Mark V







Mark V Brightness Modification


If you would like to improve the brightness of the display this is how you can do it. On the inverter board, there is an 18 OHM 1 Watt resister. ( R3502 ). Replace this resister with either two 10 Ohm 1/2 Watt resisters, in parallel, or one 5 Ohm 1 Watt resister. The result will be as follows. Hi will be brighter, but not too bright. A more pleasant looking display. DO NOT jumper the resister as you can cause components to fail on the display board from over heating. Note if you use a single 1 watt resister, the leads will be too large for the holes, suggest that you cut out the old resister and solder the new resister to the leads. Otherwise you will have to enlarge the holes. The resisters that I used were RadioShack 10 ohm's. Which fit nicely.. Once the display is warmed up I can now easily see it across the room as well in sunlight conditions.


TIPs:  If you ever have a problem with the display, check these items first. A. R3502 B. Fuse F3501 C. Thermo fuse F3502. D. Make sure there is 13v at pin 2 of J3501, if not, the problem is on the display board. This should work on the MP & Field.. If some one has the schematics copied of the field scanned into the computer, please Email them to me ......

The original resister drops the 13V dc down to about 10V dc. The new resisters will only drop the voltage to about 12V dc.... There are NO heating issues from this mod. ONLY a much better display...I make NO guarantee with this mod, do it at your own risk..

73's John KC3QL




This site was last updated 08/27/07