HP 4262A - Page 257

Set switch A2381
to BCD position,
START / A23PAY
STOP ™\ A23PAY
CLOCK _/~ A22TP2
Window Test
+5V A5097
Go to Figure 8-19,
Flow Diagram B.
Is Signature Set 73 \YES
Stuck Node ?
NO
Check A35U3.
Is Signature Set 74 \NO
START _/~ A23PA9
STOP ™\_ A23PAS
CLOCK "\ A22TP2
OK?
Nanoprocessor
Data Bus Stuck?
YES
Troubleshoot
Stuck Bus.
Troubleshoot
Stuck Node.
Identify incorrect
signature.
Replace defective
component(s),
Check A35U10,
Troubleshoot
Stuck Ius,
Check A35U10.
Figure 8-58. A35 BCD Output Control Board Diagnostic Flow Diagram.
OK?
NO
Shift Resister
Output Bus Stuck ?
NO
Drv ‘Rec Output
Bus Stuck ?
NO
Is Signature at A35
U8 pin 10 (or pin 12)
OK?
NO
Stuck Node?
Is Signature Set 75 YES
Troubleshoot
Stuck Bus,
Is Signaturce at A35
Tp! 11HT?
Output Bus Stuck ?
NO
Check A35U4,
U5, U6 and U7,
Troubleshoot
Stuck Bus.
Check A30UL,
C2 and RS,
Troubleshoot
Stuck Bus.
Check A35U8.
OK?
NO
Shift RU®YES
YES
Is Signature at A35\NO
TDP2 FP44?
Is Stgnature Set 76\ YES
START _/~ A23PA9
STOP \ A23PA9
CLOCK ./~ A22TP2
Troubleshoot
Stuck Bus.
Output
llujw
Is Signature Set 77 \NO
Output Bus Stuck?
Is Signature Set 78 YFS
OK?
NO
Is Sinature Set 77 \NO
OK?
Check A35U2,
Check A3SUL,
C2 and R5.
YES YES
Check A35U9, ULl, Troubleshoot
U12 and U13. Stuck Bus,
Go to Figure 8-1¢
Flow Diagram B.