Laser printer: fish smell, then dead

[JT]

My Lexmark/IBM laser printer exuded a sharp fishy smell for a couple
of weeks. I guessed it was something that had gotten into the paper
path and was more an annoyance than anything more serious, and once
took out the toner card and dusted the thing out and it seemed to
diminish. Then yesterday halfway through making a print it just turned
off and won't come back on.

The PS seems to be working except that there's no voltage on the two
heavy black leads that disappear into the machine itself (as opposed
to the logic board on the side.)

 

[Tom MacIntyre]

My Lexmark/IBM laser printer exuded a sharp fishy smell for a couple
of weeks. I guessed it was something that had gotten into the paper
path and was more an annoyance than anything more serious, and once
took out the toner card and dusted the thing out and it seemed to
diminish. Then yesterday halfway through making a print it just turned
off and won't come back on.

The PS seems to be working except that there's no voltage on the two
heavy black leads that disappear into the machine itself (as opposed
to the logic board on the side.)

Bad electrolytic capacitor.

Tom

 

[David]

Are you sure his cat didn't vomit lunch into the printer?


Otherwise the printer is probably looking at all the electrolytic
capacitors, due to the specific age and bad vintage of caps used.

 

[James Sweet]

My Lexmark/IBM laser printer exuded a sharp fishy smell for a couple
of weeks. I guessed it was something that had gotten into the paper
path and was more an annoyance than anything more serious, and once
took out the toner card and dusted the thing out and it seemed to
diminish. Then yesterday halfway through making a print it just turned
off and won't come back on.

The PS seems to be working except that there's no voltage on the two
heavy black leads that disappear into the machine itself (as opposed
to the logic board on the side.)

Does it have any surface mount electrolytic capacitors in it? If so they're
probably all leaking. When failing, they smell strongly of rotting fish.

 

[JT]

Thanks for the suggestions. Everyone agrees that bad electrolytics =
bad fish, so it must be so, tho I've never noticed any smell from a
bad cap. Maybe in other cases the resistor or other part that caused
the cap to go overpowered the fish.

Since the thing seems dead I expected the PS to have blown but as I
said it's putting out at least a couple of voltages - all but whatever
belongs on those two big black leads.

And everything on both sides of the PS pcb looks good as new. The data
processing pcb is on the right and readily accessible and at least the
top side looks great. Nothing oozing, nothing discolored, nothing
bulging. Nothing smelling like feesh. There's a small pcb under the
mechanism that I haven't figured out how to access. Jack hammer?
What's likely supposed to be on the two heavy black leads (heavy being
maybe 16 ga) that go into the area of the mechanism? Presumably laser
and heater power.

John

 

[Jerry G.]

This type of fish smell is from bad electrolytic capacitors. When this smell
is present, the defective cap is very bad.

--

Jerry G.
=====


My Lexmark/IBM laser printer exuded a sharp fishy smell for a couple
of weeks. I guessed it was something that had gotten into the paper
path and was more an annoyance than anything more serious, and once
took out the toner card and dusted the thing out and it seemed to
diminish. Then yesterday halfway through making a print it just turned
off and won't come back on.

The PS seems to be working except that there's no voltage on the two
heavy black leads that disappear into the machine itself (as opposed
to the logic board on the side.)

 

[LASERandDVDfan]

Thanks for the suggestions. Everyone agrees that bad electrolytics =

bad fish, so it must be so, tho I've never noticed any smell from a
bad cap. Maybe in other cases the resistor or other part that caused
the cap to go overpowered the fish.

Electrolytics are a kind of cap. They are known as electrolytic capacitors,
meaning that they have a liquid electrolyte solution suspended within a
retention medium inside the can which works as the condensing medium to store
an electrical charge at or close to the indicated capacity typically indicated
in microfarads, with a magin of error of + or - 5%-20% of the indicated value
for condenser-type caps.

A leaky electrolytic cap loses its capacitive value and can also gain high ESR,
can short out, or can go "open circuit" so it stops working as a coupler or a
condenser, depending on what the cap is being used for in the affected circuit.

With caps, all it takes to stop something from working is for a cap to drift
far out of value and/or literally become an electrical resistor (with
resistance indicated as ESR) in a circuit.

As for the reason why the caps failed, they can fail when they are overheated,
if they were fed power beyond their tolerance ratings, or they just simply fail
for no reason other than the cap may have been internally defective or just
old.

In your case, the caps in your printer probably just failed with nothing in the
printer itself to cause the failure. If the problem was a bad resistor, as
you've suggested, the printer would have likely stopped working almost
immediately long ago. - Reinhart