Sharp AR-M460N photocopier has a black print error

[John]

I have a Sharp AR-M460N photocopier with black printout as shown in the photo. After cleaning the drum unit, it was white, but after a few pages, it turned black again. One day it was completely black, the next day it was a little white again. I took 3 photos and printed them on 3 different days. I suspect it's high voltage, but this item is expensive and you can't return it. I'd like to ask you guys to diagnose the problem for me. Thank you.

 

[Venessa]

If cleaning the high pressure doesn't fix this error, replace the components, replace the drum unit...
This error is usually due to high pressure, power source.

 

[Evelyn]

Is this power source expensive?

 

[Bridget]

Remove the drum unit to clean it, clean the high voltage drum, the high voltage next to the black charging shaft...

 

[Seraphina]

I've cleaned it all. It's a little clearer

 

[Jocelyn]

So you have to contact the big guys who specialize in Sharp products to borrow to test, because this product is rare and the price is a bit high because few people use it