HP HP-97 - Page 114

Component-Level Maintenance HP-97
Table 4-15. Card-Reader PCA Troubleshooting Procedure (Continued)
STEP ACTION
15.
Measure the resistance across
each of the capacitors C1 and C2. If the resistance is > 10 kohms,
go to step 16.
If not, replace the capacitor(s).
Then go to step 16.
16.
Monitor the RA and RB pins of
the CRC while reading side 1 of
data card 2. If RA and RB are rectangular wave-
forms with amplitudes at least
equal to 3.0 Vdc (see figure 4-20)
go to step 17.
If not, replace the sense amp.
and repeat step 16.
If the waveforms are still not
correct, replace the CRC and
repeat step 16.
If the waveforms are still not
correct, check the traces.
Then return to step 14.
17.
Replace the CRC.
18.
Read side 1 of data card 2. If "ERROR" is not displayed, re-
turn to step 2.
If so, replace ROM 6 and read side
1 of data card 2.
If "ERROR" is not displayed,
return to step 2.
If so, check traces and dis-
crete components. Then return
to step 14.
4-46