Removing The Optical Paper Sensor; Printhead Resistance Codes - HP PageWriter XL M1705B Service Manual

Removing the Optical Paper Sensor.
Remove the optical paper sensor
as follows:
1. From the inside of the empty paper compartment, insert a small,
flat-bladed screwdriver into the square hole (see Figure 7-16) on
the surface of the plastic printhead housing.
2. Apply pressure, using the screwdriver to compress the clip that
holds the lens in place, and lift the lens out.
Note .I
h?
To remove the sensor on some units with a serial number perfix of
3023A, remove the printer from the top cover to gain access to the
sensor.
Replacing the Printhead
Use this procedure to replace the printhead assembly. This procedure
Assembly
applies to all units.
To replace the printhead:
1. Unpack the new printhead. Locate the manufacturer's label
behind the ESD brush fibers. Note the resistance code printed
in the upper-left quadrant of the manufacturer's label. You need
this code later in this procedure when you set the printhead
resistance selector on the CPU assembly. The code is a number
that corresponds to a range of printhead resistance, as listed in
the following table.
Table 7-1. Printhead Resistance Codes
Code Resistance
Code Resistance
00 535-550 R 08 G31-640 R
01 551-565 09 641-650
02 566-580
A G51-660
03 581-590
B
Ml-670
04 591-GO0 C G71-680
05 601-610
D G81-695
06 611-620
E 696-710
07 621-630
FF 711-725
2. Feed the power and data cables (and the ground wire on newer
units) into the cardiograph assembly as you lower the printhead
into position. Slide the printhead down into the printer well.
3. On PageWriters having a serial number prefix prior to 3208A,
feed the ground braids to the top chassis and fasten.
4. Push the leaf spring into its slots in the well.
5. Open the top cover assembly.
6. Connect the power and data cables and the ground wire to the
appropriate connectors on the CPU assembly.
Removal and Replacement 7-23