[TenTec] Display problem on 544

[Winston]

I have a Ten Tec 544 (digital Triton 4). The frequency display on 40 meters has gone crazy, throwing up random numbers on all digits, constantly changing, even when not tuning. It tunes in stations but display keeps running crazy, not responding to tuning. All other bands OK.
Anybody have an idea what could be wrong?
It started doing this very randomly about a month ago. However, it would stop when I quickly changed the bandswitch back and forth between bands. Now that doesn't stop it. Continuously running crazy now. 

Any ideas appreciated.

73, Winston K4CWQ

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