- Joined
- Mar 8, 2002
- Posts
- 3,686
I've recently won a 4-slot on ebay that was stuck into hardware test (aka crosshatch screen). While searching for threads on this topic in the tech forum archives I've noticed that the problem seems to affect 4-slots more than other motherboards and in particular the older version of the 4-slot, the one with four 64-pin connectors holding the bottom and top PCBs together (the newer version only has three of these connectors). This recent thread and my own experience led me to the conclusion that one of the causes (perhaps the most typical one?) is trace corrosion due to battery leakage. As you can see in this picture, the backup battery (here removed) is located too close to the traces that go to CN10 (one of the four PCB interconnections). You can even see that the green coating on some traces is partly off. In my case the trace going from pin B7 of CN10 to pin 16 of a nearby IC was totally eaten up by corrosion. After soldering a wire between the two points I had a fully working 4-slot:
http://img473.imageshack.us/img473/161/cn10fixed2pp.jpg
In the other thread linked above the problem was another of the traces more exposed to a possible battery leakage. So in case you have an older 4-slot with a crosshatch screen problem that is not fixed by simply reseating the top PCB, cleaning the connectors or setting DIP switch 1 off, the next thing you may want to do is check the connections of CN10. To make things easier for you I've written down where all the traces go from the 4 PCB interconnections (not only CN10 but also CN8, CN9 and CN11) to the various components on the bottom board. The components are assigned number and letter coordinates found on the actual PCB. For instance:
CN10
A5 B7 (2)
is meant to be read as pin A5 of CN10 is connected to pin 2 of the component (a 74AS245) located at B7.
CN10
A1 +5V
A2 +5V
A3 +5V
A4 +5V
A5 B7 (2)
A6 B7 (3)
A7 B7 (4)
A8 B7 (5)
A9 B7 (6)
A10 B7 (7)
A11 B7 (8)
A12 B7 (9)
A13 B8 (2)
A14 B8 (3)
A15 B8 (4)
A16 B8 (5)
A17 B8 (6)
A18 B8 (7)
A19 B8 (8)
A20 B8 (9)
A21 B8 (1), C11 (3)
A22 C11 (5)
A23 C11 (7)
A24 C11 (9)
A25 C11 (12)
A26 C11 (14)
A27 C11 (16)
A28 C11 (18)
A29 GND
A30 GND
A31 GND
A32 GND
B1 +5V
B2 +5V
B3 +5V
B4 +5V
B5 B9 (18)
B6 B9 (3)
B7 B9 (16)
B8 B9 (5)
B9 B9 (14)
B10 B9 (7)
B11 B9 (12)
B12 B9 (9)
B13 B10 (18)
B14 B10 (3)
B15 B10 (16)
B16 B10 (5)
B17 B10 (14)
B18 B10 (7)
B19 B10 (12)
B20 B10 (9)
B21 B11 (18)
B22 B11 (3)
B23 B11 (16)
B24 B11 (5)
B25 PRO-C0 (72)
B26 PRO-C0 (74)
B27 PRO-C0 (75)
B28 PRO-C0 (73)
B29 GND
B30 GND
B31 GND
B32 GND
The ICs:
B7 = 74AS245
B8 = 74AS245
B9 = 74HC244
B10 = 74HC244
B11 = 74AS244
C11 = 74AS244
------------------------------
CN8
A1 +5V
A2 +5V
A3 +5V
A4 SC2 (15), PRO-CT0 (15)
A5 SC2 (13), PRO-CT0 (16)
A6 SC2 (10), PRO-CT0 (21)
A7 SC2 (8), PRO-CT0 (22)
A8 SC2 (6), PRO-CT0 (23)
A9 SC2 (4), PRO-CT0 (24)
A10 NOT CONNECTED
A11 R2 (1), R3 (3)
A12 NOT CONNECTED
A13 NOT CONNECTED
A14 P1 (9)
A15 P1 (12)
A16 P1 (7)
A17 P1 (14)
A18 P1 (5)
A19 P1 (16)
A20 P1 (3)
A21 P1 (18)
A22 R1 (9)
A23 R1 (12)
A24 R1 (7)
A25 R1 (14)
A26 R1 (5)
A27 R1 (16)
A28 R1 (3)
A29 R1 (18)
A30 GND
A31 GND
A32 GND
B1 +5V
B2 +5V
B3 +5V
B4 SC2 (14), PRO-CT0 (19)
B5 SC2 (12), PRO-CT0 (20)
B6 SC2 (9), PRO-CT0 (25)
B7 SC2 (7), PRO-CT0 (26)
B8 SC2 (5), PRO-CT0 (27)
B9 SC2 (3), PRO-CT0 (28)
B10 SFIX (13)
B11 SFIX (14)
B12 SFIX (15)
B13 SFIX (17)
B14 SFIX (18)
B15 SFIX (19)
B16 SFIX (20)
B17 SFIX (21)
B18 R3 (12)
B19 R3 (14)
B20 R3 (16)
B21 R3 (18)
B22 R2 (11)
B23 R2 (12)
B24 R2 (13)
B25 R2 (14)
B26 R2 (15)
B27 R2 (16)
B28 R2 (17)
B29 R2 (18)
B30 GND
B31 GND
B32 GND
The ICs:
P1 = 74AS244
R1 = 74AS244
R2 = 74AS245
R3 = 74AS244
------------------------------
CN9
A1 +5V
A2 +5V
A3 +5V
A4 R11 (9)
A5 R11 (12)
A6 R11 (7)
A7 R11 (14)
A8 R11 (5)
A9 R11 (16)
A10 R11 (3)
A11 R11 (18)
A12 R10 (9)
A13 R10 (12)
A14 R10 (7)
A15 R10 (14)
A16 R10 (5)
A17 R10 (16)
A18 R10 (3)
A19 R10 (18)
A20 SC1 (19), PRO-CT0 (59)
A21 SC1 (17), PRO-CT0 (60)
A22 SC1 (15), PRO-CT0 (61)
A23 SC1 (13), PRO-CT0 (62)
A24 SC1 (10), PRO-CT0 (5)
A25 SC1 (8), PRO-CT0 (6)
A26 SC1 (6), PRO-CT0 (7)
A27 SC1 (4), PRO-CT0 (8)
A28 SC2 (19), PRO-CT0 (13)
A29 SC2 (17), PRO-CT0 (14)
A30 GND
A31 GND
A32 GND
B1 +5V
B2 +5V
B3 +5V
B4 P11 (9)
B5 P11 (12)
B6 P11 (7)
B7 P11 (14)
B8 P11 (5)
B9 P11 (16)
B10 P11 (3)
B11 P11 (18)
B12 P10 (9)
B13 P10 (12)
B14 P10 (7)
B15 P10 (14)
B16 P10 (5)
B17 P10 (16)
B18 P10 (3)
B19 P10 (18)
B20 SC1 (18), PRO-CT0 (1)
B21 SC1 (16), PRO-CT0 (2)
B22 SC1 (14), PRO-CT0 (3)
B23 SC1 (12), PRO-CT0 (4)
B24 SC1 (9), PRO-CT0 (9)
B25 SC1 (7), PRO-CT0 (10)
B26 SC1 (5), PRO-CT0 (11)
B27 SC1 (3), PRO-CT0 (12)
B28 SC2 (18), PRO-CT0 (17)
B29 SC2 (16), PRO-CT0 (18)
B30 GND
B31 GND
B32 GND
The ICs:
R10 = 74LS244
R11 = 74LS244
P10 = 74LS244
P11 = 74LS244
------------------------------
CN11
A1 +5V
A2 +5V
A3 +5V
A4 +5V
A5 F2 (14)
A6 F2 (12)
A7 F2 (9)
A8 F2 (7)
A9 F2 (3)
A10 F2 (5)
A11 G2 (5)
A12 G2 (16)
A13 G2 (9)
A14 G2 (12)
A15 G2 (7)
A16 G2 (14)
A17 G2 (18)
A18 G2 (3)
A19 F2 (16)
A20 NOT CONNECTED
A21 B11 (14)
A22 G10 (13)
A23 NOT CONNECTED
A24 NOT CONNECTED
A25 NOT CONNECTED
A26 NOT CONNECTED
A27 NOT CONNECTED
A28 NOT CONNECTED
A29 GND
A30 GND
A31 GND
A32 GND
B1 +5V
B2 +5V
B3 +5V
B4 +5V
B5 F1 (9)
B6 F1 (8)
B7 F1 (7)
B8 F1 (6)
B9 F1 (5)
B10 F1 (4)
B11 F1 (3)
B12 F1 (2)
B13 G1 (9)
B14 G1 (8)
B15 G1 (7)
B16 G1 (6)
B17 G1 (5)
B18 G1 (4)
B19 G1 (3)
B20 G1 (2)
B21 B11 (7)
B22 B11 (12)
B23 B11 (9)
B24 NOT CONNECTED
B25 NOT CONNECTED
B26 NOT CONNECTED
B27 NOT CONNECTED
B28 NOT CONNECTED
B29 GND
B30 GND
B31 GND
B32 GND
The ICs:
B11 = 74AS244
F1 = 74LS245
F2 = 74LS244
G1 = 74LS245
G2 = 74LS244
G10 = LS138
------------------------------
http://img473.imageshack.us/img473/161/cn10fixed2pp.jpg
In the other thread linked above the problem was another of the traces more exposed to a possible battery leakage. So in case you have an older 4-slot with a crosshatch screen problem that is not fixed by simply reseating the top PCB, cleaning the connectors or setting DIP switch 1 off, the next thing you may want to do is check the connections of CN10. To make things easier for you I've written down where all the traces go from the 4 PCB interconnections (not only CN10 but also CN8, CN9 and CN11) to the various components on the bottom board. The components are assigned number and letter coordinates found on the actual PCB. For instance:
CN10
A5 B7 (2)
is meant to be read as pin A5 of CN10 is connected to pin 2 of the component (a 74AS245) located at B7.
CN10
A1 +5V
A2 +5V
A3 +5V
A4 +5V
A5 B7 (2)
A6 B7 (3)
A7 B7 (4)
A8 B7 (5)
A9 B7 (6)
A10 B7 (7)
A11 B7 (8)
A12 B7 (9)
A13 B8 (2)
A14 B8 (3)
A15 B8 (4)
A16 B8 (5)
A17 B8 (6)
A18 B8 (7)
A19 B8 (8)
A20 B8 (9)
A21 B8 (1), C11 (3)
A22 C11 (5)
A23 C11 (7)
A24 C11 (9)
A25 C11 (12)
A26 C11 (14)
A27 C11 (16)
A28 C11 (18)
A29 GND
A30 GND
A31 GND
A32 GND
B1 +5V
B2 +5V
B3 +5V
B4 +5V
B5 B9 (18)
B6 B9 (3)
B7 B9 (16)
B8 B9 (5)
B9 B9 (14)
B10 B9 (7)
B11 B9 (12)
B12 B9 (9)
B13 B10 (18)
B14 B10 (3)
B15 B10 (16)
B16 B10 (5)
B17 B10 (14)
B18 B10 (7)
B19 B10 (12)
B20 B10 (9)
B21 B11 (18)
B22 B11 (3)
B23 B11 (16)
B24 B11 (5)
B25 PRO-C0 (72)
B26 PRO-C0 (74)
B27 PRO-C0 (75)
B28 PRO-C0 (73)
B29 GND
B30 GND
B31 GND
B32 GND
The ICs:
B7 = 74AS245
B8 = 74AS245
B9 = 74HC244
B10 = 74HC244
B11 = 74AS244
C11 = 74AS244
------------------------------
CN8
A1 +5V
A2 +5V
A3 +5V
A4 SC2 (15), PRO-CT0 (15)
A5 SC2 (13), PRO-CT0 (16)
A6 SC2 (10), PRO-CT0 (21)
A7 SC2 (8), PRO-CT0 (22)
A8 SC2 (6), PRO-CT0 (23)
A9 SC2 (4), PRO-CT0 (24)
A10 NOT CONNECTED
A11 R2 (1), R3 (3)
A12 NOT CONNECTED
A13 NOT CONNECTED
A14 P1 (9)
A15 P1 (12)
A16 P1 (7)
A17 P1 (14)
A18 P1 (5)
A19 P1 (16)
A20 P1 (3)
A21 P1 (18)
A22 R1 (9)
A23 R1 (12)
A24 R1 (7)
A25 R1 (14)
A26 R1 (5)
A27 R1 (16)
A28 R1 (3)
A29 R1 (18)
A30 GND
A31 GND
A32 GND
B1 +5V
B2 +5V
B3 +5V
B4 SC2 (14), PRO-CT0 (19)
B5 SC2 (12), PRO-CT0 (20)
B6 SC2 (9), PRO-CT0 (25)
B7 SC2 (7), PRO-CT0 (26)
B8 SC2 (5), PRO-CT0 (27)
B9 SC2 (3), PRO-CT0 (28)
B10 SFIX (13)
B11 SFIX (14)
B12 SFIX (15)
B13 SFIX (17)
B14 SFIX (18)
B15 SFIX (19)
B16 SFIX (20)
B17 SFIX (21)
B18 R3 (12)
B19 R3 (14)
B20 R3 (16)
B21 R3 (18)
B22 R2 (11)
B23 R2 (12)
B24 R2 (13)
B25 R2 (14)
B26 R2 (15)
B27 R2 (16)
B28 R2 (17)
B29 R2 (18)
B30 GND
B31 GND
B32 GND
The ICs:
P1 = 74AS244
R1 = 74AS244
R2 = 74AS245
R3 = 74AS244
------------------------------
CN9
A1 +5V
A2 +5V
A3 +5V
A4 R11 (9)
A5 R11 (12)
A6 R11 (7)
A7 R11 (14)
A8 R11 (5)
A9 R11 (16)
A10 R11 (3)
A11 R11 (18)
A12 R10 (9)
A13 R10 (12)
A14 R10 (7)
A15 R10 (14)
A16 R10 (5)
A17 R10 (16)
A18 R10 (3)
A19 R10 (18)
A20 SC1 (19), PRO-CT0 (59)
A21 SC1 (17), PRO-CT0 (60)
A22 SC1 (15), PRO-CT0 (61)
A23 SC1 (13), PRO-CT0 (62)
A24 SC1 (10), PRO-CT0 (5)
A25 SC1 (8), PRO-CT0 (6)
A26 SC1 (6), PRO-CT0 (7)
A27 SC1 (4), PRO-CT0 (8)
A28 SC2 (19), PRO-CT0 (13)
A29 SC2 (17), PRO-CT0 (14)
A30 GND
A31 GND
A32 GND
B1 +5V
B2 +5V
B3 +5V
B4 P11 (9)
B5 P11 (12)
B6 P11 (7)
B7 P11 (14)
B8 P11 (5)
B9 P11 (16)
B10 P11 (3)
B11 P11 (18)
B12 P10 (9)
B13 P10 (12)
B14 P10 (7)
B15 P10 (14)
B16 P10 (5)
B17 P10 (16)
B18 P10 (3)
B19 P10 (18)
B20 SC1 (18), PRO-CT0 (1)
B21 SC1 (16), PRO-CT0 (2)
B22 SC1 (14), PRO-CT0 (3)
B23 SC1 (12), PRO-CT0 (4)
B24 SC1 (9), PRO-CT0 (9)
B25 SC1 (7), PRO-CT0 (10)
B26 SC1 (5), PRO-CT0 (11)
B27 SC1 (3), PRO-CT0 (12)
B28 SC2 (18), PRO-CT0 (17)
B29 SC2 (16), PRO-CT0 (18)
B30 GND
B31 GND
B32 GND
The ICs:
R10 = 74LS244
R11 = 74LS244
P10 = 74LS244
P11 = 74LS244
------------------------------
CN11
A1 +5V
A2 +5V
A3 +5V
A4 +5V
A5 F2 (14)
A6 F2 (12)
A7 F2 (9)
A8 F2 (7)
A9 F2 (3)
A10 F2 (5)
A11 G2 (5)
A12 G2 (16)
A13 G2 (9)
A14 G2 (12)
A15 G2 (7)
A16 G2 (14)
A17 G2 (18)
A18 G2 (3)
A19 F2 (16)
A20 NOT CONNECTED
A21 B11 (14)
A22 G10 (13)
A23 NOT CONNECTED
A24 NOT CONNECTED
A25 NOT CONNECTED
A26 NOT CONNECTED
A27 NOT CONNECTED
A28 NOT CONNECTED
A29 GND
A30 GND
A31 GND
A32 GND
B1 +5V
B2 +5V
B3 +5V
B4 +5V
B5 F1 (9)
B6 F1 (8)
B7 F1 (7)
B8 F1 (6)
B9 F1 (5)
B10 F1 (4)
B11 F1 (3)
B12 F1 (2)
B13 G1 (9)
B14 G1 (8)
B15 G1 (7)
B16 G1 (6)
B17 G1 (5)
B18 G1 (4)
B19 G1 (3)
B20 G1 (2)
B21 B11 (7)
B22 B11 (12)
B23 B11 (9)
B24 NOT CONNECTED
B25 NOT CONNECTED
B26 NOT CONNECTED
B27 NOT CONNECTED
B28 NOT CONNECTED
B29 GND
B30 GND
B31 GND
B32 GND
The ICs:
B11 = 74AS244
F1 = 74LS245
F2 = 74LS244
G1 = 74LS245
G2 = 74LS244
G10 = LS138
------------------------------
Last edited: