MP6500/192 Degree Thermostat Fails/SC555

[Caveman]

MP6500 - 2 million copies - all thermistors, thermostats and holding brackets updated - all SP warm up values changed per Ricoh.

End thermostat - 192 Degree - fails often.

Witnessed generation of the SC555 - upon completion of servicing unit for a feed problem - copier was tested extensively (several hundred copies) - while completing paper work as unit remained in idle 'Ready' condition - the SC555 was generated - upon inspection the 192 degree thermostat was tripped.

All suggestions welcomed.

Thank you.

[mabawser]

make sure all filters are cleaned out and there is space for the machine to circulate the air. had this problem and it took a couple of thermostats before I thought it could be over heating. its a possibility?!?!

[Caveman]

make sure all filters are cleaned out and there is space for the machine to circulate the air. had this problem and it took a couple of thermostats before I thought it could be over heating. its a possibility?!?!

At each service call the filters are inspected and cleaned if necessary. There is adequate space around the unit for proper ventilation. It seems as if the lamps are not cycling properly - remaining on for too long a period causing the thermostat to fail. In the past month I've probably replaced 3 thermostats (AW11-0064 - 192 Degree).

[NeoMatrix]

At each service call the filters are inspected and cleaned if necessary. There is adequate space around the unit for proper ventilation. It seems as if the lamps are not cycling properly - remaining on for too long a period causing the thermostat to fail. In the past month I've probably replaced 3 thermostats (AW11-0064 - 192 Degree).

There is a mod bulletin out for MP 6000/7000. The metal mounting brackets for the thermistor's were changed. The thermistors themselves where made thinner on the H/R contact area....
I assume you have updated to the modifed thinner thermistors etc ?

Drop all the H/R lamp temps 10 degs. Give the thermostats a bit of extra time to over come any thermal shock on warm up.
You could try updating the thermostats to the MPC 3260c thermostats , they operate at 194deg celc.

Have you tried changing the H/R lamps ? You may be getting thermal hot spots; means the lamps may go soon.
Eg. An incandescence light bulb burns the hottest and brightest just before it blows.

HTH
GDM