Re: HP LaserJet 8100/8150 Low Voltage Power Repair

SMPS (switch-mode power supplies). The SMPS will usually supply other
voltages not just the 24V to the fuser, however all supplies coming
from the switch-mode transformer ought to be contain fuses, in other
words check the fuses first, theses could be transistor looking types
called IC protectors, they could be glass or ceramic tubular types or
even a low vaue metal film fusible resistor.

If other voltages are there then you can be pretty certain that the
SMPS is working, you will need a test meter and have some basic
knowledge, prior to rectification from the 'chopper transformer' the
voltage will be around 18 KHz AC not the usual 50 or 60 Hz mains
power frequency and will prove difficult to measure on most basic
test meters, the DC side after rectification is easily measured.

Any electrolytic capacitors with gunge coming from them or swollen
tops are easily seen and could also be the cause.

The fuser is a heater is the fuser element intact, again this could
esily be tested with an 'El cheapo' test meter on the resistance
range, infact this ought to be the first thing to look at.

Davy

.

Relevant Pages

  • Re: HP LaserJet 8100/8150 Low Voltage Power Repair
    ... SMPS. ... from the switch-mode transformer ought to be contain fuses, ... If other voltages are there then you can be pretty certain that the ... The fuser is a heater is the fuser element intact, ...
    (comp.periphs.printers)
  • Re: Defective Power supply in HP8711a Network Analyser.
    ... Going back to basics it proved that the SMPS of the HP8711a hates it ... out that the -15 Volt GND return hates it to be connected to GND of ... the cabinet (this connection is on the backplane of the 8711) or to ... GNDs of the other voltages. ...
    (sci.electronics.equipment)
  • Re: Defective Power supply in HP8711a Network Analyser.
    ... Going back to basics it proved that the SMPS of the HP8711a hates it ... out that the -15 Volt GND return hates it to be connected to GND of ... the cabinet (this connection is on the backplane of the 8711) or to ... GNDs of the other voltages. ...
    (sci.electronics.equipment)
  • CTX PL9 Blowing HOT
    ... Got a CTX PL9 monitor just quit working. ... LED comes on ok and all voltages are good at SMPS. ... Power supply was not coming up after I shorted it. ...
    (sci.electronics.repair)