Resoldered M1 and V chips, still no sound? MVS Metal Slug

[mmmonkey]

Picked up a cheap copy of Metal Slug which had no sound. Thought it would be an simple case of dry solder on the M1 chip.

Opened the cart up, it's using PROGBK1 and CHA256B (mvs scans and JNX both say CHA256, but mention it might use a later board). The boards are legit, with the correct Toshiba Chips, and sure enough, M1 had a few legs where the soldering looked suspect, too much solder on there and a couple of marks on the board next to those legs.

I sucked the solder off, checked for broken traces (none) and then soldered the legs again, then reflowed each remaining leg. Seeing as it's just 2 V chips, I quickly heated up each leg to let the solder reflow.

Did a quick continuity check to see if the relevant pins were connected to +5v (32) and GND (16) (after looking at datasheet on http://pdf1.alldatasheet.com/datasheet-pdf/view/115079/TOSHIBA/TC531001CP-12.html)

Still no sound. Cart passes check in Unibios if that makes a difference (forgot to check this before, so not sure if it's significant).

I guess the next step is remove the M1 chip, and look trace where each leg actually goes, so I can check continuity on each leg?

Have I missed something? Could the M1 chip be faulty - I don't have a logic pulse tester, just a basic multimeter with continuity tester. (found this thread with a faulty M1 chip - http://www.neo-geo.com/forums/showt...und-on-Last-Blade-2&highlight=sound+solder+m1)

I also don't have another copy of the cart, so can't try mixing the boards up to narrow it down.

Grateful for any advice.

ta
Pete

 

[Xian Xi]

Could possibly be the Neo-PCM on the prog board if you get no sound at all.

If you have an eprom reader then verify the V and M roms. If they are good then check continuity from the PCM to the YM2610.

 

[mmmonkey]

Cheers, I'll pop them off and have a look. I have an old Willem programmer, will investigate to see what chips I have to tell it I have to get it to read them. I guess if needed to replace the ROMS, which EPROMS would I need to purchase? On my phone right now, but will try and find out later.

Ta
Pete

 

[Xian Xi]

If the V roms are bad then you will need to split them into 4 V roms since 27C322s only run in 16 bit mode and the V roms are in 8 bit mode. So you would use 27C160 x 4. I think you can hack the 322s from what Kyuusakuu said.

 

[MKL]

Check this:

M1

1	VPP	+5V
2	A16	J3, NEO-ZMC (7)
3	A15	NEO-ZMC (5)
4	A12	NEO-ZMC (2)
5	A7	A50
6	A6	A49
7	A5	A48
8	A4	A47
9	A3	A46
10	A2	A45
11	A1	A44
12	A0	NEO-ZMC (15), A43
13	D0	B51
14	D1	B52
15	D2	B53
16	GND	GND
17	D3	B54
18	D4	B55
19	D5	B56
20	D6	B57
21	D7	B58
22	E	GND
23	A10	A53, NEO-ZMC (16)
24	G	J2, LS139 (12)
25	A11	NEO-ZMC (1)
26	A9	A52, NEO-ZMC (17)
27	A8	A51, NEO-ZMC (19)
28	A13	NEO-ZMC (3)
29	A14	NEO-ZMC (4)
30	A17	NEO-ZMC (8)
31	P	+5V
32	VCC	+5V

and this:

NEO-ZMC

1	M1 (25)
2	M1 (4)
3	M1 (28)
4	M1 (29)
5	M1 (3)
6	GND
7	M1 (2)
8	M1 (30)
9
10
11
12
13	B47
14	A44, M1 (11)
15	A43, M1 (12) 
16	A53, M1 (23) 
17	A52, M1 (26)
18	VCC
19	A51, M1 (27)
20	A58
21	A57
22	A56
23	A55
24	A54

 

[mmmonkey]

Excellent, thanks guys - brilliant info. Something else has just reared it's ugly head and i doubt i'll get a chance to be able to investigate this again anytime soon.

ta
Pete

 

[distropia]

MKL is an incredible source of knowledge. He should make a macro-wiki
If it helps, I've noticed that sometimes the mask roms (specially Toshiba ones) can have a very small crack on its center showing that rom is dead.

 

[Xian Xi]

Also sometimes it will show a brown square right in the middle.

 

[mmmonkey]

That's good to know also :-)

 

[dragonpt]

lol

i was about to buy that mvs card on ebay, after asking the seller, he told me that the sound pcb, was damage, after going into water ....

best of luck to you mate

 

[mmmonkey]

Ah well, live and learn lol! He had a few for sale, I'm convincing myself it's a diff one ;-)

Be a nice project when I get the tine again

 

[neo-geo-mvs]

lol

i was about to buy that mvs card on ebay, after asking the seller, he told me that the sound pcb, was damage, after going into water ....

best of luck to you mate

Which ebay seller are you referring to?

 

[Xian Xi]

Water doesn't damage the boards. It only damages them if you apply voltage and the board isn't completely dry yet. You'd most likely fry the LS139 before the roms.

 

[dragonpt]

Which ebay seller are you referring to?

dont remember, and i deleted my pm messages, but i saw that on irland/uk ebay about an week or two ago, and was about 20£ i think....

 

[dragonpt]

Water doesn't damage the boards. It only damages them if you apply voltage and the board isn't completely dry yet. You'd most likely fry the LS139 before the roms.

maybe he can get an replacement ls139 chip/ or similar

 

[Xian Xi]

maybe he can get an replacement ls139 chip/ or similar

He can but that's assuming the LS139 is bad.

 

[neo-geo-mvs]

dont remember, and i deleted my pm messages, but i saw that on irland/uk ebay about an week or two ago, and was about 20£ i think....

Well the one Pete is talking about is the one I sold him. I've not received any messages from you about the game:

http://www.ebay.co.uk/itm/Metal-Slug-Neo-Geo-MVS-Game-Cartridge-/320737605997?pt=UK_Video_Games_Coin_Operated_MJ&hash=item4aad73796d

When I buy games I'm not given the history of what's happened to the cart. The cart is sold to me as working - to me this means that the game should have both the sound and graphics working. On occassion the games I get are not as described - i.e. problem with the sound/graphics. Therefore I sell the game on as faulty. No point in lying and disappointing the buyer by saying the game is perfect working order if it's not! Honesty is the best policy!

More pics at:

http://s869.photobucket.com/albums/ab258/meechand/Metal%20Slug%20no%20sound/

 

[mmmonkey]

blimey, there's been a fair few replies. Yep, I bought it from neo-geo-mvs and like he says, he's an ebay seller that is honest about the condition of items etc. had a few bad experiences on there recently.

Still not had a chance to investigate further. hoping to get a look over the next few weeks

 

[dragonpt]

well i can see its NOT the same auction, the other Metal slug had an white case (bootleg?)

hope to see this sound card, working again, in all his glory

ps: my 4 slot just arrive xD time for testing now.........

 

[mmmonkey]

Checked continuity from M1 and Neo-ZMC last night, all fine. I think next i'll see if I can pickup another cart to swap boards over to see which board I should be concentrating on, see if I can eliminate one or the other before I go desoldering ROMS to dump etc.

Priorities changed now, so if I get spare time, it's spent with a control pad in my hand rather than a soldering iron!

Pete

 

[mmmonkey]

spamming my own thread now. Also checked the PCM to the cart connectors following this from your site Xian Xi, all tested fine.

A41 - NC
A42 - NC
A43 - YM2610 (41) -> NEO-PCM (57)
A44 - YM2610 (42) -> NEO-PCM (58)
A45 - YM2610 (43) -> NEO-PCM (59)
A46 - YM2610 (44) -> NEO-PCM (60)
A47 - YM2610 (47) -> NEO-PCM (61)
A48 - YM2610 (46) -> NEO-PCM (63)
A49 - YM2610 (16) -> NEO-PCM (38)
A50 - YM2610 (23) -> NEO-PCM (39)
A51 - YM2610 (22) -> NEO-PCM (40)
A52 - YM2610 (35) -> NEO-PCM (41)
A53 - YM2610 (36) -> NEO-PCM (42)
A54 - YM2610 (38) -> NEO-PCM (44)
A55 - YM2610 (20) -> NEO-PCM (45)
A56 - YM2610 (21) -> NEO-PCM (46)

B41 - YM2610 (48) -> NEO-PCM (48)
B42 - YM2610 (49) -> NEO-PCM (49)
B43 - YM2610 (50) -> NEO-PCM (50)
B44 - YM2610 (51) -> NEO-PCM (51)
B45 - YM2610 (52) -> NEO-PCM (53)
B46 - YM2610 (53) -> NEO-PCM (54)
B47 - YM2610 (54) -> NEO-PCM (55)
B48 - YM2610 (55) -> NEO-PCM (56)
B49 - YM2610 (17) -> NEO-PCM (28)
B50 - YM2610 (16) -> NEO-PCM (29)
B51 - YM2610 (15) -> NEO-PCM (30)
B52 - YM2610 (14) -> NEO-PCM (31)
B53 - YM2610 (13) -> NEO-PCM (34)
B54 - YM2610 (12) -> NEO-PCM (35)
B55 - YM2610 (11) -> NEO-PCM (36)
B56 - YM2610 (10) -> NEO-PCM (37)

 

[Xian Xi]

You don't have a logic probe? You need to get one dude, its quite useful.

 

[mmmonkey]

It's on my wish list, should get one really. The missus doesn't see things like that as suitable presents for some reason?!

 

[CafeineCake]

You can probably knock one out with stuff around:
http://www.swansontec.com/sprobe.html

 

[mmmonkey]

The other day I received a working MS cart, so thought I would narrow down the fault a bit further by swapping the boards over. It's the CHA256B board that's the problem so thought I'd have another look at the M1 chip. Still don't have a logic probe, so decided to desolder and dump the M1 ROM. Downloaded and used Hexprobe to do a compare and it found a few differences - I'm guessing they should be exactly the same? (click to see full size)