IBM 5280 Manual page 34

B
1
BASE MAP
POWER ON RESET
PAGE
2 OF
5
002
- Leave the probe connected.
Up light: Off
Down light: On
Are the lights correct?
Y N
003
- Check for +5 Vdc from A-C1D03
and A-C3D03 to ground (MIM
501).
Is +4.5 to +5.5 Vdc present at
both pins?
Y N
004
GO TO MAP 8000,
ENTRY POINT A.
005
(ENTRY POINT C>
- Install a jumper at A-A4B04 '-
PO
R
Cl'lN
D' (M I M
501).
- Probe A-C4B04 POR CMND'
(MIM
501).
- Observe the lights as you
mornenturi1y ground the jumper
to -frame ground.
Up light: Ignore
Down light: Pulse
Are the lights correct?
Y N
C D
006
- Defective Keyboard/Display
MPU card (A-A1) (MIM 200).
- If a 'Ros Patch' cable is
connected to the card,
GO TO MAP 0600,
ENTRY POINT A.
C D
f'1AP 0210-2
007
Defective Diskette/Main MPU
car d (A- C 1) ( M 1M3 03) .
- If a 'Ros Patch' cable is
connected to the card,
GO TO MAP 0600, ENTRY POINT A.
008
Power Off.
- Use the C.E. voltmeter set to
the RXI scale.
- Check for a ground at A-C2B04 '-
POR' (MIM 501).
Does the meter have a 5 ohm or
less reading?
Y N
009
- Power On.
- Probe A-C4B04 '- paR CMND'
(MIM 501).
Up light: Off
Down light: On
Are the lights correct?
Y N
3 3
E F
010
Defective Diskette/Main MPU
card (A-Cl) (MIl'1303).
If a 'Ros Patch' cable ;s
connected to the card,
GO TO MAP 0600,
ENTRY POINT A.
EC840874
PEC839787
MAP 0210-2