

Currently I'm settled on the variant of using 5.25-3.5 adapter for 3.5" HDD and present 2.5" bay for SSD.

And if I'll need more 3.5" drives, I have nothing left to do than to drill halls and mount another bay... or to use more velcro. )))

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