Howto, Repairs

DECSERVER 200 Fan Replacement

In case you have a DECSERVER 200 with old squeaky fans, and at the same time you’re wondering what to do with old CPU fans hanging off your pile of computer junk, consider this.

Recycle Old CPU fans – Replace Your DECSERVER 200 Ageing, Rumbling Fans

First of all, you will need to take your Decserver 200 apart – easy enough, just remove the four screws sitting holding the rubber feet.

Then, open the brass cage – four screws on each side must be released, as well as a couple on the top and the rear.

Release two screws and take out the bracket holding the two 80mm fans – it should look like this:

Original 80mm fans

My original fans were quality Comair-Rotron model ST12L6, Date coded 12-AUG-89, DEC part no. 1221125-07. They probably did a good 100000 hours before the bearings finally started going bad.

The fans are riveted in place. The rivets are not hard to remove using a small plyer or wire cutter.

Rivet

Next, remove the CPU fans from their original Pentium heatsinks, and chop off any protruding bits of plastic so you can mount them using cable ties. I didn’t worry about gaps or exact alignment with the original hole, as the two fans are probably an overkill for the Decserver anyway.

Intel fan - mounted using cable ties Intel fan - mounted using cable ties

Cut off the 3-pin connector from the CPU fans, and re-do the looms – the yellow wire goes to the original red wire (+12V), the black goes to the original black wire (Ground). Any other wires can be chopped off – they are not used. It should now look like this:

Intel fans mounted on bracket

Next, re-connect the bracket to the enclosure (2 screws),plug the two original connectors back into place, and your’e done.

Finished - viewed from above

Power up the Decserver 200, and make sure the fans work. Now you can enjoy a two-CPU acceptable noise level, instead of that horrible grinding rumble. It is also nice to see a 68000 Motorola CPU doing such a nice job after all these years, which is more than can be said about the Intel CPUs from which the fans were removed.

68000 on main board