U4-4 Error Message / Fuser Fails at Warm-up / Xerox Phaser 4500

 

Repair Advice for the Fuser Fails at Warm-up /U4-4 Error Message on the Xerox Phaser 4500

Probably the most common error codes associated with the Xerox Phaser 4500 series is the U4-2 and U4-4 Error Message. Both these errors are related to a fuser low temperature reading. In this article, I will discuss a few possible solutions for this error along with a few links to order a PM kit if needed. The PM kit comes with the fusing assembly, transfer roller, and several feed tires. Due to the price of the parts sold individually, the PM kit is well worth the value as it is inevitable you will have to replace these parts over time. The kit parts are rated at 200,000 prints and typically get replaced when the replace maintenance kit is displayed on the control panel.

Phaser 4500 U4-4 Error Message

XEROX Phaser 4500, 108R00600 Maintenance Kit (110V)

Phaser 4500 PM kit

 

Troubleshooting Tips for the U4-4 Error Message on the Phaser 4500 Series

1. Obviously turning the machine off and back on is the first step. It also wouldn’t hurt to check that the machine is plugged straight into a wall outlet and not on a power strip, battery back-up, or UPS. These devices can cause issues as these printers require a large amount of energy to get to the correct operating temperature. Unlike other heating devices the time it gets to these high temperatures is timed and failure to reach these timed goals is what causes these Fuser low temperature readings like the U4-2 and U4-4 Error Message.

2. The next thing I would check is the fusing assembly itself. For low temperature readings like the U4-4 Error Message from the start I always check the thermostats. Below in the picture the thermostats are the two round pieces under number 2. When the thermostat is open AC power fails to run through the fusing assembly and it fails to heat up. To check the thermostat you need to check for continuity across the two thermostats together and individually, they should have continuity through them meaning they are closed and AC power can run through them, much like a fuse. Typically only one of them opens. The thermostats are meant to open when they overheat and close when they cool back down. Often times they fail to close back up. If you find this to be the case then take a can of compressed air, hold it upside down, and give the open thermostat a blast of extremely cold air. Now check the thermostat again. If it is closed you will have continuity and you can put it back in the machine and try again.

3. Check the thermistors. The thermistors are the sensors inside the fusing assembly that measure the temperature. Dirty thermistors can result in low temperature errors. The thermistors are number 4 in the picture below. Remove the thermistors and check to make sure the surface that comes in contact with the hot roller are clean of debris. Gently clean them off and re-install them in the unit. Check the machine again.

Phaser 4500 fuser electrics

4. Replace the fusing assembly. See the Fuser removal instructions below and check out the links for buying options.

Click on the link below for the Maintenance Kit replacement Instructions along with the Fusing Assembly

Replace Maintenance Kit Message on the Xerox Phaser 4500 Printer

Click on the link below for additional details and buying options for the Phaser 4500 PM Kit
XEROX 108R00600 maintenance kit (110V) for xerox phaser 4500

Xerox 108R00600 Phaser 4500 Maintenance Kit in Retail Packaging

Price: $189.62

1 used & new available from $189.62

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