Mega STe stability issues.

[Dbug]

Hi,
last year I had some adventures involving a diagnostic cartridge which did not work, which ended up being caused by a dead fuse on the mega ste motherboard.

Since then I managed to get my VME Card (Nova) to work, as well as the MonSTer card, with Alt Ram (where I was able to move most accessories and residents thanks to PRGFLAGS), no problems uploading or downloading files with the Netusbee using uIP-Tool, and after fixing the capacitors on the internal Ultra Satan no more boot problems, replaced the 68000 by the low power model, and just to be sure I did the full recap of the PSU using the exxos capacitor kit.

The problem now is that the machine is still not actually reliable: Most things work, and then it does not, and in weird ways (like if I try to install CAB 2.8 without the VME card enabled (boot without any residents installed), the installation works, but if I try on the standard setup, then it will fail at some random point and go back to the desktop.)

So, what I'm wondering at this point is:
- Are there any hardware upgrades/fixes I could do
- Are there any software diagnostic I could run (like a YAART memory test for Alt Ram, or VME, ... ) ?

Is it possible that when the VME card is in use, somewhat there's power problems that make the machine less reliable than when the card is not being used?

Is it possible the the Mega STe PSU is not able to provide enough clean power for all the stuff connected (Mach 32, MonSTer, Ultra Satan internal, NetUSBee) ?

This is frustrating to feel the machine to be so close from finished and then get a random 2 or 4 bombs on something than ran fine for hours the day before, and will probably run fine the day after.

Thanks for any suggestion

[Steve]

Only having one example of strange behavior makes it hard to get an idea of the issue. Especially with CAB which isn't the most straight-forward thing.

Could you do some benchmarks while NOVA is active?
Kronos, Gembench, YAART on loops to test the hardware.

Secondly the big 'red card' that comes up for me is Ultrasatan, which version are you using. Do you have the ability to try a SCSI drive instead? Reason Ultrasatan worries me is there are some dodgy versions on the market (non-Lotharek) and you're also open to DMA issues with it depending on your hardware.

[Dbug]

Only having one example of strange behavior makes it hard to get an idea of the issue.

Ok, a few more issues when I have the "full" setup active:

- The machine does not always boot correctly, most of the time it does start fine with all the startup programs, then the bee appearing in the center of the VGA screen, desktop appears, all fine. Some other time the boot sequence stops with the cursor arrow on the top left of the screen, white background, and it's frozen, have to reset and try again (which generally happens just fine)

- I tried to edit a config file using the STeno desk accessory editor, loading the filed, scrolled around with the keyboard to find the right parameter to change, pressed backspace to delete some character -> froze. Did a reset, tried again and no problem.

It's mostly this type of small failures on thigs that generally work, until they don't, and that's totally unpredictable. Happened with the case off as well (tested in case that was some overheat issue).

Could you do some benchmarks while NOVA is active?
Kronos, Gembench, YAART on loops to test the hardware.

Gembench I've left running for hours in loop mode without any problem.

Kronos does not start because apparently it does not like the graphic card (it runs fine (but visually unusable) if I run it in medium res without the card).

I've not tried YAART with Nova active, I can try that.

Secondly the big 'red card' that comes up for me is Ultrasatan, which version are you using. Do you have the ability to try a SCSI drive instead? Reason Ultrasatan worries me is there are some dodgy versions on the market (non-Lotharek) and you're also open to DMA issues with it depending on your hardware.

It's the Lotharek internal Ultra Satan 1.2 with the Mega STe internal adapter.

I recently posted a series of photos of the current setup:

[scsilord]

The ATI cards (mach32/64) are very power hungry and can cause voltage drops. I had some stability issues with a mach32 until I soldered a +5V and GND connector on the nova ISA connector board. Delivered voltage went in my case from 4.5 to 5.05.
ACSI/DMA is always a trouble maker. Shorten the ribbon cable you got from lotharek as much as possible, just make sure you can still open your drive bay to access your ultrasatan.

[Dbug]

The ATI cards (mach32/64) are very power hungry and can cause voltage drops. I had some stability issues with a mach32 until I soldered a +5V and GND connector on the nova ISA connector board. Delivered voltage went in my case from 4.5 to 5.05.

Do you have some photos/diagrams showing what you connected from where to where?
Btw, just want to mention that's an original Nova which was originally in the black plastic box, it's not one of the newly remade models.

ACSI/DMA is always a trouble maker. Shorten the ribbon cable you got from lotharek as much as possible, just make sure you can still open your drive bay to access your ultrasatan.

That should not be a problem, I can probably cut it in half without any access issue, would probably even make the inside tidier

[scsilord]

This is how i hooked up the +5V(red) and GND(black) to my ISA board. I carefully scratched away some of the paint for extra sturdiness.

IMG_20220426_110011[1].jpg (37.39 KiB) Viewed 3324 times

As a positive side effect after doing this the 1280x1024 resolution became a little sharper on a tft.

For anyone who wants to do this, please double check with a multi-meter that there are no shorts and the GND and +5V end up on the correct ISA socket pins.

[Dbug]

Thanks!
I guess before the soldering I could start by measuring the voltage and see how much I currently have in the existing setup.

[mikro]

Kronos does not start because apparently it does not like the graphic card (it runs fine (but visually unusable) if I run it in medium res without the card).

This is a red flag by itself. Kronos runs on basically everything, TOS VDI, NVDI, fVDI, mono, 16 colours, 16M colours, ...

To me it looks like your ROM may be at fault here, especially with the MonSTer in the play. I'd repeat the tests / use cases without MonSTer and see what happens. You may have some bad connectivity in the CPU socket (those PLCC sockets really suck for this kind of addons).

I once had a similar trouble with my NOVA card: https://www.atari-forum.com/viewtopic.php?t=34600 ... in the end it was caused by a bad SIMM module.

[Dbug]

Kronos does not start because apparently it does not like the graphic card (it runs fine (but visually unusable) if I run it in medium res without the card).

This is a red flag by itself. Kronos runs on basically everything, TOS VDI, NVDI, fVDI, mono, 16 colours, 16M colours, ...

So I tried again, I get the menu with "Kronos 2.50 File Tests Misc Configure", a "Prepare graphics ... please wait" box, and then I see some bombs on the shifter screen and back to desktop.

Is 2.50 the last version?

To me it looks like your ROM may be at fault here, especially with the MonSTer in the play. I'd repeat the tests / use cases without MonSTer and see what happens. You may have some bad connectivity in the CPU socket (those PLCC sockets really suck for this kind of addons).

That being said, if the issue is caused by bad power, removing the MonSTer may just be enough to make things work, despite the problem not being the MonSTer.

As you said, these sockets are flimsy, I'd rather avoid removing and adding the card too often, I guess I'll try that if the shortening of the Ultra Satan cable, and checking the +5v on the ISA card does not help.

I once had a similar trouble with my NOVA card: https://www.atari-forum.com/viewtopic.php?t=34600 ... in the end it was caused by a bad SIMM module.

YAART did not find anything regarding the 4 megs of ST Ram, and the MonSTer software did not find any error in the ALT Ram.

[Steve]

@Dbug I do not think you have a power issue, why? Because my TT has exactly the same PSU as your MegaSTE & you have re-capped it. My TT has: NOVA, Ati Mach64, Stormy RAM, Thunder IDE, Lightning VME, Internal fans x2, RaSCSI (PiZero2), Belkin powered HUB - all inside - all powered by that same PSU, all is well.

You haven't mentioned your graphics drivers yet, are you using Ideks? or NVDI's? If one, try the other ...