Repairing MVS carts with 64mbit proms

[distropia]

Hi. I have some MVS carts for repair. One is a Metal Slug 2 and one rom in the "cha board" has been phisically damaged. The rom is a Toshiba TC5364205AP (64mbit) and I can't find any equivalent eprom. Same happens with a Strikers1945+.
I have been looking on internet, on ebay, even on chinese webs but nothing. No datasheet for that Toshiba OTP roms, no equivalent...

What rom/eprom/whatever should I use? Or there's no replacement for that!?

BTW: my programmer is a wellon vp280

Thank you, guys!

 

[Xian Xi]

As far as I know the biggest eprom is 32Mbit. If the CHA still has empty slots you can split the rom image but I don't know about the jumper settings.

 

[Kyuusaku]

Yeah either put two 32M ROMs side by side (if possible) and rewire the decoding (you just need a 74139 or even 7400) or stack one on top of the other (of course don't short /CE or /OE, whichever the PCB uses for decoding). If the PCB decodes the ROM with /CE, attach your decode circuit to /CE, if it uses /OE attach circuit to /OE. If you want to use a 7400 instead of 139 here's the decoder:

 

[distropia]

Wow, thank you very much for your quick responses!
Maybe I can have some trouble stacking two 27c322 'cause of the separation between pcb's inside the cart... Anyways I'll try it.

For cleanliness and keeping the cart as closer as it was originally, I've seen the original blank toshiba proms on chinese websites, but my programmer is unable to write them. Even the biggest wellon vp980 can't. It could be the perfect solution but they do not show the price, and I guess they only sells high amounts of chips.

Don't you know any macronix chip equivalent to 64mbit (or any other brand)?

thank you, guys

 

[distropia]

Right now I've found the macronix MX26L6420 that seems to be ALMOST pin-to-pin compatible with that toshiba TC5364202AP or 205AP oldies. But it is 44pin instead 42 pin.
Anyways it is impossible to find that 64mbit toshiba pinout, I've compared with the nearer tc538200 (8mbit).

 

[Kyuusaku]

Why do you think it's a PROM instead of a mask ROM? The pinout should be easy to find, I'm sure it's online.

 

[distropia]

Yes, sorry I meant "mask rom" instead prom.
Unfortunately, if you google for "tc5364202ap" (found in Strikers1945) there's ZERO results. I've been deeply looking for it on alldatasheets.com but nothing. Same with the tc5364205ap that can be the same with some minor changes.

Nobody has repaired this kind of cart? Don't even wanna think about one "prehistoric isle 2" that I grabbed with 4 bad mask roms... No space at all for splitting the image onto 2 eproms!
I don't give up easily. By now I'll try the Kyuusaku solution (thanks again!) but the proper way should be using only one chip.

 

[distropia]

As I said before, I don't give up easily. Specially if I have some valuable carts with several tc5364205 broken chips.
If anyone is interested, I found this "thing" on a bootleg cart. This "thing" is like a 64mbit chip but made of 4 smd chips.

Behind that there's another 2 chips.
Now, I don't know if this thing is somewhat compatible with my programmer, or if I would have to desolder each chip and burn an 1/4 of the original rom in each one...
Some ideas?
(btw: thanks)

 

[distropia]

I'm monopolizing this thread
In another cart, i got this problem:

It is a Shock Troopers 2nd Squad that I got without the prog board. I made one from a BK1 board that I had. I set all the jumpers for the new 16mb P1 with image doubled instead the original 8mb. I copied the jumpers from http://mvs.gotwalls.com/index.php/File:Last_blade_set2_b1_front.jpg
This BK1 is the same as mine but for the V3 & V4 (upper jumper for 32mbit V, lower for 16mbit one, no jumper = no chip).
I tried it, but got a black screen with some red bar, but inserting credits it changed and moved. It looked like the S1 chip was fryed. In fact, I swapped the original S1 by a new 27c010 with swapped pins 2 and 24 (remember S1 is non-jedec compliant) and it showed the above images.
What do you thing, guys?

 

[Xian Xi]

As I said before, I don't give up easily. Specially if I have some valuable carts with several tc5364205 broken chips.
If anyone is interested, I found this "thing" on a bootleg cart. This "thing" is like a 64mbit chip but made of 4 smd chips.

Behind that there's another 2 chips.
Now, I don't know if this thing is somewhat compatible with my programmer, or if I would have to desolder each chip and burn an 1/4 of the original rom in each one...
Some ideas?
(btw: thanks)

Well for the cost of the adapters, chips and shipping it would be a waste of money for a Metal Slug 2 cart. Another one can be had for much cheaper.

I'm monopolizing this thread
In another cart, i got this problem:

It is a Shock Troopers 2nd Squad that I got without the prog board. I made one from a BK1 board that I had. I set all the jumpers for the new 16mb P1 with image doubled instead the original 8mb. I copied the jumpers from http://mvs.gotwalls.com/index.php/File:Last_blade_set2_b1_front.jpg
This BK1 is the same as mine but for the V3 & V4 (upper jumper for 32mbit V, lower for 16mbit one, no jumper = no chip).
I tried it, but got a black screen with some red bar, but inserting credits it changed and moved. It looked like the S1 chip was fryed. In fact, I swapped the original S1 by a new 27c010 with swapped pins 2 and 24 (remember S1 is non-jedec compliant) and it showed the above images.
What do you thing, guys?

If you are using a 27C010 for the S1 then you don't need to swap pins. If you are using a 27C100 then you do need to swap pins to use as an S1.

 

[distropia]

About the 64mbit chip, I'm trying to find the best and cheaper way to repair not only MS2, but strikers1945, metalX, prehistoric isle and another valuable carts that I got for $3/each.

About the Shock Troopers 2, I have tried swapping the pins to the original position and nothing changed The same image.

 

[Xian Xi]

Check the traces for the S1 on the back of the CHA board near the tower mount hole. There are traces that get rubbed and cut over there all the time.

For the 64Mbit games you can buy the adapters and chips from buyicnow.com, if you don't have a suitable programmer he can program them for you with whatever file you want for I think $0.50 each chip. The adapters are 44 pin so you don't use the 2 extra pins (1 and 44). I'm unsure of any jumpers needed though.

Adapter:
http://www.buyicnow.com/fincat.php?cat=203

Chip:
http://www.buyicnow.com/fincat.php?cat=169

 

[distropia]

Great news. Thanks Xian Xi !! I even have these chips on my workbench from a bootleg cart.

The only cons that I see: these chips operate at a maximum of 3.6v and I *think* that the original boards supply 5v to every chip.

Respect to the ShockTr. cart, I always check every trace in that area (and everywhere). Thanks for the advice but the problem is in another place. I've swapped the surface mount chips with another from a supposedly working CHA board but nothing changed. I will re-swap the neo-zmc (bankswitching) and then re-check the 74LSxx chips in my programmer, but with the big neo273 I can do nothing but swap it again.
This cart is turning to be a nightmare, but I really love this game.

 

[distropia]

Sorry! The 10k resistors in the adapter are for turning 5v in 3.6v?

 

[Hewitson]

Crappy adapters if thats the case.

 

[distropia]

I've found some chinese wholesalers that have the infamous TC5364205 rom in stock. The price varies from $3 to $8 each.

Channelmaniac adviced me that some of them can be fake. I got in contact with the wholesalers and some of them assure they only sell original chips, another ones say nothing about it.

I really don't know what to do. The MX chip + adapter solution is great, but the authentic as-original repair should be using the same chips SNK used.

If someone wanna make a joint order, I will supply the wholesalers I've found.
Note: before making an order, I have to find someone with a pro chip burner capable of that chip.

 

[Xian Xi]

That's the problem though, finding a programmer that is capable of using that chip.

Either way the cart will be repaired so authenticity isn't going to be 100%.

 

[Kyuusaku]

It's a MASK ROM, remember? You can't program it and chances are the data on the used chips aren't what you need

 

[Xian Xi]

Aren't they OTP? Are they new or used?

 

[Kyuusaku]

No mask ROM aren't OTP, they are "programmed" ie hardwired at the factory.

 

[Xian Xi]

No mask ROM aren't OTP, they are "programmed" ie hardwired at the factory.

Ah I see. Thanks for the clarification.

 

[jew90]

My programmer can read that chip but you should be able to get a dump from mame.

You will need to use a programmable chip if you want to replace it with a freshly programmed chip.

If you want to use MASK rom you will have to get one from another cart that contain the same data

 

[Hewitson]

You could always get a single one made, bet that'd be cheap

 

[jew90]

You could always get a single one made, bet that'd be cheap

 

[Kyuusaku]

Oh yeah, I forgot to mention it *IS* a broken address line trace (from the NEO-273 or 7474 to the C ROMs), even though you said you checked them all this is certain.