Printer Fan Installation
by Guy Cousineau
Start by unplugging the printer and moving it to a comfortable working area. Turn it upside down and remove the deep inset screws at the edge of the printer. These are the ones that hold the cover in place. Carefully turn the printer over and remove the upper shell. Watch for the sleeve that fits over the paper tension guide; be sure it does not fall inside.
Your fan will be installed on the left side at the back of the printer. Not only is there sufficient room there, but it is the main source of heat. Cut away the pedestal on the left side (not the back) to make it level with the rest of the casing. Although a bit smelly, I used an electric soldering iron to melt it down; it was less trouble than trying to reach in with a file. Next remove the screw that holds the corresponding pedestal in the upper shell. The ridges in the shell must also be smoothed down to ensure a proper fit.
The next step is to find power for your fan. This entails the removal of the power supply and logic board: not for the faint hearted. You will find two screws at the back of the printer near the spot where the cords come in. Near the center of the printer (underneath the print head), you will find yet another mounting screw. On the under side of the printer, there are four more screws. These are the ones nearest the center of the printer. Mine were mounted on a metal bar (for added sturdiness?). It is recommended to tilt the printer slightly during this process rather than turning it over.
Now look at the front of the logic board. The part to the right and under the print head. There is a connector on the extreme right edge and a strip of connectors to the left. Take note of the colors and number of wires in each connector and gently pull each one out. On top of the heat sink at the back, you will likely find a ground wire running from the solenoid that advances the platen. Remove the screw and push the wire out of the way. Working from the back of the printer, lift the power supply slightly to clear the lip and begin edging it out. Watch that none of the wires or components get caught anywhere and pull gently. If it seems stuck, have a good look around. Perhaps you forgot to remove one screw?
Turn the power supply over to reveal a metal shielding over the power leads. Remove this shield and examine the wires. You will see that one of the wires from the POWER source goes directly to a connector and that the other is re-routed to the switch. Use the return wire from the switch and the other main power wire as your source for fan power. Strip a short bit of wire from the fan and solder it over the existing wires. Be sure to get a good connection. Then channel the wires towards the edge of the card and tie them down.
Although you can use electric tape, I prefer HOT GLUE as it gives a more secure bond. Before proceeding, you may wish to verify that the fan indeed has power. Check to make sure you have no possible short circuits and plug the printer back in. Turn on the power and check the fan. Be sure to UNPLUG the printer afterwards.
Replace the shielding and re-insert the power supply back in the printer. Re-insertion is trickier than removal. You must watch out for the cable that runs to the solenoid at the back. Once the board is in place, make sure that the said cable does not interfere with the print head movement. Try sliding it back and forth to make sure there are no obstructions. Replace the 7 screws holding the power supply. Insert each screw only part way until they are all in. This will allow minor adjustments to line up the holes. Be sure to tighten everything back up after. Then re-insert the connectors on the logic board... IN THE RIGHT SEQUENCE!
At this stage, you may wish to verify that the printer appears to be working correctly by plugging it in again. Make sure the fan is not in the way before doing so. If it whirs as it normally does on power up, you are probably ok. While you are there, you may wish to clean the knife switch on the left side of the front of the printer.
The next step is to decide on the exact location of the fan. I centered mine between the two ridges on the casing. I then made a template form a piece of cardboard with the four holes from the fan. With the fan mounted in place, I lined up the top two holes and marked the location of the bottom two. I drilled holes in the bottom of the casing, of the size of my screws. Because the printer cover is angled, I wanted to recess the fan a bit inside, so I used two large rubber faucet washers as spacers.
I then attached the fan to the bottom part of the casing. Then I placed the cover over the printer and, using the template, I marked the outline of the fan on the upper part of the casing. I then made a jig for my router and used a 1/8 bit to trace HORIZONTAL GROOVES in the casing. Although the lines were not perfectly straight, I thought it more frugal and neater than paying another two bucks for a finger guard. I then placed the cover back on again and refastened the whole thing together. I had two screws leftover: one that held the inner pedestal and one that attached the cover to said pedestal. If you have any more leftover, look things over again!
If you prefer to use a finger guard to the messy router approach, use the finger guard as a template to mark your first two holes on the bottom. Once those are drilled, replace the cover TIGHTLY and use the finger guard again to mark the top two holes. Using the finger guard, you can probably easily locate the center of the HOLE and mark it. You can then use a compass, or the finger guard itself (if it has round rings) to outline the circumference of the hole. Then make your cutout: be sure not to make it too large or you will break off the mounting holes to hold the whole thing together.
Although you may wish to try with a HOLE CUTTER, I prefer the coping saw approach, followed by a round file for trimming. Then, mount the finger guard on the outside and place the bottom two screws. Replace the top shell of the printer, being careful to sandwich it properly between the fan and the finger guard. Attach the top two screws and the bottom screws (now seven) which hold the upper shell in place.