HP Microservers are a low cost, small form factor cube-sh PC that are great for using as media centres or NAS boxes. I’ve already got a few microservers running FreeNas or Ubuntu server providing shared network drives or running as mass-backup boxes. Since this microserver was broken and relatively low cost, my first action was to investigate what’d gone wrong with it.

Amber power light: Failed PSU

When connected to the mains, the server’s power button was constant amber. It didn’t respond to button presses and wouldn’t power up. I did some research and it suggested that the most likely reason for the amber light was a stuck power button. I pulled the power switch connector from the mother board and used a multimetre on continuity test mode to check each pin pair until I found one that connected when the button was pressed. This indicated that the power switch was working fine, as it would complete a circuit when held down, and disconnect when released. I shorted the matching pins on the mother board, effectively becoming the power switch and the server still didn’t boot, which confirmed that this was not the problem. Delving deeper, I started dismantling the microserver to see if I could work out what had gone wrong – sure enough a quick visual inspection found the CD drive SATA power connector was a melted mess, and scorch marks were on the metal frame. The CD drive was dead, pins on the molex to SATA adapter having shorted inside the plastic housing. I pulled the PSU and found it to  be dead, it wouldn’t turn on when shorting the pins on the ATX header so a new power supply was in order.

Since HP microserver power supplies are quite expensive (~70 GBP), I wanted to make sure the motherboard still worked before paying for a replacement PSU. I used an old ATX power supply which I had floating around and connected it to the microserver. It’d never fit inside the case, so I just left it hanging around next to the microserver. It booted off a memory stick fine, and that was proof enough for me that I needed a new power supply.

I ended up finding this blog: http://chrisstark.co/2013/08/hp-microserver-n36-replacement-power-supply-psu/ which was someone in a similar position to me. They had a microserver which needed a new power supply, but found that LinITX had a similar replacement unit which was significantly cheaper than a genuine spare. LinITX is a fantastic site dedicated to embedded hardware and I’ve often browsed wishing I had enough cash to buy goodies from them. In this case, since the PSU was only £30 (GBP) I bought one straight away. This is a link to the PSU https://linitx.com/product/fsp-150w-1u-compact-power-supply-fsp15050gub/13062 and the quickfind code is FSP150-50GUB.

All back-plane cables are grouped by colour into a chocbloc, then a female molex cable attached to the other side.

With the PSU connected, the only problem I now had was the SATA backplane requires 4 molex power connectors and the PSU only has one. Since this is likely going to be a “toy” microserver due to the cost and not-properly-tested nature of it, instead of investing in molex splitters, I decided to hack off the existnig backplane molex cables, group the connectors into colours, strip the ends and solder them together. Once this was done I used standard electrical choc blocks to connect one end into a standard molex female that I’d cut off previously. It looks messy but is reasonably electrically sound.

Case Mods

Now that’s done, I decided to have some fun. I’ve had an air brush for years and never properly gotten into it – mastering a skill takes time which I’ve never seemed to have. Plus it’s messy so you’ve got to have dedicated time to flush through cleaner when you’re done, and set up a dirty work area. While tempted to companion cube my micro server I decided in the end to just do black and yellow hazard lines. First off, I opened the door and lifted it slightly to release it from the hinge. I was then able to use a pair of pliers to remove the locking mechanism’s nut on the inside of the door and put this to one side for safety. Once the lock is off (this can take some slight wiggling of the lock cylendar) I was able to unclip the plastic from the back metal frame. I only wanted to paint the plastic, and was worried there would be ghosting effects if I left the metal frame inside the door. I masked off the area using masking tape, following the lines of the air holes on the door. I mixed by yellow paint 50/50 with water and tried to evenly coat the door. That didn’t go so well. After 2 coats I gave up and instead removed the masking tape. I then got out some aluminium paint and dry-brushed the edges of the door to give it a weathered look. My method for dry-brushing, since I’d never done it before, was to get a little bit of paint onto a dry paint brush, dab it on my cardboard floor covering to thin it out, and then lightly brush the edges of the door. It actually came out really well – yes I am surprised by that! Finally I reassembled the server with the new door, power supply and hacked molex connector. I still have plans for what to do with the CD drive bay – possibly an LCD screen indicating IP address and drive status, I might replace the lock with a handle of some kind and I may paint the rest of the server. I also need to decide what to install on it!

Almost there – Microserver with new PSU, hacked back-plane power connector and painted front door.