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Step by Step - reviving a NeXTstation Color - after 20 years

 
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dglcinc



Joined: 01 Oct 2016
Posts: 6

PostPosted: Sat Oct 01, 2016 5:15 pm    Post subject: Step by Step - reviving a NeXTstation Color - after 20 years Reply with quote

Hi all:

I used to be a NeXT developer. In 1995 I crated up my NeXTstation in the old roadie cases (deep foam) that were making the rounds back then, and just yesterday cracked them open. Initially it worked (!), but then it stopped, I'm looking for advice/help to troubleshoot. I'll detail everything with pics and hopefully someone has some ideas.

The 21" triniton doorstop is long gone (still have the giant roadie case!). I have the slab, sound box, printer, and all the cables. I hooked it up to a (vintage Smile) Samsung 760V-TFT using the Sun/NeXT VGA conversion cable (part number 530-2917-01-13W3 for those who also need to do this.)

Steps I took:
1. took all the stuff out. (oh, that's where I put that Xycel modem!)
2. breathed sigh of relief, did not pack up the printer with the toner cartridge inside!
3. took the cover off the slab and inspected it. Connectors on back and electronics on board look good (to me, no expert.) Some corrosion on the magnesium bits and on the heatsink on the bottom.
4. Used Deoxit D5 (and Deoxit D100 in a few places) without going too crazy to clean the corroded magnesium and the mobo. Used a compressor to blow dry etc.
5. diassembled and cleaned the mouse. The metal wheels were corroded but salvagable. The rubber coated ball, after a spritz with some vinylex, is literally like new - amazing.
6. hooked it all up, using aforementioned vga converter cable to hook up the soundbox to the flat panel.
7. crossed fingers.
8. hit the power button.
9. OMG! It worked! Immediately went to the boot animations; first "booting from disk...", then "checking disk..." (re-crossed fingers and also toes), and after about ten minutes, LOGIN SCREEN. I was amazed.
10. Oh, !%#^. What was my account name and password? What was the root password? Tried a couple things, then booted to ROM monitor.
11. typed "b sd -s" (of course it should have been "bsd -s"). The moment I hit return, it made a clicking noise (not pop/burning noise, just "why did you type that command you bozo I'm shutting down" noise.)
12. Now, no response. When I press the power button on the keyboard every so often I will hear a very slight pop from the soundbox speaker but otherwise nothing.
13. After all this happened (OK I missed this the first time around, I should have done this before booting) I replaced the BIOS battery, the freaky BR-2/3A 3V battery which amazingly is readily available on Amazon (thank you Prime.)
14. Still no love. No signs of life. Checked all connections, tried unplugging overnight, etc. No obvious leaky caps on the mobo, but I'm not an expert (see photos if you are, maybe you'll see something.)
15. The next thing it seems to me is the power supply, which I will get if needed.

Couple questions for the group so I can get to next steps (no pun intended):
a. Is there a "paper clip" test for a NeXT power supply, like for a PC, so I can verify that it is good or bad?
b. Let's assume for a minute the PS is good - what are some other common causes of abrupt power off followed by no signs of life.

Thanks all to the group and to Rob Blessin for the welcome back, and shout out to anyone else I in the group I knew from back in the day.

David Lewis

Serial number:

Mobo shots:












Picture of cable used to connect a VGA flat panel:
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barcher174



Joined: 07 Dec 2012
Posts: 535

PostPosted: Sat Oct 01, 2016 5:30 pm    Post subject: Reply with quote

It does sound like a power supply problem to me. Luckily Rob is still around and has them cheap (I think ~$20). There is no paperclip test for them, but you can still bench test them with a little effort. You need to supply 3V to power on. You should be able to use the pinout here: https://heller.userweb.mwn.de/NeXT/power_supply_subst.html
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dglcinc



Joined: 01 Oct 2016
Posts: 6

PostPosted: Sat Oct 01, 2016 6:05 pm    Post subject: Reply with quote

OK thanks. Teeing up a power supply. Is there any documented procedure to bench-test the PS? Rob pointed me to the technical manuals but I don't see a PS test procedure there.
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dglcinc



Joined: 01 Oct 2016
Posts: 6

PostPosted: Sat Oct 01, 2016 6:10 pm    Post subject: Reply with quote

In the link you supplied, on the pinout, if I read that right, if I supply +3V (e.g by hooking the battery + to the 3V pin and - to one of the grounds) if the PS is working it should power on and show nominal voltages on the pins?
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dglcinc



Joined: 01 Oct 2016
Posts: 6

PostPosted: Sat Oct 01, 2016 6:28 pm    Post subject: Reply with quote

OK did not hook up the 3V on the power pin but I did pull out the power supply connector on the motherboard and tested the 3V pin on the mobo across the ground. I saw a strong 3V signal (about a second) on the 3V pin, so I would agree it looks like the PS is bad. Thanks!
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dglcinc



Joined: 01 Oct 2016
Posts: 6

PostPosted: Wed Oct 05, 2016 6:55 pm    Post subject: Arggh. Power supply did not work. Reply with quote

OK I got a NOS power supply from black hole but that has exactly the same behavior as my old one - a very slight popping sound on the sound box but otherwise no signs of life. The thing that puzzles me is that the computer was running pretty well and shut down without any particularly fizzly noises right after I hit return on the erroneous rom monitor command (b sd -s vs. the correct bsd -s.) It was almost as if I typed the command "shut down and don't come back. Ever." So the problem is one of two things:
1. the command I typed horked the rom in some way so that the machine won't power on (smarter people than me probably think that's silly)
2. Some ancient component on the mobo decided to go to heaven at exactly that moment.

Anyone have ideas on which of these two things it might be and how to proceed next? Is there any way to "reset" the rom/bios like on a PC?

If the answer is truly 2, it's pretty much beyond me to do deep electronics diagnosis or get into serious geekdom like recapping the mobo (assuming that could be part of the problem.) There are no obviously leaking or swelled caps, assuming they actually show their faces when misbehaving.

Suggestions anyone, shy of putting it back in the crate for another 20 years?
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barcher174



Joined: 07 Dec 2012
Posts: 535

PostPosted: Wed Oct 05, 2016 9:23 pm    Post subject: Reply with quote

Ok it gets a little more difficult from here. The firmware is stored by the battery so if you pull the battery and leave it for 15min that should clear anything, but I doubt that's your problem. Capacitors are usually the first step when I troubleshoot a logic board. Then I would take readings from the RTC (the chip next to the battery). Next check that the poweron signal is going to the ICP (the big grey next chip in the middle). Depending on how you value the time/money you might decide to replace the logic board.
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dglcinc



Joined: 01 Oct 2016
Posts: 6

PostPosted: Sat Oct 15, 2016 3:24 pm    Post subject: Problem Solved! Reply with quote

OK, I went all medieval on this thing and ordered replacement logic board, keyboard, floppy drive, and hard drive from black hole. It was going to run dammit!

I replaced the logic board first, nothing. still dead.

I replaced the keyboard, nothing, still dead.

I replaced the hard drive. Success! That was it!

So, for those who have a dead machine, you can add this to the list of things to check. The replacement hard drive is the pre-loaded SD card drive that black hole sells, so no more messing around with spinning disks.

Wow, it's slower and more primitive than I remember it...
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barcher174



Joined: 07 Dec 2012
Posts: 535

PostPosted: Sat Oct 15, 2016 4:44 pm    Post subject: Reply with quote

Wow. Would not have suspected the hard drive to cause the machine to do this. Must have been a short on the power rail.
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Rob Blessin Black Hole
Site Admin


Joined: 05 Sep 2006
Posts: 521
Location: Ft. Collins, Colorado

PostPosted: Sat Oct 15, 2016 11:55 pm    Post subject: Reply with quote

Yeah you are back up and running , well at least you have spare parts almost enough to have a second box , so with your original motherboard and the new scsi sd it just works now?

As the majority of the time it is either a bios battery or power supply, bad power cord , then blown caps or other components on the motherboard or doa keyboard .... having a doa drive as the root cause ,
usually you would hear a click at least or disconnecting the drive it would still spin the cooling fan but it must have been a short
as I've worked on a lot of hardware .it is a new one, so I'll add doa drive short disconnect it completely to the troubleshoot checklist .



Smile Best Regards Rob
_________________
Rob Blessin President computerpowwow ebay sales@blackholeinc.com http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community since 2/9/93
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pentium



Joined: 23 Jun 2006
Posts: 1137
Location: Kamloops, BC

PostPosted: Thu Oct 20, 2016 7:43 pm    Post subject: Reply with quote

Could I ask one tiny favor of the OP, please?
Scale your images. For most people a 3,264px 2,448px image stretches the hell out of the page as the average person has a resolution around 1920x1080.
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-NeXT 68040 Cube with NS 3.3 and 64Mb ram
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