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

[Khaveer]

Could you measure how thick this type of washer would need to be since you should have both the factory and traditional screws?

I can check it sometime next week. The t620 is a key part of my production network atm and I really don't want to take it down before I receive parts needed to get my main host back up.

 

[Samir]

I can check it sometime next week. The t620 is a key part of my production network atm and I really don't want to take it down before I receive parts needed to get my main host back up.

Makes sense. If you can measure the thickness, I'm sure I could find the part number at digikey/mouser or maybe even home depot/lowes.

 

[cleonard]

I gave up on finding screws as my unit came with none. I used a small piece of double sided foam mounting tape on the M.2 SSD. Mine is only a $20 regular T620, so the more permanent install isn't much of an issue for me.

If the pluses were not over $100, I would get one.

 

[N3RO]

Hello,

Looking for one HP T620 Plus for a Pfsense build.

Any considerations or other checking before buying? Hardware revisions, Firmware versions, PSU, etc.?

The deal I'm currently watching has 16GB SSD, 4GB RAM and NC365T NIC.

Thanks

 

[Khaveer]

Makes sense. If you can measure the thickness, I'm sure I could find the part number at digikey/mouser or maybe even home depot/lowes.

Sorry for the really late reply. I've finally found some time to take that t620 down and measure the screw. The part that goes under the m.2 drive is 1.3mm thick. I'm not sure if they make any washers/spacers with this thickness but if you find one please let us know.

EDIT: I've created a 3D model of the part. It's probably not very good for printing, for now I just tried to make reproduction of the original part to share some accurate dimensions. In the original part the screw goes through a metallic insert with an outside diameter of 3.5mm. One end of the insert is threaded just enough to keep the screw captive.

 

[Samir]

Sorry for the really late reply. I've finally found some time to take that t620 down and measure the screw. The part that goes under the m.2 drive is 1.3mm thick. I'm not sure if they make any washers/spacers with this thickness but if you find one please let us know.

EDIT: I've created a 3D model of the part. It's probably not very good for printing, for now I just tried to make reproduction of the original part to share some accurate dimensions. In the original part the screw goes through a metallic insert with an outside diameter of 3.5mm. One end of the insert is threaded just enough to keep the screw captive.

If you can figure out the washer size using this chart, then I think finding one at mcmaster-carr should be pretty easy:

Bolt Depot - USS and SAE Washer Dimensions

www.boltdepot.com

 

[keshav]

What is your typical power consumption for a t620 plus with an i340 t4 NIC?

Also have you noticed any performance degradations with running the latest bios?

 

[CIR-Engineering]

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?

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 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.

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

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

Interesting... I have a base T620 and I tested itsi 65W PS on the Plus model and no go. Blinking Red on power switch LED & some beep pattern.

Yeah, I can confirm on the working T620 90W PSU, I measured 20V from the outer ring to the inner ring and I measured 15.4V from the outer ring to the center pin.

Strangely, on the 65W PSU I got that does *not* work on the T620, I measured 19.4V from the outer ring to inner ring, and 14V from the outer ring to center pin. It doesn't seem like that big of a difference compared to 90W version?

It's probably not the voltage difference. Remember, we are talking about HP here. It is most probably the sense logic. The 65W power brick must be giving a different signal to the t620 than the 90W one gives and the t620 is just being dumb about it.

Guys you can make any power supply work that is 19.5v +/- something reasonable. On the PC board side, the power plug receptacle outer case is ground, the center pin is sense, and the two pins on either side of the center pin are positive. To trick the sense circuit, just mount a 330-ohm resistor between either of the positive terminal leads and the sense terminal lead. you can use any leaded resistor, but an SMD resistor will fit perfectly as in my photo below. I was experimenting with resistor values, but if I were doing this again, I would put the SMD resistor all the way down against the PCB instead of up on top of the terminals as in the photos (down there it would be cleaner looking and stronger). I'm to lazy to move it now ;-)



In my huge box of random power supplies, I found a couple with the correct barrel connector. The one I decided to use is an HP supply rated at 18.5 volts 3.5 amps (65 watts). Works great as I just have a 64GB M.2 SATA and I340-2T. 65 watts is plenty of power. I also had another supply that is 20 volts and like 200 watts, that supply worked fine too but is overkill.

 

[Samir]

Guys you can make any power supply work that is 19.5v +/- something reasonable. On the PC board side, the power plug receptacle outer case is ground, the center pin is sense, and the two pins on either side of the center pin are positive. To trick the sense circuit, just mount a 330-ohm resistor between either of the positive terminal leads and the sense terminal lead. you can use any leaded resistor, but an SMD resistor will fit perfectly as in my photo below. I was experimenting with resistor values, but if I were doing this again, I would put the SMD resistor all the way down against the PCB instead of up on top of the terminals as in the photos (down there it would be cleaner looking and stronger). I'm to lazy to move it now ;-)

View attachment 28422

In my huge box of random power supplies, I found a couple with the correct barrel connector. The one I decided to use is an HP supply rated at 18.5 volts 3.5 amps (65 watts). Works great as I just have a 64GB M.2 SATA and I340-2T. 65 watts is plenty of power. I also had another supply that is 20 volts and like 200 watts, that supply worked fine too but is overkill.

Granted there is some tolerance in circuits, but if you want the reliability, I would just get the appropriate genuine used power supply. You can find them as cheap as $5 shipped if you look for even 10 minutes.

 

[CIR-Engineering]

Granted there is some tolerance in circuits, but if you want the reliability, I would just get the appropriate genuine used power supply. You can find them as cheap as $5 shipped if you look for even 10 minutes.

Whatever voltage is input from the brick, is immediately being converted to 12 volt or less as soon as it hits the board. Part of my engineering firm’s work is component level repair. Believe me, this is fine. I just bought a unit for $57. Why spend even $5 more if I don’t have to?

I looked and couldn’t find HP’s blessed PS for less than $14 either…. I also was too impatient to wait for it . What I pulled out of my bin is also better IMHO. The smaller supply I’m using is still under utilized and thus much more efficient than the much larger 85/90 watt unit.

 

[Samir]

Whatever voltage is input from the brick, is immediately being converted to 12 volt or less as soon as it hits the board. Part of my engineering firm’s work is component level repair. Believe me, this is fine. I just bought a unit for $57. Why spend even $5 more if I don’t have to?

I looked and couldn’t find HP’s blessed PS for less than $14 either…. I also was too impatient to wait for it . What I pulled out of my bin is also better IMHO. The smaller supply I’m using is still under utilized and thus much more efficient than the much larger 85/90 watt unit.

It really depends on the conversion circuit, otherwise what's the point in having specifications for the power? Ime, engineers don't just do this for the heck of it.

All I can say about finding the power supply is 'you're doing it wrong'. A lot of times you just need to find a cross reference for a lesser known or more known part number. That's the way I've always gotten my cheap power supplies.

 

[CIR-Engineering]

It really depends on the conversion circuit, otherwise what's the point in having specifications for the power? Ime, engineers don't just do this for the heck of it.

All I can say about finding the power supply is 'you're doing it wrong'. A lot of times you just need to find a cross reference for a lesser known or more known part number. That's the way I've always gotten my cheap power supplies.

Do you have a part number for a lesser known in this case? I might buy one.

Also FWIW, my 18.5 volt PS measures 19.5 volts on my DMM. +/- 20% Isn't much to worry about on a PS like this. +/- 10% is of no concern.

 

[Samir]

Do you have a part number for a lesser known in this case? I might buy one.

Also FWIW, my 18.5 volt PS measures 19.5 volts on my DMM. +/- 20% Isn't much to worry about on a PS like this. +/- 10% is of no concern.

What's the original part number? I'll do some research.

Yikes! Is that a generic or branded power supply? Just curious as to why it's that far off.

 

[CIR-Engineering]

What's the original part number? I'll do some research.

Yikes! Is that a generic or branded power supply? Just curious as to why it's that far off.

My 18.5/19.5 volt is an HP OEM power supply from an old notebook.

I think the original part number for the T620 PLUS is TPC-I005-TC. But don't quote me on that because I am just quoting this guy:

Pardon Our Interruption...

www.ebay.com

 

[CIR-Engineering]

The other benefit of modding with a resistor to use any power supply is one may also desolder the stupid original barrel connector and replace it with an industry standard connector, or even solder the power supplies' wires directly to the PC board.

 

[Samir]

My 18.5/19.5 volt is an HP OEM power supply from an old notebook.

I think the original part number for the T620 PLUS is TPC-I005-TC. But don't quote me on that because I am just quoting this guy:

Pardon Our Interruption...

www.ebay.com

Interesting that the HP power supply is that far off on voltage.

I looked up this part number in the pictures and then checked HP's partsurfer and came up with 843233-001 as being the 'current' part number. I then checked what other parts this power supply is used with and it noted the T730 so I searched on ebay for T730 power supplies and came up with more part numbers, including some oem numbers to check.

Here's a list of all the part numbers I came up with and searched:

750112-001
750347-001 --> 843233-001
TPC-LA561
PA-1850-07HA

708779-001
708993-001
TPC-LA56
PA-1850-06HB

929818-003
843233-001
ADP-85LB
SU10473-15009

929818-001
843233-001
TPC-LA561
PA-1850-07HB
KU10462-14011

Searching all these on ebay including completed sales results in $11 shipped being the cheapest (which is about normal for used power supplies that are this high in wattage). Searching for TPC-LA56 and TPC-LA561 resulted in these current sales at $11 shipped:

Original HP 85Watts 19.5V 4.36A AC Power Adapter Model TPC-LA56 #U1206 | eBay

Find many great new & used options and get the best deals for Original HP 85Watts 19.5V 4.36A AC Power Adapter Model TPC-LA56 #U1206 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

HP Laptop AC Power Adapter TPC-LA561 85W 19.5V 4.36A #U8451 | eBay

Find many great new & used options and get the best deals for HP Laptop AC Power Adapter TPC-LA561 85W 19.5V 4.36A #U8451 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

HP Laptop AC Power Adapter TPC-LA561 85W 19.5V 4.36A #U8451 | eBay

Find many great new & used options and get the best deals for HP Laptop AC Power Adapter TPC-LA561 85W 19.5V 4.36A #U8451 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I'm sure this could be drilled down further because I saw stuff like this one that sold for $6.10 shipped, but that I'd have to research the part numbers for:

Genuine 65W 19.5V 3.33A HP Laptop Charger AC Power Adapter 751789-001 751889-001 | eBay

Find many great new & used options and get the best deals for Genuine 65W 19.5V 3.33A HP Laptop Charger AC Power Adapter 751789-001 751889-001 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Then I thought for a second and T730 didn't sound right so I searched for 't620 power supply' and landed this listing for $9 shipped:

Pardon Our Interruption...

www.ebay.com

And that led to even more part numbers (cheapest sold price found):

756413-003 ($7.45)
693711-001 ($7)
ADP-65HB HC ($7)
HU10104-8193
902990-001 ($7)
751889-001 ($6.10)

And many of the listings on these are obo, so an offer might also be accepted getting us into the $5 shipped range that I was talking about.

So with about the same time as soldering a resistor (far less time if you solder like me, haha), you can do some searches with part numbers and whatnot and find something that's cheap and still high quality.

 

[jer emy]

Question about serial console setup on this box: Is it possible to have serial setup on the T620 via USB? If so, what are the settings in the BIOS/OpnSense (if applicable)/type of cable you need?

I finally put the network rack on my wall and moved my router into it. I dont want to have to mount a monitor on the wall next to it just to get console for the firewall. I thought I had everything. I have a USB to RJ45 serial cable I use for network devices at work (FTDI chip) with an RJ45 to Serial dongle to connect to the lone serial port on the box of the router. No dice. Either I have the wrong cable or the wrong software setup.

Any help would be greatly appreciated!

 

[Samir]

I forgot about my friend over at parkytowers has a great deal of info on this thin client:

Specifications and hardware description for a HP t620 thin client

Hardware description of the HP t620 thin client

www.parkytowers.me.uk

I even forgot that I sent him some info from this thread, lol.

Modifications to a HP t620

Extending a HP t620 thin client

www.parkytowers.me.uk

 

[CIR-Engineering]

I forgot about my friend over at parkytowers has a great deal of info on this thin client:

Specifications and hardware description for a HP t620 thin client

Hardware description of the HP t620 thin client

www.parkytowers.me.uk

I even forgot that I sent him some info from this thread, lol.

Modifications to a HP t620

Extending a HP t620 thin client

www.parkytowers.me.uk

Man, I wish I had found this page before I had done my own work two weeks ago!

HP Thin Clients PSU

using non-hp PSU with HP thin client

www.parkytowers.me.uk

Sigh

 

[PaintChips]

Sigh

I always thought it was common knowledge about HP vs Dell power bricks. The other big difference is later gen HP power bricks support "rapid charge" using the smart pin, for example if you use the barrel connector adapter to smart pin with an old HP power brick some Thin Clients, Mini Desks/Elite Mini either won't boot or you'll get a BIOS power management error.