estudio 451c grainy copies

[digicor]

i have replaced the dv, ran al the adjustment services, i still have grainy copies, the copies from the blak alone are fine, nice density, the color's all of them are not dense at all, even the calibration sheets are not dense, spotty , or pixelated, i call it grainy.
this machine has 12 k on it, but it sat for over a year,.
any help on this , thanks.

[ToshibaTech]

Does the revolver unit have any play in it rotationally or latterly front to back in the machine? It should be very tight. Might not be your problem but this would only affect color copies. Did you clean the laser slit glass?

[michaelc]

I have had people knock the colour dev leaf plate out of position. It is situated on the left hand side where the EPU comes out. If it is damaged or deformed it can give you problems.

[ivovb]

Check/clean:
1. Main charger and grid.
2. All of the shafts in transfer belt unit.
and slitglas as ToshibaTech says previously.

BR

PS Which dv You are replaced?

[WOETC]

My first check would be the colour dev spring as michaelc says, also check the contacts on the bias contacts on the front of the dev spring. Another biggy for me has been where techs have taken out the process unit and ion replacing it not quite seated the hole in the front of the frame properly over the bearing of the revolver. That pushes the revolver slightly out of line.