GNS 430 Freq Window is AWOL

[Toobuilder]

All,

My GNS 430 is acting funny. Sometimes, it will boot with the VLOC frequencies displayed in the upper left block with no COMM frequency block visible. Pressing either the VLOC or COMM flip flop will activate the freq change on the VLOC window, but will not bring the COMM window into view. Trying to toggle the cursor between the VLOC and COMM also fails to bring COMM back as well. As a ?fix?, I can recycle power several times and the COMM block will eventually appear as normal. However, sometimes it will appear with 121.5 in the active window (instead of my last used freq). Retuning is as normal, but sometimes it will not transmit (no RX indicator, and no side tone). The next day it will function fine?

Any ideas?

[BobTurner]

I think the emergency frequency appearing may be a symptom that the internal battery needs replacing (nominal lifetime around 7 years). But the other symptoms have me stumped. I'm afraid a trip to the shop is in order.

[Toobuilder]

Well, I'd say this unit is closing in on the 7 years in service, but there has been no "low bat" message yet.