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SOLVED! Bonanza Bros - Not booting and Japanese Error Screen

98pacecar

98pacecar

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I've started to dig into my project Bonanza Bros cab and have done all of the basic checks. The screen I'm getting is indicating a board issue of some sort, but I'm hoping someone here has seen this before and can maybe guide me in where to start with checking. It's odd that the characters seem to be doubled up. Also, the board won't progress past this screen, even into test mode. I've tried it with 2 floppy drives and an HxC with the right image, but no change. It never seems to hit the drive. Swapped the 2 68000s just to see if it might change something, but no difference.

Any guidance before I just start probing chips would be much appreciated!

IMG_1886.jpg
 
Humm... RAM failure?
Do you have a way to probe CPUs signals and buses?
 
That was my first thought as well. I've got a fluke 9010, but no 68000 pod. So I think I'll be reduced to using a logic probe unless there's a better way.
 
As @Apocalypse said, I'd check the RAMS as this seems to be a Graphic Ram problem. Once it's checked and if they all prove to be OK, I'd check the data and address lines on the bus as well to see if any line remains stuck high or low.
 
Good luck, System 24 being originally based on floppies and floppy access being slow the whole game is loaded in RAM on boot up (takes maybe a minute) then accesses to the floppy are limited mostly to high score savings.
So my point is S24 motherboard contain a shit lot of RAM chips, totalling 1.3MB.
 
When I said address and data lines, I mean between ram and CPU :)
 
Fortunately, a buddy of mine has a 68000 pod I can use, so as long as I can figure out how the 2 CPUs share the bus, I should be able to use that to get somewhat of a start. That said, I'm not real adept at this yet so I'm likely going to just be stabbing in the dark! lol!
 
Give it a try! We need to rescue all these jewels from the trash bin. They all deserve a 2nd life :thumbsup:
 
I'm sure trying!

Spent some time with a probe just hitting the ram to see if there's activity. On all of the address pins, I do see activity as I'd expect! But the odd thing is I don't see any activity at the address pins on either CPU. One CPU shows activity for a couple of seconds on reboot, but then quickly stops. I'm guessing it's enough to get the code for the screen I'm seeing loaded and then it crashes. Never seems to reset after that.

Next step is trying to nail down where the ram signals go. Looks like the customs get involved, so this may get tricky.
 
If CPU is running code, I'd say that something is running but gets stuck somewhere. I'd check the 2nd CPU that loads the game or the Eprom with boot code (if there's any) to make sure it's not a data problem. If all that looks OK, then it should be an IC problem. Either bad contact or gone south. I'm sure @caius can shed more light here.
 
I'm not really familiar with this hardware, never got or repaired a boardset but I'd say fault is in the tilemap circuit so for first check the video RAMs.
 
Darksoft said:
If CPU is running code, I'd say that something is running but gets stuck somewhere. I'd check the 2nd CPU that loads the game or the Eprom with boot code (if there's any) to make sure it's not a data problem. If all that looks OK, then it should be an IC problem. Either bad contact or gone south. I'm sure @caius can shed more light here.
Click to expand...
Good point. I hadn't considered dumping the boot noms yet. That's a simple check to rule out a quick fix.

If those check out ok, I'll move on to the tile map hardware next.

Thanks for the advice guys! This is in a nice dedicated cab, so it would be cool to resurrect it and keep it intact.
 
Apocalypse said:
So my point is S24 motherboard contain a shit lot of RAM chips, totalling 1.3MB.
Click to expand...
Umm, so I should have paid a bit closer attention to this. There's RAM everywhere on this board!! LOL!!

I missed a set of 6 65256 that are tied to the tile map generator. Probing them, I found that A14 was held high on 4 of them. Tracked this back to a 74F373 where I found what appear to be good inputs, but the output that goes to A14 is held high. So there's a problem somewhere in this.

My question is how do I know if it's the output of this 373 that's the problem and not a RAM chip that's pulling it all high, if that's even possible. I'm going to get with my local parts guy anyway and get a replacement 373, because I suspect that's at least one problem and shouldn't be a big deal to pull and replace.
 
98pacecar said:
My question is how do I know if it's the output of this 373 that's the problem and not a RAM chip that's pulling it all high, if that's even possible. I'm going to get with my local parts guy anyway and get a replacement 373, because I suspect that's at least one problem and shouldn't be a big deal to pull and replace.
Click to expand...
You can't know, even with the use of a logic comparator as data are bussed.
That's possible a RAM pull the signal high due to internal failure but it's quite rare.
Try piggybacking a known good 373 on top of the suspected bad one. Even if that doesn't fix the board (the faulty chip can still pull the signal) have a look at the stuck signal for any activity.
 
That's what I was thinking, so I appreciate the confirmation. I'l try out the piggyback method as soon as I can get a hold of a replacement.

Thanks!!
 
Ok, pulled the 373 in question and checked the impedance across the bad pin and vcc. Didn't see low impedance like I'd have expected if that chip were bad. Checked impedance across vcc and the bad pin at the newly installed socket on the board and I still .9 ohms there. So I guess that means it's likely one of the RAM chips that's causing the issue? Unfortunately, these are not socketed so I suppose I'll just have to remove them one at a time until the problem resolves. Maybe I can desolder just the address pin that's stuck and lift it to narrow it down to the specific chip with the issue.
 
98pacecar said:
Ok, pulled the 373 in question and checked the impedance across the bad pin and vcc. Didn't see low impedance like I'd have expected if that chip were bad. Checked impedance across vcc and the bad pin at the newly installed socket on the board and I still .9 ohms there. So I guess that means it's likely one of the RAM chips that's causing the issue? Unfortunately, these are not socketed so I suppose I'll just have to remove them one at a time until the problem resolves. Maybe I can desolder just the address pin that's stuck and lift it to narrow it down to the specific chip with the issue.
Click to expand...
Check for any bent pin that would make contact to Vcc.
To find the least point of resistance you need a milli-ohmetre.
 
You beat me to it. I was staring at the back of the board and noticed that a couple of pins were shorted between 2 of the RAM chips. Fixed that, put the 373 back in, and the board fired up!

Now, I'm just fighting the HxC to get it to work. But at least I'm making progress!!
 
98pacecar said:
You beat me to it. I was staring at the back of the board and noticed that a couple of pins were shorted between 2 of the RAM chips. Fixed that, put the 373 back in, and the board fired up!

Now, I'm just fighting the HxC to get it to work. But at least I'm making progress!!
Click to expand...
You must edit the HXCSDFE.CFG file and set pin 2 low and pin 34 high. Then place the file at the root of the SD cart with the .hfe files you converted from .s24 (just rename MAME's .img files to .s24).
 
I had found that part on the HxC forum, but still no luck. I'm switching over to a Windows PC instead of my Mac to see if that's an issue.

Put the beta firmware on the unit as well. It will hit track 1 and then pause, which seems to be somewhat common.

Edit: Looks like the Windows PC may have been the trick. I have played my first game of Bonanza Bros!

Turned out I just had a short on the board, but didn't notice it until I got it at just the right angle. None of the real floppy drives/disks I have are good, but it's working with the HxC so that's even better.

Thanks to Apocalpyse, Darksoft, and Caius for the assistance. I couldn't have done it without you guys!!! Next time any of you make it to Dallas, I owe you a good Texas beer!
 

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