Some information about HP T620 Plus Flexible Thin Client machines for network appliance builds...

nthu9280

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@BLinux - I read somewhere (may be pfsense forums) that pfSense is picky with WIFI cards, drivers etc and to avoid it for that function. Not sure if that's due to limitations of underlying BSD or something else.
 

BLinux

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@BLinux - I read somewhere (may be pfsense forums) that pfSense is picky with WIFI cards, drivers etc and to avoid it for that function. Not sure if that's due to limitations of underlying BSD or something else.
that's a good point, and i wouldn't be surprised if it were true. FreeBSD is a bit primitive by modern standards.

that said, my planned use is with Linux, and that seems to have much broader driver/hardware support.
 

nezach

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I was thinking it would be nice to have a VGA port since DisplayPort is not always available on the older monitors and based on HP documentation t620 machines might have a VGA+1 serial port instead of 2 serial ports. There is a 16-pin VGA connector on the board, however ribbon cable for this does not seem to exist.

There is a post on HP website from a while back asking about same thing
HP T620 Plus – need VGA ribbon cable - HP Support Forum - 5890670
 
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BLinux

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I was thinking it would be nice to have a VGA port since DisplayPort is not always available on the older monitors and based on HP documentation t620 machines might have a VGA+1 serial port instead of 2 serial ports. There is a 16-pin VGA connector on the board, however ribbon cable for this does not seem to exist.

There is a post on HP website from a while back asking about same thing
HP T620 Plus – need VGA ribbon cable - HP Support Forum - 5890670
that could be nice, but since my machine is running headless, i just reconfigured it to output to serial console. if i ever need to interact with it directly, i just need my laptop (which has monitor + keyboard/mouse) and a serial cable/usb adapter.
 

nezach

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yeah, I am going to use serial console as well, but it is nice to have dumb VGA as an option for when you forget your cables and adapters at home.
 

BLinux

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So after going to update my in-use t620's BIOS and realizing what a PITA it is, I developed an easier way. Some posts and HP readme's reference an easy to use "flash ROM" option in the BIOS, but none of my T620's have had this. note: all the below applies to both the t620 and t620 plus, same BIOS for both

Also, HP's site is a ****ing mess, as always (I do not miss having to use their servers). If you run through all the OS options on their drivers download page, it turns out the very latest BIOS version (released four months ago!) - v2.17, is hidden under "windows 7 embedded" - because it's HP and **** you that's why

I noticed the BIOS download comes with an EFI shell application to update the BIOS, so I simply used the open source EFI shell bin from the EDK2 project - https://github.com/tianocore/edk2 to create a bootable EFI shell image, and stuck the HP bios update efi application in the root of it, renaming it to update-t620.efi - I then wrote all this out to an ISO file linked here: http://fohdeesha.com/data/other/t620-bios-v217.iso

so just use your favorite tool to write that to a USB drive (GPT or MBR, doesn't matter), and EFI boot the thumb drive on the t620. Make sure EFI boot devices are enabled and secure boot is disabled in the bios settings. It'll boot to a simple EFI command line - just type update-t620 and it'll begin the BIOS update. Once it finishes, just power off/reboot and remove your flash drive
i must be the king of unable to boot T620+ machines....

I used 'dd' to write your ISO file to a USB drive and it isn't recognized as UEFI bootable device? I even went and just completely disabled legacy boot in the BIOS and now it just says there's nothing it can boot. what am I missing? Is this wrong:

$ dd if=./t620-bios-v217.iso of=/dev/sdj
 

fohdeesha

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I'm not sure, dd might not work with the ISO I made. I only tested writing it on windows with Rufus, but it worked with both MBR and GPT format type.

If you don't have access to windows you can create one from scratch, just format the flash drive to fat32 and make sure it's empty.

Then create a folder on the root of it called "EFI", then inside that create a folder called "Boot". Then inside that Boot folder place these two files: index - powered by h5ai v0.29.0 (https://larsjung.de/h5ai/) (right click and save as on each file to save it unmodified somewhere on your PC)

So final result should look like this, assuming the flash drive is drive G (forgive the windows parlance): G:\EFI\Boot

then in that final Boot folder should be those two files
 
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BLinux

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I'm not sure, dd might not work with the ISO I made. I only tested writing it on windows with Rufus, but it worked with both MBR and GPT format type.

If you don't have access to windows you can create one from scratch, just format the flash drive to fat32 and make sure it's empty.

Then create a folder on the root of it called "EFI", then inside that create a folder called "Boot". Then inside that Boot folder place these two files: index - powered by h5ai v0.29.0 (https://larsjung.de/h5ai/) (right click and save as on each file to save it unmodified somewhere on your PC)

So final result should look like this, assuming the flash drive is drive G (forgive the windows parlance): G:\EFI\Boot

then in that final Boot folder should be those two files
thanks... that's pretty much what i did right after posting the above. that seems to work just fine. thanks!
 

BLinux

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As an experiment, i picked up a HP 708778-001 65W AC Adapter to try with the T620 Plus and it does not work. The power button blinks red. The specifications are about the same except for Amperage (basically 65W vs 90W), so I'm surprised it doesn't work. I figure the box is only using 20W or less, so I thought the 65W would work... any thoughts?
 

fohdeesha

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are you sure the voltage it's putting out is the same? if it's that simple then yes it should work, I don't think these do any kind of signalling (there's only two pins)

I'm going to take a closer look at mine
 

fohdeesha

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Measured the output and even though the provided PSU is rated at 19v, it's only putting out 14v, and that's floating (no load). Briefly tried to open the brick to do some more probing but it's completely glued shut with potting compound

When you look at the two plugs for each, does the nonworking one look different? EG is the center pin shorter? The DC jack that's soldered to the motherboard has 3 pins/traces coming out of it, so I dunno what the third one would be. it could be switch/contact that only gets closed when a longer pin is inserted. will look more
 

BLinux

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@fohdeesha I'll take a multimeter to the PSU later to see what I read. The 90W says 19V output on the label, the 65W says 19.5V output on the label. I figure between 19V vs 19.5V that wouldn't really make a difference. 14V seems weird... i'll check both later and report back.
 

fohdeesha

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EDIT: nevermind, just confirmed BOTH power supplies do indeed have 3 contacts, one of them being a sense pin - the 14v I was measuring was between the outer metal and the center pin which was 14v- so the center pin seems to be a sense pin. If you measure from the outer metal ring (ground) to the inner metal (being careful not to touch the center pin) it measures the expected 19V - making the inner metal the positive contact.

I would imagine the voltage between ground (outer metal) and the center sense pin is different between the two power bricks and that's how the t620 knows what's plugged in
 

Marsh

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HP system have ability to query the power wattage of the PS. It would either pass go or no go.