Hello Paul.
I suggest that you verify the condition of the "Back-up
Battery", which is located within the front panel/face plate of the
radio.

I suspect that if the battery leaks onto the surrounding circuit areas,
a huge amount
of proverbial "hate & discontent" could take place with regards to
proper operation of the "450S" radio.

One internet page I DO know of which presents satisfactory images &
instructions for inspecting & removal/replacement of the back-up
battery is located at the following URL:

http://www.geocities.com/lfnca/450ba...at_battery.htm

Additionally, there are several Yahoo Groups available which offer
multitudes of solutions issues related to Kenwood Amateur Radio
products. One related directly to the "450" {in addition to the "850" &
"690"} can be found at:

http://groups.yahoo.com/group/TS-850_450_690/

You'll find many fine people within the "850/450/690" group who would
probably come through with some additional suggestions/solutions.

Good luck, 73

Mike

Semper Fi / CV-41 / VMCJ-1