EIP 545A - Page 57

START
s.
PROGRAM IS NOT
RUNNING PROPERLY.
POWER SUPPLY OR
CHECK POWER SUPPLIES.
POWER
LINE INPUT BAD.
I
1
I I
4 GOOD
I CONNECT SCOPE TO I
A105U1 PIN 40
TURNCOUNTEROFF,THEN
POWER ON
BACK ON. AT TURN ON DOES PIN
RESET CIRCUITRY
-a- I
40 GO-LOW FOR APPROX: 50 ms,
I
BHU I
THEN GO HIGH?
YES
CONNECT SIGNATURE
ANALYZER AS INDICATED IN ONE OF THE PROM OR RAM
Figure 6-2 (Basic PROM Set)
CHIPS IS BAD.
PROBE ALL POINTS INDICATED.
ARE ALL SIGNATURES GOOD?
REMOVE A105 JMPl
GROUND A105 TP5.
CONNECT SIGNATURE
ANALYZER AS INDICATED IN
'FIGURE 6-1.
PROBE ALL POINTS INDICATED.
ARE ALL SIGNATURES GOOD?
YES
TURN COUNTER OFF
REMOVE GROUND
FROM A105 TP5
REPLACE A105 JMPl
REMOVE ALL PCB's EX-
CEPT MICROPROCESSOR
(A1051
AND DISPLAY (A1 10).
TURN UNIT ON. DOES UNIT
DISPLAY DASHES FOR APPROX.
1 SEC. THEN DISPLAY ZEROS?
YES
1 1
N 0
A105 U10 BAD, OR DATA BUS ON
MOTHER BOARD
(A100) OR DIS-
PLAY LOGIC BOARD (A1 10) BAD.
PROBE TO POINT WHERE BAD
SIGNATURE STARTS. REPLACE
BAD COMPONENT.
1 YES
ONE AT A TIME REPLACE PC
BOARDS AND REPEAT PREVIOUS
STEP UNTIL BAD BOARD IS
FOUND. DATA BUS OR PIA ON
THAT BOARD IS BAD.
Figure 612. Program Inoperative
Scans by ArtekMedia © 2007