Read Sharp UP-X500 (serv.man18) Technical Bulletin online
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TECHNICAL UPDATE
Countermeasures for Windows reboot problem
Model Name: UP-X500
General:
Windows rebooting itself during operation.
As a countermeasure against this problem a circuit will be changed.
Cause:
When the load to the CPU Core voltage changes from light load to
very heavy load, the voltage may become unstable due to an
very heavy load, the voltage may become unstable due to an
insufficient transient response of the voltage.
In the above case when the voltage exceeds the range of the
stipulated voltage for generation, the power-generating IC outputs
stipulated voltage for generation, the power-generating IC outputs
a Power Good signal to “disable”. As a result, a reset action is
executed for the entire circuit, resulting in the malfunction.
executed for the entire circuit, resulting in the malfunction.
Action:
A condenser 470PF of the C250 is changed to condenser 100PF.
The above measure should be taken individually when the problem
arises.
arises.
The above problem has been resolved at production from April
2004
2004
Model
Name
Current
Part Number
New
Part Number
Price
Rank
Effective
Time
UP-X500
VCKTC1HB471K
VCCCCY1HH101J
AA
2004/04
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