X68000 Expert graphics glitch. Any ideas?

[TheRealAnubis]

Hi all,

I have an X68000 Expert that's having some strange graphic issues, and only on this game as far as I can tell.  When I was first loading the game with floppies, the graphics were there, but the game wouldn't make it to the start screen.  After trying a few different ROM sets, I got it to load, but now there are graphics missing - in the intro, and in the game.  It's like the background goes away sometimes and there is just black screen, but then other places the background is visible.

The game is Mahou Daisakusen.  I'm using an AztecMonster in this video to load the game, with the same results as loading from the floppy drives.  This setup was tested and working fine in another Expert.

Video of missing intro graphics

Sorry it's not the best quality, but you get the idea of the problem.

Not sure if it's unrelated or not, but when using the AztecMonster and the public V3 or V4 image, ChoRenSha wouldn't load without additional RAM installed in the machine, although it loads fine from the floppy drive.  Does the SASI loader take up RAM on boot?

Also - if anyone has any high res pictures of the Expert motherboard, that would help me in looking up the parts and availability for repairs.


Thanks!

[SuperDeadite]

Mahou looks like bad disks to me.
Honestly Mahou pretty much requires 16mhz, and an 030 is highly recommended.  On an Expert it wont be much fun...

Cho needs 2mbs to boot.  I assume you only have 2mbs in your machine.  Try quitting LHES and running it directly from the prompt, as LHES does stay in ram.

[TheRealAnubis]

Hi,

I thought that was the deal as well, but it does the same thing with floppies, or from an AztecMonster that's been tested on another machine and is working.  Different images/disks, etc.

I tried setting to the lowest levels and it seemed to play ok, as long as you don't mind missing backgrounds most of the time.

I'll give it a try by quitting to the prompt and running from there - I'll have to pull the RAM card and reset the value in switch as well..

Thanks for the tip!

Still wondering about the missing graphics though - they were there once, then within an hour or so of trying to get a good set of floppies to work (before I had the Aztec) they just disappeared.  At that point, the 2nd floppy drive was acting strange (bad formats, etc.) so I recapped it with tantalum caps, and now it's solid, but still the same problem with the game..

I guess my main concern is if there's a problem with the video RAM, or something like that, this could possibly happen in other games.  Now is the time for me to either pull it apart and attempt repairs, or not worry about it.

[eidis]

 Hi TheRealAnubis !

Try running Mtest and please post the results.

Memory Test for X68000
http://nfggames.com/forum2/index.php?topic=4810.msg31557#msg31557

Keep the scene alive !
Eidis

[TheRealAnubis]

Hi,

I ran memtest68k overnight with no errors - I'll give this a try next.  Thanks!

[TheRealAnubis]

Ok, all tests passed  except the system memory -m switch.

I popped out the ram card and fixed the ram size with switch with same result - the following message:

UPDATE!  Just ran this from image at prompt and now it will run the main memory test!

It passed with an OK and another  message.

[hyperneogeo]

First pic says: Please remove console driver

Second pic says: Completed, please reset

[eidis]

 Hi TheRealAnubis !

Did you recap the whole system ? If not then that is a must. The problem could also be linked either to faulty capacitors or a broken/corroded trace somewhere.

Keep the scene alive !
Eidis

[TheRealAnubis]

Hi,

No full recap.  I replaced the PS with a Pico PS, and recapped the 2nd drive.  I'll see what I can do about getting it apart and having a look at the mobo.

Also, thanks for the message decoding!   

[TheRealAnubis]

Well, I've got it apart - very few caps on the mobo.   I'm thinking that one of the video ram chips is faulty, but maybe not bad enough to trip the mem testers.   Traces all look clean and intact.
Does anyone have a schematic for the Expert that I could take a look at.  There are several types of ram on the mobo.

My model is a cz-602c

Thanks!