HP 9845 C with 280 option startup failure
tequilizer at gmx.net
Sun Oct 23 02:34:46 CDT 2005
I recently acquired a HP 9845C option 280 (was looking for it for a
really long time).
The machine is in an overall good condition, however it hangs during
memory test ("MEMORY TEST IN PROGRESS"), even after cleaning all board
connectors, resocketing all ROMs & repeated control-stop's. Before
entering nirvana the printer outputs a couple of memory addresses.
Although lots of defects may be responsible, I assume there is a
combination of both a bad RAM chip and a ROM failure, since a RAM defect
alone should (?) not crash the system during the test.
The printout looks like this:
000000 100112 052525
000000 110112 052525
000000 120112 052525
000000 130112 052525
I guess the first number is the block ID, the next is the memory address
within the block, and the last number is the test pattern, each in octal
Does anyone have an idea
- how to really interpret the memory test printouts and
- how to check the ROMs for bad data?
Maybe there is anyone out there who did the job to read out the contents
of his 9845 ROMs (they are all in sockets) for a direct comparison.
There is a 98407A memory option installed, and, of course, a bit slice
LPU. So the ROMs work out as:
CE1 LB: 1818-1591B
CE1 UB: 1818-1592B
CE2 LB: 1818-0846D
CE2 UB: 1818-0841D
CE3 LB: 1818-0837D
CE3 UB: 1818-0833D
CE4 LB: 1818-1898A
CE4 UB: 1818-1899A
CE1 LB: 1818-1506A
CE1 UB: 1818-1502A
CE2 LB: 1818-1507A
CE2 UB: 1818-1503A
CE3 LB: 1818-1508A
CE3 UB: 1818-1504D
CE4 LB: 1818-1509A
CE4 UB: 1818-1505A
Most of them schould be the same as in an 9845B model 200 system.
Thanks for your help
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