HP Pro 4300 C9H70UT C9H70UT#ABA Black, Replace the laser/scanner assembly. See Laser/scanner

Table 72. Black page

Possible cause	Recommended action(s)
The print cartridge is defective.	● Replace the print cartridge.
The high-voltage connector springs are	● The high-voltage connectors protrude into the print cartridge
dirty or damaged.	cavity. Clean the springs if they are dirty. Replace the springs if
	they are damaged or missing.
The laser beam drive circuit or	1. Check the cables between the DC controller PCA and the
high-voltage circuit is defective (it is not	high-voltage circuitry (part of the power supply).
supplying the correct voltage).	2. Replace the power supply. See “Power supply” on
	page 188.
	3. Replace the DC controller PCA. See “DC controller PCA” on
	page 181.
The laser/scanner assembly is defective	● Replace the laser/scanner assembly. See “Laser/scanner
(it is turning the laser beam on	assembly” on page 173.
continuously).
Connectors between the laser/scanner	● Inspect and reseat the connectors. If necessary, replace the
assembly and the DC controller PCA	cables.
are not seated correctly or are defective.

322 Troubleshooting Q2431-90912