[SE30] Repair in progress

[genie_mac]

Has anyone ever actually got the diagnostics mode to work on a SE/30?

I have been trying to get a response from a couple of SE/30 boards (both working and non-working) but no luck. I tried both the onboard serial ports and also the transmit/receive signals on the diags header on the logic board. I read that the machine should blank the screen but it boots just normally even though PA0 of VIA1 is pulled low.

Let us know if anyone has this working on a SE/30.

Cheers!

 

[Sebastian]

Today new video-RAM arrived (brand new), i soldered it in and got a ...

...

...

Classic simasi-mac... Crap... (although it's a great improvement and tells me i was right in my diagnostic

Well, then i removed half of the RAM and booted it again.

I got this!

That is cool!

When i push the reset button i get this:

Which points to:

ID=13 Uninstalled InterruptThe Macintosh uses an interrupt to identify when devices like keyboards and disk drives need service. Routines must be available in memory to tell the computer how to service the device. If those routines aren't available, you see this error.

Which i don't understand but it probably has something to do with the ROM or the PRAM. But since i don't have a ADB keyboard, i can't zap the PRAM, can I?

Already this repair is turning out great! Done so far:

• replaced adress-muxes in video circuit and the 74LS166 (that turns parallel video data into a serial bitstream)
  
• replaced Video-ram
  
• removed half the RAM
  
• repaired 1 via/trace to an adress-mux

 

[uniserver]

so when you said that your removed half of the ram,

you left bank A pouplated… and removed the ram simms from bank b?

When you got the question mark, did you try to boot from a floppy or the scsi?

are you sure you tapped the reset button and not the interrupt button?

if you want to reset it just flip it off and then on again from the back… at this stage of your diagnostics.

no reason to induce more variables...

 

[Sebastian]

A is populated, B is empty

Question mark after i pushed a button, i checked and it was the interrupt button indeed, good call. When i reset after the sad-mac, i still get the sad mac.

Trying to boot from SCSI hdd, no floppy here.

 

[Sebastian]

Well, an interesting night to be sure!

I confirmed that the second batch of RAM was bad, because it caused a Simasi-mac installed alone or with the other RAM:

Without it i got the question-mark

After pulling out the HDD, i noticed it wasn't spinning up, so i opened it and helped it a bit

But even with it spinning, it still wouldn't boot. So i closed the drive and gave it a whack or two... and suddenly!

and then!

I'm not sure how trustworthy the drive is, but hey! It works! All it took was a few chips and some elbow-grease!