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How to power on a 486 computer without the case and power button?

A

amino glycine

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Joined
Aug 11, 2016
Messages
10
Location
Fairfax, VA
Hey all,

Sorry if this question has been asked before, I did some searching and couldn't find a clear answer.

I'm in the middle of putting together a 486 machine for fun but old AT cases are hard to come by and expensive online, probably due to shipping costs. Is there a way, once I hook up the power supply to the motherboard, to power on the computer without a case's power button? I'll get a case eventually but I'd like to be able to test my set up before doing that.

Thanks!
 
Yes. Could you describe exactly which power supply you are using? A wire can connect the two necessary pins and duplicate the effects of a switch. Use the wrong pins; boom goes the power supply.

If you intend on keeping it like that for several boots, I think soldering in a temporary switch is a good idea.
 
What kind of power supply do you have? And what connector does the board use? (AT or ATX?)

Most 486 era AT power supplies have a connector for a 120 volt switch. If you attach a similar 120 volt switch, then yes you can power it on.

ATX power supplies with an AT converter will, I think, have a switch on the converter to emulate an ATX softswitch.

Earlier AT power supplies will have a paddle switch built on to the side, and can be switched on with no additional futzing.

Note that power supplies can come in many shapes and sizes so if you are purchasing one today, it may not necessarily fit in a case you find later. (But one would hope the case would already have a good power supply)
 
amino glycine said:
Hey all,

Sorry if this question has been asked before, I did some searching and couldn't find a clear answer.

I'm in the middle of putting together a 486 machine for fun but old AT cases are hard to come by and expensive online, probably due to shipping costs. Is there a way, once I hook up the power supply to the motherboard, to power on the computer without a case's power button? I'll get a case eventually but I'd like to be able to test my set up before doing that.

Thanks!
Click to expand...

1. If you put your location in your profile we could see where you are , and some one near may have a case they would donate to the cause.

2. If memory server me correctly, it is just a low voltage connection that goes to two pins on the mother board. The switch links the pins, so you can just use a normal Mother Board jumper to turn the thing on and off. Of course this is fiddly so if you can find a connector with wires then solder a switch across them, or even just twist them together and in-twist....
 
g4ugm said:
2. If memory server me correctly, it is just a low voltage connection that goes to two pins on the mother board. The switch links the pins, so you can just use a normal Mother Board jumper to turn the thing on and off. Of course this is fiddly so if you can find a connector with wires then solder a switch across them, or even just twist them together and in-twist....
Click to expand...

Be careful with that, you're probably thinking about ATX. 486 is AT and the wires from the switch go directly inside the PSU, not just some jumper on the motherboard that you can short-circuit to make it start. There is live current on these wires.
 
konc said:
Be careful with that, you're probably thinking about ATX. 486 is AT and the wires from the switch go directly inside the PSU, not just some jumper on the motherboard that you can short-circuit to make it start. There is live current on these wires.
Click to expand...

In that case the switch should be part of the PSU, non-removable and fully insulated.
 
g4ugm said:
In that case the switch should be part of the PSU, non-removable and fully insulated.
Click to expand...

Not necessarily, in many cases (especially the "generic" ones) the switch is part of the case and the PSU connects via wires to it. Insulated wires, but still needs caution.
This is a very common case for example:
2psfig5large.jpg
 
I don't believe that would pass UK Safety legislation for a PC with user removable covers, which is probably why I have never seen one like that. In the UK these usually have a large "boot" over the back of the plug, but I see on Ebay USA there PSU's with similar spade terminals for sale...

http://www.ebay.com/itm/172001233006

in which case they can have a suitable switch added ...

http://www.ebay.com/itm/141676367388

but of course as you say it needs some insulation to prevent accidental shocks...
 
krebizfan said:
Yes. Could you describe exactly which power supply you are using? A wire can connect the two necessary pins and duplicate the effects of a switch. Use the wrong pins; boom goes the power supply.

If you intend on keeping it like that for several boots, I think soldering in a temporary switch is a good idea.
Click to expand...

I'm using a standard AT power supply

Here it is:
http://www.ebay.com/itm/201631534182?_trksid=p2060353.m2749.l2649&ssPageName=STRK:MEBIDX:IT

As suggested per g4ugm, I'll update my profile with my location (I'm in Fairfax County, VA)
 
If that is the power supply you have , the power switch is already wired on it. The push on/off switch is the Light Green post at the end of the black cord.

Tom
 
hornbetw said:
Oh, that power supply is a "Dell" power supply. A lot of Dells have non-standard pin outs on the motherboard connectors.

Tom
Click to expand...

Ugh, I hope the AT connectors on that thing have the same pin outs as a standard power supply would

Still waiting for my motherboard and cpu to come in
 
amino glycine said:
Ugh, I hope the AT connectors on that thing have the same pin outs as a standard power supply would

Still waiting for my motherboard and cpu to come in
Click to expand...

Do yourself a real big favor and park that Dell power supply. From about 1998 on Dell used a standard AT type molex connector but they WIRED IT DIFFERENTLY. You will almost certainly experience a lot of smoke and it will not be good for your non-Dell motherboard.
 
Agent Orange said:
Do yourself a real big favor and park that Dell power supply. From about 1998 on Dell used a standard AT type molex connector but they WIRED IT DIFFERENTLY. You will almost certainly experience a lot of smoke and it will not be good for your non-Dell motherboard.
Click to expand...

Seriously? Great. Thanks for letting me know!
 
hello
you could also take the long road, and boot you system with Wake-On-Lan signal, from another PC on the local network.. but it is not the easy way to go ! :)
/cimon v.g.
 
I guess I can just get a cheaper ATX supply with the converter cable

But where would I get a switch? All the converters I see just have leads for one, but not a builtin one

I'm not very good at soldering or anything so I would need something that can just plug in if possible
 
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