Shock absorber replacement

Shock absorber replacement
Difficulty	Expert
Duration	60 minutes
For series	Some one-drum Z+Any machine released with or after the RZ line, i.e. RZ/RV/EZ/EV/SF/SE and MZ/ME/MF/MH machines. machines SE
Tools	JIS phillips #2 screwdriver Metric hex wrenches
Parts	046-15009 1 × Shock absorber 046-15008 1 × Shock absorber bracket (if not already installed)

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On some models of one-drum Z+Any machine released with or after the RZ line, i.e. RZ/RV/EZ/EV/SF/SE and MZ/ME/MF/MH machines. machines, a small black rubber shock absorber helps soften the impact of the pressure lever (used to move the pressure roller up and down for each rotation of the drum. Over time, the shock absorber wears down—when it is fully deteriorated the riso can no longer be used for printing. The symptoms of this issue are different depending on if the pressure roller is stuck in the up position or the down position.

• If the pressure roller is stuck in the down position, pages will feed partially into the riso, making it into the area above or just past the pressure roller, where they will halt and trigger a paper jam. These pages were never pressed onto the surface of the drum, so they will have no image printed on them.
• If the pressure roller is stuck in the up position, pages will come out over inked, with ink spread across the whole back of the sheet and continuous ghosting on the front. Furthermore the drum will be difficult or impossible to remove, as the pressure roller will be dragging against it as it is pulled out of the risograph.

The shock absorber can be replaced, but it is a difficult task which involves partially disassembling the main drive of the risograph, in the back of the machine.

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  A worn shock absorber (in its holder) and a new one. Often by the time of printing failure, there is little or nothing left of the rubber absorber itself.

Background

Not all one-drum Z+Any machine released with or after the RZ line, i.e. RZ/RV/EZ/EV/SF/SE and MZ/ME/MF/MH machines. machines use a shock absorber—all models do, as do some SE machines. Known models which use a shock absorber are as follows:

	EZ200	EZ201	EZ220	EZ221	EZ230	EZ231
	EZ300	EZ301	EZ330	EZ331	EZ370	EZ371
	EZ390	EZ391	EZ570	EZ571	EZ590	EZ591

	RZ970	RZ977	RZ990	RZ997	RZ1070	RZ1090

	SF9350	SF9450	SF9490

The presence of shock absorbers on EVSE machines is currently unknown/unconfirmed. Which models have them also needs verification.

Two versions of shock absorber

Older machines sometimes have an older model of shock absorber installed, which was adhered to a small rounded plate, rather than held within a mounting bracket, as the new ones are. These older shock absorbers are no longer available as replacement parts, however the new mounting bracket is interchangeable, after which the new shock absorbers can be used. If a machine does not have the mounting bracket (part no. 046-15008) it will need to be acquired along with the shock absorber (part no. 046-15009) before the repair can be made.

Confirming diagnosis

The easiest way to confirm the diagnosis of a deteriorated shock absorber is to look for the black rubber debris which will collect on the base plate in the back of the riso, beneath where the shock absorber is mounted. This can be seen just by removing the back cover of the risograph (4 screws) (though it is easier to see if the circuit board panels are opened up as well—by removing the screws marked with arrows on the brackets).

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  The back of the machine, with the area to check highlighted.

• 

  Rubber fragments from the damaged shock absorber.

Replacement procedure

First the riso must be setup so that access to shock absorber area is a little easier—then all work will be done with the riso off and unplugged. After replacement, proper calibration of the pressure lever should be checked.

Setting up the risograph

1. Turn the riso on in test mode.
2. Remove the drum and close the front door.
3. Get the machine into the main test mode area by pressing the STOP button until the numeric display reads 0 or 0000.
4. Run the pressure lever maintenance position test mode by punching in 908 + START and waiting for the test to end (about 5 seconds, will finish with a beep).
5. Turn the riso off and unplug it.

From this point forward, the riso should remain off and unplugged until the repair is finished and the machine is fully reassembled.