Intermec EasyCoder 501 - CPU Board Failure

Intermec EasyCoder 501 – Service Manual Ed. 7
200
Chapter 26 Troubleshooting
26.1 Printer “Dead”,
cont.
CPU Board failure
• Ascertain if the trouble is actually due to a hardware defi ciency
and not to the user program having got stuck in some way. This
is easily done by running the print test program, see Chapter
25.
• The various parts of the memory could be checked using the
Fingerprint instruction FUNCTEST$, see Intermec Fingerprint
v6.14, Reference Manual.
• Check that no EPROM or SRAM packages are missing or
incorrectly mounted.
• In case of EPROMs or FLASH memory packages fi tted on
IC-104 and IC-105, check that straps are fi tted correctly on
P-100, P-101, and P-102, see Chapter 17.3.
• Check that Intermec Fingerprint EPROMs IC-100 and IC-101
are marked with IC-1 and IC-2 respectively and that both have
the same part number, see Chapter 17.3.
• Remove EPROMs IC-100 and IC-101 from their sockets and
put them back again (no pins outside the socket holes!).
• Perform a checksum calculation by means of an EPROM pro-
grammer and compare the result with the same EPROMs from
another printer.
• Check that the GAL circuit on IC-04 is fi tted correctly and is of
the correct type (P/N 1-971805-xx).
• Check that the GAL circuit on IC-700 is fi tted correctly and is
of the correct type:
EasyCoder 501 S: P/N 1-971803-xx
EasyCoder 501 E/SA: P/N 1-971804-xx
EasyCoder 501 LL P/N 1-971810-xx
• Check that the ADS signal oscillator is running using ADS test
point, see Chapter 17.7.
• Components mounted on sockets correctly orientated? Pins out
of socket or obviously defective components?
Examine both the soldering and component side of the CPU
Board for possible short-circuits or faulty soldering. Grayish or
blackened lacquer is a symptom of overheating due to excessive
current.
Packages that are smaller than their sock-
ets should always be fi tted as illustrated.
Check that the “Front” mark is pointing
in the direction indicated by the white
markings on the board.
“Front” Mark
CAUTION!
If a RAM package is fi tted upside
down, the diode controlling the battery
recharge could be damaged and
require replacement.