Tip Computer - 1990 XJS Coupe, 88:88

Hello,

After taking my 1990 XJS Coupe V12 to the mechanic for new plugs, wires, distributer cap, fuel and radiator hoses... The Trip computer displays 88:88. I tried to reset it, but it doesn't fix it. I don't think the battery was disconnected because the radio DID NOT need to be recoded.

Any ideas on what may be wrong with the Trip Computer?

Thank you,

Mike Moore
1990 XJS Coupe
Tampa, Florida, USA