HP M479 contrast problem

[Tricky]

Re: HP M479 contrast problem

You need to google "hp 477 repair manual" the first result from Laser Bros.
Its basically the same machine.

[Profibastler]

Re: HP M479 contrast problem

How to disassembly the detect sensor, please?
Can`t find anything about in SM.
It`s built into the ITB?
No error codes occured.

You need to google "hp 477 repair manual" the first result from Laser Bros.
Its basically the same machine.

[Crowfeather]

Re: HP M479 contrast problem

Sounds more likely that the internal assemblies are not sufficiently pressurized. This can occur if the chasis is bent (damage in transit), or if the assemblies on the rear door are not properly positioned. You can also get this if the toner tray is not railed properly.

You can get an output report for the CTD sensor in the service mode normally. If manually performing a calibration resolves the problem, then the fault will be with the toner cartridges or the CTD, but there's a difference between half tone and full tone calibrations.

You should really just perform a jam test as that will tell you whether there is a transfer or creation problem. if its a transfer problem you will see a full image on the imaging units, if its a creation problem then that wil be patchy.

[JtechC]

Re: HP M479 contrast problem

Perform a stop test while the paper is under the cartridges. Inspect the image.

[Profibastler]

Re: HP M479 contrast problem

@JTechC

How to disassembly the detect sensor, please?
Can`t find anything about in SM.
It`s built into the ITB?

I would swap cartridges one at a time to see if the issue changes.
If no changes, swap the transfer belt.
if no changes, I'd swap the density detect sensor. rc4-3728

Are there any error codes?

[Tricky]

Re: HP M479 contrast problem

@JTechC

How to disassembly the detect sensor, please?
Can`t find anything about in SM.
It`s built into the ITB?

You have said the same thing three times now, look for the repair manual and no the detect sensor is not part of the belt its the silver piece between the front door and the transfer belt.

aabelt.jpg

[JtechC]

Re: HP M479 contrast problem

@JTechC

How to disassembly the detect sensor, please?
Can`t find anything about in SM.
It`s built into the ITB?

It's in the service manual. I forgot the page right now.
You have to remove the cartridge tray and the ITB to get access to it.

Are there any error codes that can be visibly read from the service page?

[Profibastler]

Re: HP M479 contrast problem

You were right. Density sensor was dirty, because printer is a smoking device.
Thanks a lot

I would swap cartridges one at a time to see if the issue changes.
If no changes, swap the transfer belt.
if no changes, I'd swap the density detect sensor. rc4-3728

Are there any error codes?