VOGONS


First post, by King_Corduroy

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Hi guys! I was wondering if anyone has any suggestions where I might either be able to send this teensy PSU off to be fixed or maybe where I can get something that might replace it nicely. It's in a Cybernet computer and without the computer part plugged in I plug in the PSU and the power adapter pack starts giving me warning beeps like it's having a fault. I figure there's probably something newer I could slap in there and adapt to the odd single cable AT style connector or maybe send it off to someone who knows a bit more about trouble shooting things like this, cause other than swapping capacitors I don't even really know where to begin. 🤣

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Reply 1 of 15, by cyclone3d

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Micro ATX PSU and ATX to AT adapter.

But that depends on the voltages on the PSU in that thing.

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Reply 3 of 15, by cyclone3d

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The power draw isn't the problem at all, what voltages being supplies by the stock PSU is what needs to be verified.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 4 of 15, by King_Corduroy

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Impossible to verify with the PSU not working and the computer basically does not exist.

Check me out at Transcendental Airwaves on Youtube! Also wtf, why are whoppers so good?!

Reply 5 of 15, by cyclone3d

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King_Corduroy wrote on 2021-05-19, 04:59:

Impossible to verify with the PSU not working and the computer basically does not exist.

Does the PSU circuit board not list the voltages?

You may also try contacting Cybernet. I don't see anything quite that old listed in their downloads but they may still have info kicking around if you are lucky:
https://www.cybernetman.com/

What model do you have?

Is it the same as this one? They had to replace a transistor in the PSU to get it working:
viewtopic.php?f=46&t=51841

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 6 of 15, by JidaiGeki

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This guy has one which needs a 12V power pack, and his thread has some info on alternative power as well:

KNS - Keyboard Network Station 486 PC

I’ve got one without PSU so have been looking for external power packs, or a power solution straight to the main board.

Reply 8 of 15, by weedeewee

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if the colors still mean anything then the little adapter inside the computer delivers 5v, -5v, -12v, 12v. (red, white, blue, yellow)

Wouldn't be surprised if changing the caps fixes it.

What voltages do you measure ?

Right to repair is fundamental. You own it, you're allowed to fix it.
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Reply 9 of 15, by King_Corduroy

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To answer the questions: Yes I think mine is slightly newer than his but same case and power plug, probably the same PSU. I found that all Cybernet computer use the same four pin plug so it should work with any of them as long as they are positive on the top two pins (I think, I'm not sure cause mine it's working but the Elite series use the same power adapter as the newer ones so I'm guessing the old ones should be the same as well. The exception being the D5 machines). I'll get some pics of mine in greater detail when I come home (after 11pm central time) but mine has an AMD X5-133 ADZ for a CPU. I think that makes it socket 5 or 4? I'm not sure, it looks as though it might be soldered in though.

Also I can't measure any voltages off the PSU, it's acting like it's shorted out I think because the Power adapter begins to beep in protest which is generally not good.

Check me out at Transcendental Airwaves on Youtube! Also wtf, why are whoppers so good?!

Reply 10 of 15, by cyclone3d

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Ok, so it is a Socket 3 CPU. AMD 5x86-133. Probably is soldered in.

The archived pages actually mention an AMD 5x86 model - Zero-Footprint-PC: 5x86 Model(KPS1001)
http://web.archive.org/web/19990220043926/htt … n.com/index.htm
(NIC driver in bottom left hand corner but the download doesn't work)

http://web.archive.org/web/19990222064412/htt … com/cybnet4.htm
http://web.archive.org/web/19990222075746/htt … com/cybnet5.htm

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 11 of 15, by kdr

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King_Corduroy wrote on 2021-05-19, 16:33:

Also I can't measure any voltages off the PSU, it's acting like it's shorted out I think because the Power adapter begins to beep in protest which is generally not good.

Your PSU is almost certainly supplying the standard +12V/+5V/-5V/-12V rails. The motherboard has an ISA slot, and each of those rails should be connected directly to one (or more) pins of the ISA bus. Looking at the ISA bus pinout shows that pins B3, B5, B7, and B9 are the +5V, -5V, -12V, and +12V rails respectively. Pin B3 for instance is the third pin from the front and the Bxx side of the ISA connector is the side "underneath" the card.

Grab a multimeter, put it in continuity test mode, and verify that the PSU wiring colours match the "standard" (they almost certainly will). Then check the resistance between each of the rails and ground -- it could be that one of the rails is shorted.

If all the voltage rails look good, then all you need to do is find a DC-DC power supply (which should easily fit inside that case) with AT or ATX style voltages and wire up a connector. If you go for an ATX supply without -5V the standard caveats apply: some ISA cards need the -5V, most cards do not, and that motherboard probably won't need it either.

Reply 12 of 15, by pentiumspeed

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This is exactly how I did same way with my compaq computers with non-standard pinout, I took a print out of ISA 16 bit slot and measured to get the pinouts except one which is power good signal which is a easy to try with piece of 100ohm resistor to a power good signal from a test PSU and try one unknown pin or another till PC powers on.

Cheers,

Great Northern aka Canada.

Reply 13 of 15, by BitWrangler

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I just remembered this sort of thing exists...
https://www.mini-box.com/M3-ATX-DC-DC-ATX-Aut … PC-Power-Supply
If you wanna spend Money with the capital M there...

But you might troll eBay for a while and pick up something similar used and cheap.

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Reply 14 of 15, by cyclone3d

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They are $28 new on Amazon. Just search for pico ATX.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 15 of 15, by Cyberdyne

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Moore than sure that Black is Ground, Red is +5V, Yellow is+12V, Blue is -12V and White is -5v. Usually those mini motherboards start to work only with +5v and +12v. Few of them even start to work with only +5V.

I am aroused about any X86 motherboard that has full functional ISA slot. I think i have problem. Not really into that original (Turbo) XT,286,386 and CGA/EGA stuff. So just a DOS nut.