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Time to fork hpsetdisp.pl for some real fun. Besides, I have a printer at work that needs replacing. http://kovaya.com/perl/show.cgi?program=hpsetdisp.pl http:

Time to fork hpsetdisp.pl for some real fun. Besides, I have a printer at work that needs replacing. http://kovaya.com/perl/show.cgi?program=hpsetdisp.pl http://kovaya.com/perl/show.cgi?program=hpsetdisp.pl From the article: >>"HP LaserJet printers have a hardware element called a 'thermal breaker' that is designed to prevent the fuser from overheating or causing a fire. It cannot be overcome by a firmware change or this proposed vulnerability." I wouldn't be so sure about that last part, but I do doubt that the things can be made to cause adjacent objects to catch fire (unless maybe someone stores their gasoline in open containers near the printer).

ams6110 14y ago
A thermal breaker is a purely mechanical device, it opens the electrical circuit if temperature rises beyond its designed limit. It is not controlled by software. It is designed to be a failsafe against another hardware or software problem which is causing an overheating condition. I think HPs claim on at least that issue is credible.
- fnordfnordfnord 14y ago
  Yes, I know what a thermal breaker is, and that the switch itself cannot be affected by firmware, so he is correct in that statement, but that is so obvious that doesn't really need mentioning. What I mean is that the protection that is intended by the thermal switch might be cleverly defeated. The thermal switch is usually mounted on the (metal frame) chassis, not always close to the parts that would catch fire. What I am suggesting is that one might find a way to cause a paper jam, and then get the paper to ignite before the chassis were heated enough to cause the thermal switch to open. It might even be dependent upon a specific model(s). I doubt it is possible to prevent without very careful placement of thermal switch(es). The kind of placement that would defy efficient manufacturing ideals, and possibly even user-safety-inspired design practices. TBH, I don't think it is likely to be a reliable ignition method. Besides, Randall Hyde has shown us the most satisfying way to get rid of printers (buckshot).
  - monochromatic 14y ago
    If I were HP, I think I'd put it right by the fuser. (Although I would also do a lot of other things differently, so that may not be a strong point.)

ams6110 14y ago

A thermal breaker is a purely mechanical device, it opens the electrical circuit if temperature rises beyond its designed limit. It is not controlled by software. It is designed to be a failsafe against another hardware or software problem which is causing an overheating condition. I think HPs claim on at least that issue is credible.

fnordfnordfnord 14y ago
Yes, I know what a thermal breaker is, and that the switch itself cannot be affected by firmware, so he is correct in that statement, but that is so obvious that doesn't really need mentioning. What I mean is that the protection that is intended by the thermal switch might be cleverly defeated. The thermal switch is usually mounted on the (metal frame) chassis, not always close to the parts that would catch fire. What I am suggesting is that one might find a way to cause a paper jam, and then get the paper to ignite before the chassis were heated enough to cause the thermal switch to open. It might even be dependent upon a specific model(s). I doubt it is possible to prevent without very careful placement of thermal switch(es). The kind of placement that would defy efficient manufacturing ideals, and possibly even user-safety-inspired design practices. TBH, I don't think it is likely to be a reliable ignition method. Besides, Randall Hyde has shown us the most satisfying way to get rid of printers (buckshot).
- monochromatic 14y ago
  If I were HP, I think I'd put it right by the fuser. (Although I would also do a lot of other things differently, so that may not be a strong point.)