Bosch HBL 73 Service Manual page 34

ELETTRODOMESTICI
VIA CHECCHI 98
I 21013 GALLARATE
ITALY
USEFUL INFORMATION ABOUT THE ELECTRONIC CONTROL:
1. SHORT POWER OFF. In case of power loss for a short time, the control saves the currently active settings in its memory. It
fetches all these values as soon as power recovers. The oven comes back to the same working condition it was before the
power drop. Such a time is variable, more or less a few dozens of seconds, depending on the tolerances of some components
on the electronic boards.
2. LONG POWER OFF. When the time expires, the control forgets the former working condition and, as soon as power recovers,
it performs a complete reset. It shows the SW code numbers and the writing "UNLOCKING DOOR", while the power-up latch
auto-test is running. The control is now in a stand-by state; the clock is blinking, waiting for a new user operation. This means
that, in case of problems with the latch positioning, the best thing to do is turn off the oven, wait at least for one minute before
re-powering the unit, to cause a system reset and run a complete latch lock/unlock cycle.
3. AVOIDING LATCH AUTO-TEST AT POWER-UP. For whatever reason, if the technician prefers to skip the latch auto-test at
power-up, he just needs to
again.
4. PERSISTING FAULTS OR INHIBITED FUNCTIONS. When the control detects a fault, fist the cause needs to be removed.
Sometimes, for safety reason after a fault, self-clean or even all cooking modes are disabled. Once the fault cause has been
removed, if the disabling condition persists,
press [CANCEL].
5. WARNING: At every power-down, the control saves the time in its memory but sometimes it doesn't succeed in writing the right
checksum value. At the next power-up, the F155 fault code is displayed. Press [Cancel] key to reset the fault, the oven will work
correctly. If F155 is displayed when starting a cooking mode, it means that the Display Board must be replaced, having
corrupted parameters in memory.
Tuesday, June 18, 2002
BOSCH 700 SERIES:
SERVICE INSTRUCTIONS FOR OVEN TESTING AND BASIC TROUBLESHOOTING
keep the [START] key pressed while supplying the oven with power,
keep the [START] key pressed for one minute, until the F121 fault occurs then
Page 3 of 28
until the clock is displayed