HP Integral Personal Computer Service Manual page 102

TN_ ... hootIng .............. 11_ 8-18
TIIIIIe "3. """"Iupplf VertftCldlon (Continued)
1 L Remove the plug-in ROM assembly, turn on
the power, and measure the voltages on the
test tool as in step 7.
13. Reconnect the power-cable harness to the
disc drive, then turn on the power. Check
the voltages at the power supply test tool as
in step 7 above.
14. Remove the power supply test tool, recon-
nect the power-cable harness to the logic B
PCA.
I
The display will show only a blank raster pat-
tern without the ROM, but
you
can
check the
pO'Wer supply voltages. If the voltages are still
not within specification or if the fuse blows,
troubleshoot or replace the logic A peA.
If the voltages are now within specification, the
problem is in the plug-in ROM assembly:
• For a System III ROM assembly, replace the
whole assembly.
• For a System V ROM assembly that contains
no option ROM peA, replace the operating
system ROM peA.
• For a System V ROM assembly that contains
an option ROM peA, remove the option
ROM peA and turn on the computer with
just the operating system ROM peA in-
stalled. If the voltages now check good,
replace the option ROM PCA. If the voltages
are still bad or if the fuse blows, replace the
operating system ROM peA.
[f
the voltages are all within specification, go to
step 14.
If any of the voltages are out of range, or if the
fuse blows, replace the disc drive.