No black on colour prints and colour test page on ricoh mpc4503

[Pixtech Frameworks]

You have to loosen the controller box and swing it out and then you'll see this red marked PCB.
Once you get there you can't really miss it.

I have swapped part with an old machine part, problem still the same

[luca72]

I have swapped part with an old machine part, problem still the same

if you try to turn with finger the black developer unit rear gear , the magnetic roller turn?

[Codex]

+1 for BK development unit, some worn out gear, the motor turns normally , but the magnetic roller doesnt turn.

[Pixtech Frameworks]

if you try to turn with finger the black developer unit rear gear , the magnetic roller turn?

It turns perfectly.

[Pixtech Frameworks]

+1 for BK development unit, some worn out gear, the motor turns normally , but the magnetic roller doesnt turn.

I have swapped PCDU still the same no black

[Polo-022]

Laser Unit synchronization maybe! I have seen that sometimes back in the days of MP C2500.
It recovered itself somehow...

[Pixtech Frameworks]

Laser Unit synchronization maybe! I have seen that sometimes back in the days of MP C2500.
It recovered itself somehow...

I was thinking so too. Maybe laser unit, I don't have it 4503/5503/6003 to interchange. Only have 3003/3503 which isn't the same.

[tonerhead]

I must be missing something here. If you print a black/white only does it work or is it blank? Black is the anchor for alignment and everything. It should be coding if black is not working.
If you do a black/white skyshot and interrupt the copy, pull the itb and black pcdu, what do you see?

[Pixtech Frameworks]

I must be missing something here. If you print a black/white only does it work or is it blank? Black is the anchor for alignment and everything. It should be coding if black is not working.
If you do a black/white skyshot and interrupt the copy, pull the itb and black pcdu, what do you see?

Print/copy on black is blank. Even interrupting the copy no traces on ITB everything blank.

[slimslob]

Have you checked the K laser shield glass? If it is covered its entire length with dust or toner you will get no write.