MX3100 only prints yellow

[sharpie]

Hello, I have a MX3100 that will only print yellow on every color page. Occasionally I will get C/M/Y on each end of the main scan for about an inch, black doesn't show up at all. I have changed all drums, developer and transfer belt on a pm last week. I swapped the laser unit with a 2600 on site and the problem stayed with the 3100. I swapped then the Mother board and no change. I reinstalled firmware. I don't currently have a MFP or PCU for a 3100. Has anyone seen this?

[clark]

You have 1 of three things that will do it. Check shutters and check transfer belt if it locking on to the drums and last but not least the charge unit has a short. I would try the first 2 things first.

[sharpie]

no charge would cause the page to be solid black, or whichever color. I have the shutter cheated open. If I change the color profile in 64-5 I get color on the test page, sometimes the center of the page is light or lacking cyan completely sometimes its good. I can see line spaces between the main scan write when there is fading color in the center, the edges look good.

[sharpie]

and if I lower the charge to 250v in SIM 8-2 I get background on the page for each color.

[clark]

No charge will make a blank copy. you need charge for copy. If you are adjusting setting and getting different thing you are looking a bad mfp board. Call hytec.

[sharpie]

No charge makes a black page, but thanks for the advice. Toner is attracted to ground and the charge units provide a high negative charge, laser brings it closer to ground where the developer bias pushes the toner to the drum, just for a quick lesson.

[clark]

ok. what ever. good luck. I didn't try to help you to get this lesson. I have been doing copier for over 33 years now. But you have all the answers so good luck.

[mickj]

Sharpie is correct on a digital machine which is what we are talking about no charge solid colour
for this fault can you add scans, as it sounds like shutters on laser I would remove them while testing to be Shure


now on a old analogue copier no charge would give you blank copies 33 years or not