On Wed, 15 Jan 2014 01:41:27 +0000, T i m wrote:
My wild guess(tm) is that the 170C was too low in temperature to stay
closed while the printer was being used as a printing press. The
manufacturer usually recommends a duty cycle, such as 20 mins print,
10 minutes rest, etc which of course, nobody follows.
Hehe.
Before electronic filing, my tax preparer customers would run their
laser printers almost full time during late tax season. Five inch
thick returns were common. A floor fan blowing on the printer was
also common. All of them went through the same exercise. They would
buy a cheap laser printer, run it like a printing press, destroy it,
and then buy something more suitable.
HP is unique in that it has a built in safety feature to prevent
overheating and over use. It's the sticky solenoid and foam rubber
pad I mentioned in a previous rant. When the machine is cold, the
solenoids work normally. However, as the solenoid becomes hot from
use, the glue and foam rubber pad melts, causing the solenoid armature
to stick to the frame. The timing error usually produces a paper jam
which offers the user a chance to slow down while practicing
profanity.
There has been some suggestion the sticky foam safety feature is not
intentional, but I suspect otherwise. HP has used exactly the same
design for their sticky solenoid safety feature since the HP LJII
which suggests that it's a successful method of controlling the
printing duty cycle.
Well, I've set it to 'sleep' after 5 mins and after 30 mins you can
still feel warmth coming out of the paper exit port (I assume that to
also be a thermal vent for the fuser).
I use a Kill-a-watt AC power meter to measure power consumption in
various states. Occasionally, my measurements agree with the data
sheet. You might want to measure the standby and power save power
consumption, which offer clues as to the fuser power consumption.
I like the HP 2300DTN printer.
Googles It looks fairly 'chunky'?
It's bigger than your P2025 but not as big as a production printer
such as a 4150, 4250, or 4300. Certainly smaller than an 8000 series
printer. Two of mine show about 80,000 pages. The other is at about
10,000 because I replaced the formatter board. I replace most of the
rubber parts when I rebuild a printer. I get about 5000 pages per
toner cart. If you want better, you'll have to live with bigger.
I think I can find a replacement single thermostat in the US for much
less. Later tonite...
Oh, cool, thanks (but aren't we still unsure what role both devices
covered? Stat+backup stat. Stat+Overtemp Stat? Stat+Thermal fuse?
Yep. If my guess is correct about thermostat cycling due to excessive
use, putting in the wrong thermostat will make it worse if set to a
lower temperature, or melt the fuser if set to a higher temperature.
At this point, I would so some measuring with an IR thermometer or
thermocouple. My guess(tm) is that the operating temperature is too
close to the thermostat temperature.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558