IBM 5280 Manual page 36

H J
3 3
BASE t'1AP
POWER ON RESET
PAGE
4 OF
5
020
Power O-ff.
- Use the C.E. voltmeter set to
the RXI scale.
Check for a ground at A-A8B04
'+
POR' (MIM 501).
Does the meter have a 5 ohm or
less reading?
Y N
021
- Defective
Diskette/Mai~
MPU
card (A-Cl) (MIN 303).
If a 'Ros Patch' cable
connected to the card,
GO TO MAP 0600,
ENTRY POINT A.
022
- Use MIM 531 for
'+
POR'.
is
- Remove the cards in the net,
one at a time, until the meter
reading is 100 ohms or more.
- If all cards have been
removed, and the meter reading
is still zero ohms, check the
logic. board for a ground.
023
- Probe A-A4B02 '100 Hz'
501 ) .
Up light: On
Down light: On
Are
th~
lights correct?
Y N
5
K L
(t'1I t' 1
L
t'1AP 0210-4
024
- Leave the probe connected.
Up light: Off
Down light: On
Are the lights correct?
Y N
025
The logic board is open '100
Hz' <t'lIM
531).
- - OR
- Defective Diskette/Main MPU
card (A-Cl) (MU1 303).
If
a
'Ros Patch' cable is
connected to the card,
GO TO MAP 0600, ENTRY POINT
A.
026
Power off.
Use the C.E. voltmeter set to
the RXl scale.
- Check for a ground at A-A4B02
'100 Hz' (MIM 501).
Does the meter have a 5 ohm or
less reading?
Y N
5
M
027
Defective Diskette/Main MPU
car d (A- C 1) ( M I t' 1 303).
- If a 'Ros Patch' cable is
connected to the card,
GO TO MAP 0600, ENTRY POINT A.
EC840874 PEC839787
MAP 0210-4