Holas,
channelmaniac:
Model: MV2F
Symptom: Vertical lines in backgrounds
Pin 16 (D3 for Slot 2) on the NE0-257 IC at J2 was shorted to ground. Removed the IC and checked the trace on the board. The short was gone and was internal to the chip. Replaced the chip and tested the board.
channelmaniac:
Model: MVS MV-2
Symptom: Vertical bars through graphics
This 2 slot had some bad battery damage and vertical bars through the Neo Geo logo and certain sprites.
Checked the ROM Data Lines on the cart slot pins A19/B19 through A26/B26 with the logic probe. Cart was working fine. Followed the traces to the NEO-257 IC at J2 with the logic probe. Traces were good. Followed the outputs of the NEO-257 IC to the NEO-ZMC2 IC. Two of the data lines (D0 and D1) were missing from the NEO-257.
Replaced the surface mount NEO-257 IC at J2 with one pulled from a parts board to fix.
Cleaned the board & replaced the battery as well.
channelmaniac:
Model: MV2F
Symptoms: Vertical lines on both slots
Board had a leaking battery. Cleaned up the battery corrosion and jumpered 2 traces between the NEO-257 and the NEO-ZMC2 ICs to fix slot 1. Jumpered a bad trace between slot 2 and the NEO-257 IC to fix slot 2. Installed a new battery and tested.
channelmaniac:
Model: MV2F
Symptom: Low audio on one channel and lines on screen
Battery was leaking. Removed battery, cleaned board, and installed cap kit to fix audio issue. Replaced bad NEO-257 IC to fix lines on screen. Installed new battery and tested.
channelmaniac:
Model: MV-2
Symptom: vertical lines in game
Board had a leaking battery that caused trace damage. Jumpered 2 bad traces between the NE0-ZMC2 and the NE0-257 IC, replaced the bad battery, and tested.
channelmaniac:
Here's the NEO-257 @ location J2 on the 2 slot board. (MV-2)
Code:
Pin - function/chip connection/slot connection (cartridge pin function)
1 - Slot 2 B26 (CA15)
2 - Gnd
3 - Gnd
4 - Slot 1 A19 (CA0)
5 - Slot 2 A19 (CA0)
6 - Slot 1 B19 (CA1)
7 - Slot 2 B19 (CA1)
8 - ZMC2 - 15 C0 (CA0)
9 - ZMC2 - 19 C4 (CA1)
10 - Gnd
11 - ZMC2 - 16 C1 (CA2)
12 - ZMC2 - 20 C5 (CA3)
13 - Slot 1 A20 (CA2)
14 - Slot 2 A20 (CA2)
15 - Slot 1 B20 (CA3)
16 - Slot 2 B20 (CA3)
17 - Input (Slot) Select 1/2
18 - Gnd
19 - Slot 1 A21 (CA4)
20 - Slot 2 A21 (CA4)
21 - Slot 1 B21 (CA5)
22 - Slot 2 B21 (CA5)
23 - ZMC2 - 17 C2 (CA4)
24 - ZMC2 - 21 C6 (CA5)
25 - Gnd
26 - Vcc
27 - ZMC2 - 18 C3 (CA6)
28 - ZMC2 - 22 C7 (CA7)
29 - Slot 1 A22 (CA6)
30 - Slot 2 A22 (CA6)
31 - Slot 2 B22 (CA7)
32 - Slot 2 B22 (CA7)
33 - Gnd
34 - Gnd
35 - Vcc
36 - Slot 1 A23 (CA8)
37 - Slot 2 A23 (CA8)
38 - Slot 1 B23 (CA9)
39 - Slot 2 B23 (CA9)
40 - ZMC2 - 24 C8 (CA8)
41 - ZMC2 - 28 C12 (CA9)
42 - Gnd
43 - ZMC2 - 25 C9 (CA10)
44 - ZMC2 - 29 C13 (CA11)
45 - Slot 1 A24 (CA10)
46 - Slot 2 A24 (CA10)
47 - Slot 1 B24 (CA11)
48 - Slot 2 B24 (CA11)
49 - NC
50 - NC
51 - Slot 1 A25 (CA12)
52 - Slot 2 A25 (CA12)
53 - Slot 1 B25 (CA13)
54 - Slot 2 B25 (CA13)
55 - ZMC2 - 26 C10 (CA12)
56 - ZMC2 - 30 C14 (CA13)
57 - Gnd
58 - Vcc
59 - ZMC2 - 27 C11 (CA14)
60 - ZMC2 - 31 C15 (CA15)
61 - NC
62 - Slot 1 A26 (CA14)
63 - Slot 2 A26 (CA14)
64 - Slot 1 B26 (CA15)
Un saludo
