MP C4503 Magenta Lines

[Lagonda]

I have a feeling I should know the answer to this one but for the life of me I can't remember it. Getting very fine magenta lines in main scan direction. they appear randomly across the page at no regular pitch. The strange bit is that when the line crosses a block of colour it disappears and gives a void where the magenta should be as parts of the colour mix.
My money is on a problem with the laser but the field tech says he's changed the laser unit along with the magenta PCDU, ITB unit HV board and IPU board.
What have I forgotten?

Samples are long edge feed.

Sample 1.jpgSample 2.jpg

[aAandy]

Re: MP C4503 Magenta Lines

stick the slit glass cleaner in the magenta slot & run a print, if it's a HVT leakage problem the lines should remain, if it's a laser problem they should vanish along with all magenta print

could be as simple as poor drum ground, or arced plastic HVT bits

[Lagonda]

Re: MP C4503 Magenta Lines

stick the slit glass cleaner in the magenta slot & run a print, if it's a HVT leakage problem the lines should remain, if it's a laser problem they should vanish along with all magenta print

could be as simple as poor drum ground, or arced plastic HVT bits

Thanks for the fast reply Andy, but surely if it was a dirty slit glass the lines would be in sub scan not main scan? However do like the idea of poor drum earth.

[aAandy]

Re: MP C4503 Magenta Lines

Thanks for the fast reply Andy, but surely if it was a dirty slit glass the lines would be in sub scan not main scan? However do like the idea of poor drum earth.

i meant to leave the cleaner in the magenta slit-glass slot while you print, to use it as a shield to block the magenta laser beam

that will eliminate the laser entirely and leave you with either HVT leakage or poor drum ground

[Lagonda]

Re: MP C4503 Magenta Lines

i meant to leave the cleaner in the magenta slit-glass slot while you print, to use it as a shield to block the magenta laser beam

that will eliminate the laser entirely and leave you with either HVT leakage or poor drum ground

Ah it all comes clear now! Thats a neat trick, never thought of that one before. Proves you can teach ancient dogs new tricks.

[davel]

Re: MP C4503 Magenta Lines

Won't you just get solid magenta print.

[slimslob]

Re: MP C4503 Magenta Lines

Won't you just get solid magenta print.

No. Ricoh uses write to no charge. Blocking the laser prevents it from erasing charge from the drum therefore the entire drum remains at full charge.

[copier tech]

Re: MP C4503 Magenta Lines

Check that the rear cover is on the back of the PCDU, leaving this off gives this kind of copy quality issue.

[Mark Bbb]

Re: MP C4503 Magenta Lines

The only thing i can see from here is a wrong instruction to write lines.
So the IPU might be defect.

If you convert the magenta color to cyaan, is it still the same?

[aAandy]

Re: MP C4503 Magenta Lines

Won't you just get solid magenta print.

you'd think so,,, and rightly (was waiting for someone to ask that question)

someone beat me to the answer though

[davel]

Re: MP C4503 Magenta Lines

Yes, my mistake.

[Mark Bbb]

Re: MP C4503 Magenta Lines

Hello,
so, what was the outcome?

[Lagonda]

Re: MP C4503 Magenta Lines

Hello,
so, what was the outcome?

No resolution as yet, winter flu has struck and we're 4 techs short so haven't been able to get back there to do some serious fault finding.

[slimslob]

Re: MP C4503 Magenta Lines

No resolution as yet, winter flu has struck and we're 4 techs short so haven't been able to get back there to do some serious fault finding.

Hope you haven't been bitten by that flu bug.

[BLADE]

Re: MP C4503 Magenta Lines

I have seen fine lines like that in half tones, in feed direction , are you sure about the orientation. Polishing drum fixed mine.