Intermittent boot failures - NeXTStation Mono Turbo

Started by dylanmcnamee, October 30, 2019, 09:17:30 pm

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dylanmcnamee

October 30, 2019, 09:17:30 pm Last Edit: October 30, 2019, 11:17:12 pm by dylanmcnamee Reason: changed subject
Wouldn't you know it, but after about 30 reboots, and getting everything "just so", I unplugged my NeXTStation, and installed it in its permanent home, and the very next power-up failed, just after the booting from... message. Here's the screen it becomes unresponsive (even to the power button):
This isn't too different from the behavior of my Mac SE/20, which I also have a hunch needs a bunch of new capacitors. Has anyone else seen this, and was a recap-job what fixed it (fingers crossed?)

thanks,
dylan
(EDIT changed the subject - it's failing at different points of the boot process, doesn't seem capacitor related)

barcher174

At this point a recap should be the starting point for any hardware fault troubleshooting. This is a new one for me. My first guess is its either memory corruption (Caps are a likely suspect), or a bad CPU.

dylanmcnamee

Fortunately, I decided to try reflashing a new microSD card to see if that was possibly the cause, and indeed it was! Somehow an unclean-reboot caused my kernel to get corrupted. Hmmm. Anyway, it wasn't the capacitors after all (this time...I'll get a kit ready for when they do go). Thanks!

dylanmcnamee

October 31, 2019, 01:30:09 am #3 Last Edit: October 31, 2019, 05:11:46 am by dylanmcnamee
I'm in a situation where, with a freshly flashed SD (known good image) boots to various degrees, sometimes all the way up to a login window, which succeeds. Then a reboot or two later, I get a panic, dropped to a monitor window, but not really sure what I can do to diagnose it from there. Maybe it's still bad capacitors, but to narrow things down, I thought I'd test the memory before using a soldering iron on this gorgeous machine.

I found the Diagnostics disk in http://www.nextcomputers.org/NeXTfiles/Software/Diagnostic_Utilities/ (the file called 68040.tar.gz) Seeing that it's a file, not a disk image, I copied it to a DOS-formatted floppy, hoping that it doesn't need to be on a NeXT formatted floppy, since it's not easy to make one without a working NeXTStation, which is what I'm trying to do. Booting with Cmd-` got me to the ROM monitor, but
bfd dvt040
didn't work - it complained about "Bad Label" as it read the floppy, so I'm guessing it does need to be a NeXT formatted floppy.

Next step was to fire up an OpenStep VM and create a NeXT formatted floppy image with that file. I created a new unformatted Floppy.img in VirtualBox and launched my VM. It prompted me to format the disk, so I chose NeXT format, then copied dvt040 to the floppy, ejected it, then did a "dd if=Floppy.img of=/dev/disk8" (disk8 is my USB floppy drive on macOS). This seemed closer, but still no joy:

> bfd dvt040  // <- spins up floppy drive, response:
bad version 0xb80000fa
bad cksum
bad cksum
bad cksum
bad label


Giving up on dvt040, I remembered there is a memory test in the Boot ROM, which I enabled, and after the longer power-on self test, the DRAM seems to check out, though I doubt it was a thorough test. Maybe it is time for a recap after all?

Any advice about what I can/should try to narrow the cause would be welcome.

Rob Blessin Black Hole

Hello Dylan: If you can login to the NeXTstation and insert a floppy disk , you should be able to easily format it in NeXT file format with a panel that pops up and hope the system stays good through a few minutes of formatting.
Rob Blessin President computerpowwow ebay  sales@blackholeinc.com http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93

dylanmcnamee

Quote from: Rob Blessin Black Hole on November 03, 2019, 10:37:35 pmHello Dylan: If you can login to the NeXTstation and insert a floppy disk , you should be able to easily format it in NeXT file format with a panel that pops up and hope the system stays good through a few minutes of formatting.
It no longer stays up long enough to do that, which (I think) is further indication that a recap is my next step.