Data General NOVA 4/S Manual page 44

. Turn the power on.
. Turn the power on.
). Check the over-current light.
sure to insert the correct jumpers (see 'Memory
Board Replacement," Chapter 14, or the
circuit board you have not already tried removing.
installation data sheets, DGC No. 010-000213, for
Over-Voltage Light
. Turn the power off.
2. Replace the power supply board.
. Turn the power on.
. If the light is still on, replace the CPU board.
f o o
# Be
138-21
Voltage Checkout
1.
2.
LZ
Turn the power on.
Check the +5V voltage at test plug J1-15 (see
Figure 6.8). If +5V is between 5.10V and 5.20V, go
to "Final Checkout"; otherwise, continue' the
. Turn the power off.
. Short MEMD at J35-21 to GND at J35-1 (see Figure 6.7).
. Turn the power on and check the memory disaster
a. If the light is NOT on, turn the power off, remove
the short, and replace the VNR unit.
b. If the light is on, turn the power off, remove the
short, and then turn the power on.
e Check the -11V voltage at J35-25 (see Figure
e If -11V is NOT between -11.0V and -12.5V
(-30VNR not ok), check the VREF at test plug
J1-14 (see Figure 6.8). If VREF is 5.8V, replace
the VNR unit; otherwise, replace the power
supply board.
e If -11V is between -11.0V and -12.5V (-30VNR
ok), check the HVS voltage at test plug J1-4
(see Figure 6.8). If HVS is greater then 2.9V,
replace the power supply board; otherwise,
replace the VNR unit.
. Recheck the +5V voltage at test plug J1-15 (see
Figure 6.8). If it is between 5.10V and 5.20V, go to
"Final Checkout"; otherwise, try replacing the
internal cable (wiring harness). If this does not work,
get help from DGC Field Service.
J35-2;0 DODOOO OOOO OoDODOoOoOoOoODDoOooODy35-50
J35
Figure6.7 JACK J35