Hi We'll Sign, do you still have this "!ERR-PEN" with your CG-45?
I found your post because i have the same plotter with the
same error. But today i solved this problem. For you and for
other users still working with this stone-age machine, here is
my solution. First pull out the screw from the pen cover.
Then unscrew the two golden screws from the upper side of
the pen-holder and lose the two golden screws from the lower
side of the pen-holder. After that you can get the whole pen-holder
away from the machine. At the bottom side of the pen-older is
a small PCB located. Pull out the two black screws. At the other
side of the PCB is an Optocoupler sending out IR-light to a little
mirror (5mm diameter) and receiving the reflected light.
Use a Q-Tip and alcohol to clean both the Optocoupler and the
reflector. Reassemble the whole thing in reverse order and power up
the machine. Now it should work fine again. I hope this will be
usefull for you or others with the same problem.
Please let me know if it helped.
Kind regards from germany
Friedhelm (FBCS)