[1000mp] FP 29 Servie

[Mike Schatzberg]

This message is posted for Bruce, who
can't seem to post.....

After reading about FP-29 failures due to dust collection inside the unit causing shorts on the PC board, I decided to clean my supply. I found it to be very dusty dirty. I am sure there are several ways to clean the supply, the following approach seemed to work well for me. 


Obtain a fresh can of "Air Duster" or equivalent with a 4-5 inch extension tube. This product is usually available at Radio Shack, a camera store or computer store. Also obtain 4-5 cotton swabs and some denatured or isopropyl alcohol. Clear a well lighted place to work.


Turn off the supply and unplug it at the AC wall plug. Then remove the AC cord at the supply. 


Note that to remove the DC power cord that runs to the Mark V, you need to depress the small clip on the flat outside edge of the supply connector. This will release the little finger on the power cord connector that snaps in place when you mate the connectors.


Inspect the supply from the outside. If the small blower on the bottom has collected considerable dust, the supply needs cleaning. You cannot clean the supply properly through the blower opening. I did not remove the blower guard or blower.


To remove the supply cover, remove 8 black screws and 2 unpainted screws from the cover using a small phillips head screw driver. Note the location of the 2 unpainted screws. They will tell you which way to replace the cover. The cover will then slide up and off.


At this point, use the Air Duster to remove most on the "loose dust". If typical, significant dust will remain on the blower. Working from both sides of the supply, use swabs damp with alcohol to carefully clean the blower blades and housing.


The failures mentioned earlier, were apparently caused by dust between the internal aluminum chassis and the circuit PC board. To clean this area, it is not necessary to remove the PC board. Carefully remove the 4 black screws from the outside bottom of the supply. You can now tilt up each end of PC board/chassis assembly. Slide the Air Duster extension tube into the space between the chassis and PCB and blow out the collected dust. Slide the tube in and out, up and down, to remove as much dust as possible. Do this on each end.


Being careful to not pinch any wires, replace the 4 black screws, on the bottom of the supply, that hold the chassis/PCB assembly in place.


Now clean the inside of the cover to remove all collected dust. Inspect the supply assembly to be sure it all looks OK. Blow out the assembly one more time with the Air Duster and replace the cover. Be sure to install the cover with the two holes, for the unpainted screws, in the correct location next to the two brackets. Be sure the cover sits on the ridge of the front panel. Check to see that the cover does not pinch any wires and then replace all cover screws.


73

Good luck

Bruce AA4Z