SE/30 with DayStar Turbo 040 Struggles

[jasonfortheworld]

So I decided to just see what happens with the SE/30 board that can't boot properly. I get stuck at the question mark floppy screen, but I can move the mouse normally.

I added the Bolle adapter, the Turbo040, 4x1mb of RAM, and the stock SE/30 ROM to the damaged board and booted.

To my surprise, I was able to get to the question mark screen and move the mouse around. Now, this may not be definitive proof as I have no idea what's wrong with the broken board, but I'd say that strongly suggests the Logic Board of my original SE/30 may have underlying issues I haven't discovered that are messing with the use of the Turbo040.

Now I just need to figure out my next step to troubleshoot the original SE/30 logic board.

 

[jasonfortheworld]

So while progress hasn't been made, I was able to confirm that my logic board has some kind of underlying issue with it.

With the wonderful help of @AEChadwick I was able to use my Bolle riser and Turbo 040 on his SE/30 without any issue at all.

But that means I'm officially out of my comfort zone. I have zero skill with hunting down logic issues like this, so I'll need to find someone who's able and willing to take a look at this board.

 

[eharmon]

I'm finally getting back around to trying to see why my Turbo 040 is intermittent in my SE/30, and this thread nearly matches my experience.

I've got pretty much the same setup. I'm running Bolle's Combo card with a firmware 4.11 Turbo 040 (ASIC version with onboard cache). I've returned everything to stock (standard ROM) minus the PRAM battery.

Unlike the original post here, I can, occasionally, get the system to boot. I see the Turbo 040 happy Mac, and the system starts searching for SCSI devices. If I reboot from that state, it'll keep working.

However, if I flip the power off, it's back to failing to boot. When it's failing, I'm getting the simasimac, so no code execution at all.

With just a ComboCard, or a ComboCard and zzg's 30video on board, the system works great. Extremely reliable and boots 100% of the time.

Since it works, randomly (but very rarely), my only guess is inrush current is dropping the voltages too low momentarily? Or perhaps very specific logic boards are incompatible with the Combo card? (For that, I'm curious to compare notes on board revision information @jasonfortheworld)

Any other ideas where to look?