A couple of Cube-specific questions

Started by Huxley, June 05, 2023, 06:00:13 PM

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Huxley

Hi all! I've got a couple Cube-related questions, would love some advice or guidance on either/both:

1. My Cube (technically a NeXT Computer upgraded with a 25MHz '040 Cube motherboard) has both the original 760MB SCSI hard drive and the MO drive installed. Both work well thanks to the excellent restoration work by Brian Archer (who sold me my NeXT's), but my "day to day" preference is to use a SCSI2SD I purchased from Rob Blessin. Here's the question: what's the best way to mount the SCSI2SD inside the Cube? Setting aside the option of installing it into an external case (something I'm open to, if there's a good recommendation), I'd like to install it inside the Cube. I currently have it in there just kinda sitting between the back of the HDD + MO drives and the fan (the SCSI2SD is wrapped in plastic to avoid shorts), but it's kinda loose and I don't like the thought of it flopping around inside. Any suggestions on a more stable / permanent mounting solution would be appreciated!

2. When I bought my Cube from Brian, he included a little circuit board with a tiny incandescent light, which can be installed into the Cube to simulate the power-draw requirements from the CRT, should I opt to use the Cube with an LCD monitor instead. It's been a few years now and I can't remember: is there any downside to installing that board and using the Cube interchangeably with a CRT or LCD panel, or should the board ONLY go in there if I'm definitely going to be using an LCD? @barcher174 - I hope I haven't mangled that summary of your clever board too much!

Oh, and one more bonus question: my NeXT MegaPixel monitor (greyscale) is afflicted with the faint-image issue that seems pretty common at this point. Has there ever been a reliable solution to this issue? I've poked around here and on Facebook found a few threads on the topic, but it seems unclear to me if it's an issue with the phosphors on the tube fading out, or if it's an issue with the electronics in the display. I'd love to know if there's a real solution, or if we're all doomed to watching these beautiful displays fading away...

Thanks for any info you guys can share!

Huxley

barcher174

Hi Huxley

1) I think there is a 5.25" 3D printable bracket floating around somewhere. I've seen others use velcro to attach in the case.

2) You should only install the card when using an LCD. Remove for CRT. You could also install the bulb on the NU_IO 3 pin header when using the cube.

3) I have had limited success using a tube rejuvenator. I -think- the monitor I sold you may have already been recapped.

nuss

Re: Megapixel Monitor: I remember that in the 90s it was discussed that some gas is fading out of the tube over time. Is your issue with brightness or with contrast?
DON'T PANIC

paolo.bertolo

About the CRT dimming: I have a N4000 (plain) monitor, it's all in all in more than acceptable conditions. Surely not as good as the other N4000A I have, but still OK.
What I have noticed is that the monitor behaves somehow erratically. Most of the times, soon after start up is very dim and it takes time to warm up (?).
Occasionally, though, it starts immediately very bright.
Reproducible patterns:
1) the longer I use it, the brighter it gets
2) if the screen saver kicks in, it gets much brighter even if there's nothing beamed
I once forgot the unit on for the whole night (totally dark screen saver on). The next morning the display was impossibly bright, definitely too much to the point I thought it got permanently damaged. After switching it off and on again after a short while, everything was as usual.
So, my guess it that there's something drifting over time, but what exactly I have no clue.

barcher174

Hi Paolo,

That actually sounds like a capacitor issue to me. Variations in behavior with heat are a typical sign.


paolo.bertolo

#5
Hi Brian,

Thanks for the hint, I have the same thinking.
A few years ago I recapped the soundboard, but I must admit I don't remember if I tackled the high voltage board, too.
I need to check, but probably not.

(Update: just checked my cap list, I only did the soundboard. So it could indeed be that there's one or more of those fatty caps in the analog board drifting over time. Will see what I can do at the first occasion).


rbz

Quote from: Huxley on June 05, 2023, 06:00:13 PM1. My Cube (technically a NeXT Computer upgraded with a 25MHz '040 Cube motherboard) has both the original 760MB SCSI hard drive and the MO drive installed. Both work well thanks to the excellent restoration work by Brian Archer (who sold me my NeXT's), but my "day to day" preference is to use a SCSI2SD I purchased from Rob Blessin. Here's the question: what's the best way to mount the SCSI2SD inside the Cube? Setting aside the option of installing it into an external case (something I'm open to, if there's a good recommendation), I'd like to install it inside the Cube. I currently have it in there just kinda sitting between the back of the HDD + MO drives and the fan (the SCSI2SD is wrapped in plastic to avoid shorts), but it's kinda loose and I don't like the thought of it flopping around inside. Any suggestions on a more stable / permanent mounting solution would be appreciated!

If you are still looking for a way to mount the SCSI2SD (or ZuluSCSI) in your cube I designed a 3D Printed 5.25" adapter which is available on Thingiverse and its what I use in my cube. Thread with links / pictures is here: 3D Printed 3.5" and 5.25" SCSI2SD Mounts (Generic)
Turbo Slab - N4000A, nonADB, SCSI2SD 5.1, 32m
Turbo Color Slab - VGA, ADB, NU_IO, SCSI2SD 5.1, 128m
Cube - 030 16m, 2x SGI Octane, Sun SPARCclassic

Huxley

Quote from: rbz on June 15, 2023, 11:49:34 AMIf you are still looking for a way to mount the SCSI2SD (or ZuluSCSI) in your cube I designed a 3D Printed 5.25" adapter which is available on Thingiverse and its what I use in my cube. Thread with links / pictures is here: 3D Printed 3.5" and 5.25" SCSI2SD Mounts (Generic)

Awesome, I'll look into that!

Okay, now I'm here with a new / weirder Cube-specific question:

Two or three times recently, my Cube (with the 68040 @ 25MHz) has gone totally comatose. Specifically, it will boot up and run just like normal (currently booting from a SCSI2SD) with the NeXT MegaPixel monitor connected. However, if I shut the machine down and then attempt to power it up again, I get... nothing. No fan, no monitor activity, literally nothing - as if it suddenly wasn't even connected to power. Given that it was running just fine 10 seconds prior, this seems pretty weird.

Any idea what's causing this? It happened once immediately after I installed the SCSI2SD so I went through and re-seated everything, and then it booted up just fine so I thought maybe I'd fixed it via some light tinkering. However, now it's a week later and it just happened again - my Cube was running fine for a couple hours, I shut it down, and 2-3 minutes later when I went to boot it up again, it's doing a very accurate impersonation of a tree stump. Zero signs of life at all right now.

QUICK EDIT: Would this behavior (booting sometimes, other times playing dead) be consistent with a motherboard battery that's dying-but-not-entirely-dead?

Thanks in advance for any tips!

Huxley

barcher174

Yes, I would suggest trying a new battery.

nuss

Quote from: barcher174 on June 16, 2023, 01:24:28 AMYes, I would suggest trying a new battery.

I would like to second this suggestion. Had the same behaviour with a dying battery.
DON'T PANIC

Huxley

Quote from: barcher174 on June 16, 2023, 01:24:28 AMYes, I would suggest trying a new battery.
Quote from: nuss on June 16, 2023, 01:58:23 AMI would like to second this suggestion. Had the same behaviour with a dying battery.

Awesome, thanks guys! I've got a pack of replacement batteries on order now, should have them in hand in a few days. Whew - fingers crossed that this will cure my narcoleptic Cube!

 ;D

Huxley

dramirez

Restoring a NeXT Cube with a Dimension board.

Huxley

Quote from: dramirez on July 06, 2023, 01:24:26 PMdid the new battery help?

Sorry - I forgot to follow up! Short answer: yes, the new battery seems to have made my Cube much more reliable, especially with the weird refusing-to-power-up issue. The Cube was a star attraction at our exhibition with Golden Gate University in early June, so ensuring that it would boot was a real last-minute stress for me. Thankfully, it fired right up and ran like a champ all afternoon.

Thanks for the helpful guidance, everyone!

nuss

Good that it worked out and I am glad to hear, that your cube was an attraction on the exhibition :)
DON'T PANIC