HP Error 50 Service
A 50 service error indicates a problem with the fuser
assembly, this is the part of the printer that fuses (melts) the
toner into the media.
It consists of a heated roller or film and a pressure roller along
with drive gears and
sensors. It is subject to mechanical wear and thermal degradation.
Most newer models have solid state thin film heating elements rather than the
halogen lamps in older machines. These heating elements are subject
to failure from burned resistive heating paths and fractures of
the ceramic substrate material. There are typically two sensing
elements, a thermal fuse to prevent catastrophic overheating, and
a thermistor to provide feedback to the heating circuit and indicate
when to turn the heating current on or off. It is important that
replacement fusers use proven and tested replacement materials.
fusers use first quality replacement parts and ISO 9000 standards
in the remanufacturing process.
50 Service errors can also be related
to the power supply or control circuits.
the fuser is
a maintenance item
and the major component of a maintenance kit. You can Self maintain
your printer and save. Support
for our customers is always available via email and live chat.
Select Your Printer Model
Common To Most Newer HP Laserjet
HP LJ 8150 50.1 Fuser Error
HP LJ 4/4M and HP LJ 4+/4M+/5
HP Laserjet Printers
50.X FUSER ERROR alternates with
For help press ?
A fuser error has occurred.
1 - low fuser temperature
2 - fuser warm up service
3 - high fuser temperature, fuser over temperature
4 - faulty fuser
5 - Incorrect fuser installed
6 - Open fuser circuit
8 - low fuser temperature (subthermistor)
9 - high fuser temperature (subthermistor)
This error usually indicates a defective fuser. Turn
off printer for 20 minutes (to allow internal error circuit to reset)
If the error persists, it could be due to a faulty thermistor, fuser
heating element, or loose or open
to the fuser. Sudden occurrences are almost always the fuser assembly.
The fuser assembly may be hot, allow to cool before removing it from
the printer or injury may result. You can perform a heating element
test by checking the resistance between the two heavy leads in the
fuser connector. Resistance should read less than 100 ohms in most
cases, an open circuit indicates a defective fuser.
For low fuser temperature errors, check the smaller leads on the fuser
connector to measure the thermistor resistance. At room temperature,
you should read in the range of 50Kohms to 350Kohms at room temperature.
It should not be an open circuit nor should it appear as a short circuit.
In some cases this error can also be caused by a defective power supply
or faulty DC controller board, but
first. The most cost effective method of repair is to replace the fuser
assembly. Component parts are not readily available and fuser repair
can become involved. Also be aware that early replacement of consumable
fusers may require reset
Replacement fuser assemblies are available here- Fuser
Assemblies or it may be time to consider a Maintenance
contains the fuser assembly.
•HP LaserJet 8150 Error 50.1 Fuser Error
This error indicates a low temperature condition which we have found
this to be the low voltage power supply, part number
Check the fuser resistance first to confirm, but most times it will
require replacement of the low voltage power
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LJ 4/4M & HP
On the HP Laserjet 4/4M/4+/4M+, most suspect
is the halogen lamp. The thermal fuse and thermistor are also
of a 50 Service error. You can remove the fuser assembly from the printer
and measure the resistance of the lamp/thermal fuse circuit - it should
be less than five ohms. As these printers age, power supplies are becoming
more common as the cause of 50 Service Errors.
Measure between the two heavy gauge pins on the fuser assembly connector.
If you measure an open circuit, the problem is most probably the lamp.
Removal of the lamp, although not difficult, requires knowing where the
snaps are located to remove the plastic covers. When you purchase a lamp
we can email instructions.
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