Konica 7040 Error F-28-1

[Rigger]

Howdy!
I'm working on a Konica 7040 with 489,000 copies on it. It gets an error F-28-1 but the customer says they can run about a thousand copies before it does it again. My "Intravia" book says "Charge Corona" trouble but of course doesn't recommend any fix. Any clues as to what exactly to due to make this stay away would be greatly appreciated!

[Luther]

intrivia is telling you its a charge corona problem, easiest thing to do is replace the wire and the grid and go from there