Hp color 3700 light printouts

[Karamap]

Hi,
I have a hp3700 with light printouts.
I've upgrade the firmware, install new toners and have this parts on hand
DC controller, HVPS and color mis-reg sensor assy.

Is there anything else i could try or check prior to replacing the above parts.

Thanks in advance.

[MichaelTech]

Check all the contacts for the toners, and the imaging belt. Left side toner contacts should all be bowed out. If okay, the HVPS would be the next step.
Try another image unit .