HP T5720: Linux 




Mounting a CF card

In April 2016 I had an email from Jim who was about to do the hard drive mod described below. Up to now he had been using a CF card. He had mounted the card and reader on the inside of the cover.

t5720 Compact Flash card mounting "Two bolts are secured to the casing with a single nut each. The adaptor then sits on those nuts secured by two further nuts locked together on each side. A square of duck tape underneath prevents any potential shorting. The CF card is running a LAMP web server using the final version of Crunchbang."

Adding a Hard Drive

In February 2016 I received an email from Rich Hawley describing his approach to adding a hard drive to the t5720. There is little space internally to fit a drive and his solution I think is rather neat.

The first thing to note is that with the t5720 the cover arrangement is a little different to other HP thin clients. With those you slide off the outer plastic cover and then have to undo (usually) five screws to remove the internal metal screening cover.

With the t5720 the plastic cover is fixed to the internal metal screening cover and both slide off together. In addition, for a reason I'm not sure about, the centre of the cover that carries the HP logo has another square also carrying the logo plugged into it.

t5720 slot on pop-off cover


You can see the additional cover in place and a handy slot to let you pop it off with a flat-bladed screwdriver.

t5720 popped off cover

t5720 mounted hard drive


Rich's solution is to remove the second square and mount the hard drive where it was.

t5720 hard drive cable slot


He then cut a slot in the cover for the ribbon cable to run through to the IDE connector.

t5720 hard drive covered


Finally, using four 6mm stand-off pillars, he remounted the smaller square over the hard drive.

The result is quite a visually neat solution with the added benefit of reasonable air circulation around the hard drive - assuming you're using the t5720 in a vertical orientation.

Possibly how not to add a Hard Drive

In August 2021 I had an email from a reader who had followed a guide from 2012 on adding a hard drive to a t5720. Essentially this involved:

Hard Drive mounted on t5720 ...mounting the drive on the inside of metal screening cover and placing it so it is over the heatsink that's cooling the support chipset.

t5720 trimmed heatsink ...then trimming the fins on that heatsink so that there is space for the drive when the cover is replaced. Here I believe about 5mm(?) has been removed so that the fins are now the same height as the mounting screws.

t5720 trimmed heatsink comparison A before (lhs) and after (rhs) comparison so you can see that a sizeable volume of cooling fins have been removed.

(Doing my best with existing photos. Hopefully you get the idea).

My correspondent went on to say:

"The chipset on that unit now gets way hotter than the CPU and in doing so results in system instability. I learned that the hard way. After 2-3 days with the degraded cooling in place the USB controller just stopped working until I shut down the device and let it cool down."

This is a salutary lesson in the need to think through any side effects of your proposed modification(s). Heat dissipation in fanless thin clients is very reliant on adequate passive heat sinking and good ventilation as there are no fans to force a generous amount of air through the unit and over the heat sinks.

Any modification that reduces the passive cooling, restricts air circulation or adds a significant heat source erodes the design margins and may lead to system instability. Note the 'may' as your local environment (eg: typical room temperature) and where/how your thin client is placed also plays a part.


Any comments? email me. Added February 2016    Last update August 2021