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NeXT Cube boot troubles

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Joined: 13 Mar 2013
Posts: 12

PostPosted: Thu Mar 08, 2018 6:17 pm    Post subject: NeXT Cube boot troubles Reply with quote

Hi folks,

It's been a very long time since I've had my hands on some NeXT hardware. I just don't come across it much in my searching.
Until now! I snagged a turbo cube with a NeXTDimension board, and I'm excited to get it up and running. I'm halfway there:
-It turns on fine, but will most likely display a blank grey screen
-Sometimes it'll go to the self-test, which passes, then attempts disk boot, and then network boot (where it hangs).

I'm not sure if this is a hardware problem, or if the primary display output is to the NeXTDimension card. I'd like to check before I go about yanking parts around.

I don't hear the hard drive running / seeking, so I imagine it's toast. I wouldn't be surprised. The plastic mounting rings between the disk assembly and the chassis had shattered, so I'd imagine it got bumped around a bit during shipping, if it wasn't already toast. The seller had very little to say about this one, since it came as the machine only.

Any tips are greatly appreciated!
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Rob Blessin Black Hole
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Joined: 05 Sep 2006
Posts: 710
Location: Ft. Collins, Colorado

PostPosted: Fri Mar 09, 2018 12:15 pm    Post subject: Reply with quote

Hello: Well here is what I do ...... every NeXT hardware Cube or Slab has it's own unique history. Some well cared for and others have been through hell in storage literally like an attic by the ocean for 20 years.

So signs on the out side and inside are obvious , cosmetically is it clean or banged up.

Before doing anything always , I mean always do this before starting up your new NeXT , trust me it is happy it has landed with you ! So the best thing you can do before applying power is visually inspect it internally by opening them up.

For slabs a single screw in the back of the Case and it hinges forward , I've seen many of them pried open because they could not find the screw . Steve Job's requirement was a single screw for slab case's from a former NeXT employee as he was tired of cases with 18 to 20 screws.

On Cubes you will need an allen wrench or cube tool , 3 MM ,
unscrew 4 screws in the back . Slightly open the case and unplug the fan .

The Cube will benefit from a thorough cleaning out. Lets start with that fan , it is held in place by 2 screws, on older ones 4 screws same size screws as back plate screws.

The grate covering the fan can also be carefully removed , coxing it gently close to the corners until it frees up at the tabs.
Be careful the tabs holding it in place are very brittle with age but with any luck you pry it free, you may have to glue a tab pack together . The goal here is clean out all the dust bunnies in the cube and on fan blades .
, if you want painstaking detail on disassembly , I scanned and uploaded the original NeXT service manuals !

So yes lets proceed to now remove the dimension board , if you have one a firm tug she slides right out

and NeXT the motherboard , a firm tug about an inch or so then stop, proceed to unplug the cables from the board and drives and clean them as well. and carefully slide the motherboard the rest of the way out .

NeXT had such a tight clearance tolerance ; if the board has a socketed CPU not surface mount CPU that the splines on the heat sink on the processor can actually catch on the inside of the drive harness , you can also remover the drive harness first. Take care whilst sliding the motherboard out , if you feel resistance it is probably ram or splines catching the powersupply/drive harness. So if this happens you might as well remove the Drive harness first.

next is the power supply and harness , 2 screws at the base , sometimes these are missing but everything slides out with a firm tug , nicely engineered .

No you should be looking at an almost empty case , might as well take the tear down, the rest of the way , carefully remove the drive rails , these have 2 tabs that hold them in place in the front, they can be carefully coxed to pop up then out both bottom and top rails. they to are brittle plastic and 30 years old , patience on all this is worth it.

the back plains is NeXT 3 screws or on really old Backplainss 10 tiny screws hold it in place and last the dust screen at the bottom .

Complete disassembly achieved, I recommend a can of dust off and armor all and a roll paper towels, I've seen it all at this point cacoons, leaves, screws, spiders (careful I had a bite from a bloody Brown Recluse working on one Cube, had to be as we don't have them here normally lol), yes I've found money and live bugs , roaches lol remove all the crap and shine it up, no gold bars yet.

So I recommend replacing the capacitors on the motherboards , we offer cap kits for do it your selfers $10 or Mat my Caps guy does a professional excellent job on new caps for $65 per board includes caps and add shipping or Charles over at does an excellent job as well. If you send them here we can check them to make sure everything works before and after capping . Some boards have additional problems and also we have have the NeXT diagnostic tools here , you have to set this up in parameters after testing system, loading from disk , command ~ at NeXT> p for parameters ,
boot en? is the default, if you have removed or replaced the battery change this back to sd , scsi device
after diagnostic tools are installed then you can choose boot extended diagnostics= Yes , don't do this with out the tools installed or she hangs....

and or further errors guys like Brian , that are magicians at troubleshooting and repairs and if they have time may have a solution for a fee. (Brian hope I'm not overstepping here)
New caps are a must at this point for the boards as they are all leaking after 30 years and will cause further damage and wreck havoc exactly as you describe . The electrolytic ones are now replaced by ceramic.

The power supplies seem to be OK but I suspect eventually they to will need new caps.

The hard drives are also most likely toast as well , a great replacement is the code src microscsi2sd , I like the version 5 cards limited success with version 6 as they seem more tempermental.

I offer a great solution and have sold hundreds , I have 4gb version user , developer , y2k patches for $139.95 or 8Gb extreme pro loaded with hundreds of apps for $199.95 , if you are a do it yourselfer the sd runs about $70 inertial computing has them on eBay and then add an extreme pro card $20 , then you need NeXTstep, I have new downloads or originals for sale or some sites may have sketchy downloads potential phishing crap and hella time to overcome the learning curve on the configuration files, installs etc and searching through threads on a quest for fire .... no worries just contact me and I will have mercy on your tortured soul lol and provide you with a working config. I don't make a lot of money at this but it is heart and pays the bills been at it for 25 years.

Optical drives these are mostly toast but there is now success of refurbishing them , for a price it can be done but results are not always guaranteed. So for a holy grail as 95% are DOA working refurbished optical drive at $500 as it is very labor intensive some times take parts from several but cool to have working. Also any parts please keep those or donate them to us as we pay forward and help the community....

We also offer internal new old stock floppy and cdrom solutions that work well internally in cubes . Again reasonably priced heck a NeXT logo power cord was over $50 on eBay recently a poster sold for $365 yikes.

So I'm on eBay as computerpowwow and have site to eBay is efficient, don't see it listed ask and and we can also make direct deals through here , I'm flexible , payment through paypal. I ship globally.

So once everything is clean and recapped both motherboard and dimension , my recommendation , the old drive ditched new sd in place and reassembled , I will bet you will have working NeXT hardware.

Other thing is ram flaky ram to can cause errors,
I have ram tester and have brand new ram or tested working used ram , yes newly manufactured 30 pin for $2 a mb or used for $1 a Mb for 72 pin and or 30 pin ram.

Cubes 64Mb max 16 *4 mb 30 pin , Turbo Cube 128Mb max 4 *72 pin FPM simms , dimension 64Mb max 8 * 8Mb FPM simms

Also power cord may have issues , I think covers what I usually do and reassemble , good stuff a working NeXT, hope that helps !

Bios Battery if it doesn't power up try this first, batteries plus $8 or we have them as well panasonic 2/3 volt , please note changing the battery changes default boot to ethernet see above for parameters to change back...

Apologies if it is choppy , I'll go back through and edit it to clean up errors , rough draft to get it out here and by all means feel free to add your observations as well. The natives are friendly.

Also hundreds of examples of NeXT stuff , hard ware I've done for customers, tips, etc... on my channel

Best regards Rob Blessin
Rob Blessin President computerpowwow ebay
303-741-9998 Serving the NeXT Community since 2/9/93
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Joined: 13 Mar 2013
Posts: 12

PostPosted: Sat Mar 10, 2018 1:32 pm    Post subject: Reply with quote

Quite the reply, but I'm familiar enough with the Cubes to have already cleaned it out completely. With the NeXTDimension card removed it boots fully. I've gone into the settings and disabled the monitor output on the card for the time being and I'll test it again with the card in place.
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Joined: 24 Feb 2018
Posts: 7
Location: Toronto

PostPosted: Sun Mar 11, 2018 7:00 pm    Post subject: Reply with quote

Wow that is quite the reply, lots of great information in there. Thanks for posting. A very good read, and I don't even have a cube...

Cheers. :0)
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