Diagnostic cartridge issues MSTE

[Dbug]

Question: I just received my diagnostic cartridge for my Mega STe, but when I try it I get some red screen with "Bus Error" and "Bad Instruction Fetch" messages scrolling.

When I try GemBench configuration I get a file on the cartridge which I can launch from the desktop... and it crashes.

But the YAART program from the very same cartridge seem to be working just fine, so my theory that maybe my expansion cartridge port is defective seems to be incorrect, any idea what could cause the rest to not work?

[exxos]

Clean the cartridge and the port with IPA and see...

Does it pass running RAM tests with YAART ?

[Dbug]

Clean the cartridge and the port with IPA and see...

Does it pass running RAM tests with YAART ?

Yes, I let it run for about one hour, guess about 13 passes, no errors, with various vertical patterns on screen.

I'll try the cleaning.

[Dbug]

Cleaning did not help, same behavior.
Is it possible the content of the eprom/flash got somewhat partially corrupted?

[exxos]

Is it possible the content of the eprom/flash got somewhat partially corrupted?

Not really.. They are all verified.

You could resolder the socket in case there is a bad joint. Otherwise I don't know why some programs run and no others. If it was a ST I've seen odd things happen when the bus resistors have not been changed.

[frank.lukas]

Contact problems in the cpu plcc socket maybe ...

[rubber_jonnie]

Just to ask an obvious question here, have you definitely got the jumpers set for MSTE and not something else?

[Dbug]

Just to ask an obvious question here, have you definitely got the jumpers set for MSTE and not something else?

I got confused originally because the right block of three pins is not aligned like the left one in regard to what's printed on the PCB, but as far as I've figured out that should be correct?

image_2021-09-24_141501.png

Contact problems in the cpu plcc socket maybe ...

If that was the case, I would assume the memory test (and the actual machine when the card is not connected) would not work either?

That being said, I do have a problem with the machine (which is why I got the diagnostic card in first place): I bought a MonSTer card, and when it's installed the Blitter is not working (and yes, I did the 5 wire solders on the two chips).

You could resolder the socket in case there is a bad joint. Otherwise I don't know why some programs run and no others. If it was a ST I've seen odd things happen when the bus resistors have not been changed.

As far as I can see, there's no obvious problem with the solders on the diagnostic cartridge.

Regarding the bus resistors, what/where/how should I test? This machine never had any recapping or fixes done, but I've installed a TOS 2.06 UK on it (it had a 2.05 originally) and a 1.44 MB floppy drive.


I do have a few other cartridges I could try on the machine to see if the expansion port itself is working fine:
- A Steinberg dongles for musical software
- A Netusb peripheral
if they work, could we assume the port is fine?

[exxos]

That being said, I do have a problem with the machine (which is why I got the diagnostic card in first place): I bought a MonSTer card, and when it's installed the Blitter is not working (and yes, I did the 5 wire solders on the two chips).

I would suggest you take the machine "back to stock" and try the cartridge then. Otherwise if the MonSTer card is causing problems, you should contact AlanH about it ( I do not believe he is a member on here).

[Dbug]

I would suggest you take the machine "back to stock" and try the cartridge then. Otherwise if the MonSTer card is causing problems, you should contact AlanH about it ( I do not believe he is a member on here).

Oh, sorry I was not clear: The MonSTer was already removed (as well as the VME graphic card and the Ultra Satan), right now it's stock, other than the TOS and Floppy version.

I wanted to test without to get a proper baseline and see if the diagnostic card would find anything weird on the machine before I attempt to get the MonSTer to work again.