Banding on QSS-34Pro

[forrest]

We bought the "refurbished" qss-34 a few months ago and it seems to have one problem after another. I have a light banding that is progressively getting worse on prints coming off of it. The banding is on the leading edge of the prints as they come off of the printer and then dissipate. The light banding has been there since we got it. I've tried everything the people we got it from have said to do to fix it, such as the Paper pressure operation correction but to no avail. There was also a darker more solid black banding line that ended up being fixed when they sent us a replacement exposure drive/advance unit. However the light banding has never gone away, and recently has started to get worse. Any suggestions for what could be causing this problem or for a possible fix? I've attached two samples of the banding. Thanks for any help!

[yustas]

I think you need to check:

- the quality of "ground". Sometimes the absence or poor quality if it may be a cause of banding.

- check all gears and bearings in paper advance unit for wear

- check the condition of power supply unit.

The quality of stable voltage is important.

 

If you find the cause, do not forget to inform us.

[forrest]

Checked the ground and power supply/voltage. All that is good and does not seem to be the source of the problem

[yustas]

Please make a gray test and scan with 600 dpi. Then place it to any fil exchange server to look at it as close as possible.
Show the paper movements direction on the test please.

[forrest]

https://wetransfer.com/downloads/69231b9f7c3e937ce67b5955ea11cbc320170404184428/7e9bb0c2b58c7b5bf8cbfb411db2052720170404184428/d1fbe8?utm_campaign=WT_email_tracking&utm_content=general&utm_medium=download_button&utm_source=notify_recipient_email

 

gray test is here

Edited April 4, 2017 by forrest

[yustas]

We inspected the scan.

This sort of banding has no attitude to power supply unit's problem or ground.
It seems some sort of vibration makes an effect on laser unit during the start of exposure (a few moving parts [like arms] are in use at this time).
Pease try to print the picture with open front door and a top cover (use magnets to cheat the lb's brains). 

Placing your hand on the laser unit try to catch the moment of the start of vibration.

Maybe the laser unit has a problem with fixation? Check all screws and damping resin under them.