Step 2
 
a
 
Perform the blank or white pages service check or missing 
color service check. See 
“Blank or white pages check” on 
page 41 
or 
“Missing color check” on page 58
.
 
b
 
Enter the Diagnostics menu, and then navigate to:
 
Printer setup 
> 
EP setup 
> 
Toner  patch sensor adjust  
c   
On the sensor gain characterization row, touch 
Start
.  
d 
On the sensor gain verification row, touch 
Start
.
 
e 
Check the graph in the printout.
 
This sample graph shows good values:
 
 
 
 
 
 
 
 
 
 
 
 
 
Note: 
The normal range of the sensor voltage is 1.5–2.0 volts.
 
 
Does the graph show good values?
 
Step 4
 
Check the TPS sled and TPS wiper mechanism for proper 
installation.
 
 
Are the TPS sled and TPS wiper mechanism properly installed?
 
Step 5
 
Reinstall, repair, or replace the TPS sled and TPS wiper mechanism. 
See 
“TPS sled removal” on page 364 
and 
“TPS wiper 
mechanism removal” on page 367
.
 
 
Does the problem remain?