This error is down to a high voltage leak on a corona wire unit arcing. Generally you can clean the unit but in quite a few cases you have to replace the plastic end blocks on the corona unit. The unit sits just under the drum and can be slid out when you push the green handle in the middle of the copier to the left. There is then a black square looking piece of plastic that drops down. If you push it down slightly and pull it towards you it will slide out. Use a paintbrush to dust it off and see if that makes a difference. I sent about 6 years working on these particular machines so if you need any more help just ask.
Monkeys Lips, August 2008