Nortel Meridian 1 Succession 1000 Description page 255

Table 40
M1250 failure codes (Part 2 of 2)
Failure code Reason
90H The RS-232 port has failed
the loopback test.
88H The EPROM, U18, does not
contain the correct ID, or is
faulty.
M2250 failure codes
M1250 and M2250 Attendant Consoles
The failure codes produced by the firmware are bit-significant, as follows:
B7 B6
0 USART
1 SRC
* Refers to key's column number.
In most instances, the failure code accurately identifies the faulty hardware
component. However, if the microprocessor is faulty, the readings may be
unreliable or misleading.
Failure code 90H is always shown if the loopback test has not been
performed. Refer to "Testing the data port" on
A failure code appears on the display in response to the detection of a
hardware fault.
What to do
Check to see if the loopback connector is
inserted. If not, insert it and perform the
loopback test again. If the failure code still
appears, turn the console off and on while the
connector is inserted. Redo the loopback test.
If the failure code still appears, the console is
faulty and should be returned.
Same as for 20H.
B5 B4
RTC RAM
BLF RS232
Telephones and Consoles
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B3 B2
KEYS c2
EPROM 0
page 250.
B1 B0
c1 c0*
0 0
Description