Checking The A18 Cpu Voltages; Verifying The A18 Cpu Turn-On Sequence - Keysight Technologies E8257D Service Manual

Troubleshooting
A18 CPU Turn–On Test
4. Inspect the pins on the A31 Motherboard connector. If the pins look good
5. If either of the voltages are missing, refer to
6. If DS9 and DS10 are on, proceed to

Checking the A18 CPU Voltages

1. With the external and internal covers removed and the signal generator on
2. If all the power supply LEDs on the motherboard are on, check the A18
Connector
P223–2, 22
P223–3
P223–4
P223–21
P223–23
P223–37
P223–39
P223–40
3. If any main power supply voltage problems are detected, refer to
4. If all power supply voltages are good, replace A18 CPU.
Verifying the A18 CPU Turn–On Sequence
Verify the A18 CPU turn–on sequence by observing DS1 to DS8 sequence
patterns (See the diagram on
match the sequence shown in
sequence, make sure all switches in the upper left–hand corner of the A18 CPU
are in the CLOSED (up) position. If the lights fail to step through the sequence,
replace A18 CPU.
E8257D/67D, E8663D PSG Signal Generators Service Guide
replace the A18 CPU.
Troubleshooting" on page
page 23.
its side, turn power on and check to see if all the power supply LEDs on the
A31 Motherboard are on. If any of the power supply LEDs are not on, refer
to "Power Supply Troubleshooting" on page 37
CPU and A31 Motherboard connector pins for the voltages listed in the
following table.
Supply Troubleshooting" on page
37.
"Checking the A18 CPU Voltages" on
Supply Vol tage
+5 VA
−15 V_In
+32 V_In
+15 V_Standby
+15 V_In
−7 Vdc
+10 Vdc
+8 Vdc
37.
page 76 for LED locations). DS1 to DS8 should
Table 1-3. Before verifying the turn–on
"Power Supply
to troubleshoot.
Acceptable Range
+5.2 ± 0.16 Vdc
−15 ± 0.45 Vdc
+32 ± 0.96 Vdc
+14.85 ± 0.6 Vdc
+15 ± 0.75 Vdc
−7.0 ± 0.14 Vdc
+10.2 ± 0.2 Vdc
+7.95 ± 0.21 Vdc
"Power
23