KM-1650 inverted copies

[Nathanthea]

I have a KM-1650 which produces an inverted copy ( black background but the text is white) sometimes blank copy. I've cleaned the transfer ground connection and main charger but nothing happens.

Guys help me to figure out this problem. Do I need to replace something?

Thanks in advance.

[blackcat4866]

What happens when you print a counter page, or other internal print? =^..^=

[Nathanthea]

blackcat same thing happens when you use the back to back. The output is the same inverted copy. This copier used for copying only.

Any ideas are welcome .. thanks..................