Service Rom Tests - HP Integral Personal Computer Service Manual

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8.5.3 Service ROM Tests
Now run the service ROM tests as follows:
CAmoN
Before installing or removing the service ROM aaeembly, tum off the computer. Otherwise seri-
ous damage to the unit may occur.
Use care when you install or remove the ROM assembly. Be sure that the assembly is right-side
up (there are two guides on the bottom of the assembly) and that it
is
aligned properly be(ore
you
try to insert it.
The
ROM connecting pins in the ROM receptacle are very easily damaged.
1.
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Turn off the computer and ctisconnect it from the power.
2. Remove the ROM door from the back of the computer, remove the operating system ROM assem-
bly, and install the service ROM assembly.
3.
Remove the customer's interfaces and memory modules, and install a
known-good
RAM module
in
port
A.
4. Reconnect the power to the computer.
S. Insert a
formatted
floppy disc into the disc drive. Do not use a disc that contains useful data. Any
data on the disc will be destroyed during the test.
L _ ........ Teat. Tum on the computer. After power up, the service ROM sequence test runs
automatically. This test checks the following cirQIits:
• Internal RAM.
• MMU (memory management unit).
• Keyboard (short test).
• Display /GPU. (If there is a GPU failure, the speaker will output a
descending
musical scale.)
Watch the series of patterns to check for display problems.
• Floppy disc drive.
• RTe (real-time clock). .
• External RAM. (Since the RAM module is known to be good, this test indicates whether the
port
A I/O bus data and address lines are good.)
• Speaker. An
ascending
musical scale is output to verify speaker operation.
• Internal HP-IB (short test).
• Printer (short test).
Refer to section 8.2.2 for a description of these tests. An appropriate message will be displayed
after each test is passed. If a test is failed, an error message will be displayed. After the internal
RAM, MMU, keyboard, and display/CPU tests are done, you can halt the sequence test by press-
ing any key.