OT: Compaq power on when power returns

[Dave Liquorice]

My server is an old Compaq Deskpro EP/SB series PIII 700MHz machine. It's connected to a UPS and is configured to shutdown and power off when the UPS has been on battery for more than 60 seconds. This it does, trouble is it doesn't power back up when you cycle the power to it. Currently it needs physical prod of the power switch to bring it back to life after the shutdown/switch off and power cycle. No very convenient if there is no one about to prod it...

Remember this is an old Compaq machine and doesn't have the modern BIOS set up screens with settings to tell it what to do on power loss/return.

Any bright ideas?

[Adrian C]

There will be a jumper on the motherboard. Have a look for the maintenance manual on HP's support website, or you may be lucky and find the information about the setting written on the inside of the cover?

[Harry Bloomfield]

Dave Liquorice explained :

No - it sounds like standard behaviour for a PC, unless there are options to bypass it in the BIOS. If mine was on when the power is lost, it comes back on. If it was off when the power is lost, it remains off when the power comes back on. It sounds like you system shuts itself down in an orderly fashion - so it will stay off when the power is restored.

[Adrian C]

Scrap that, I've had a look. Nought :-(

Got anything on your network that might be sufficiently alive after a power failure to send a wake-up packet?

[Graham.]

I'd probably cobble together a little circuit, monostable, or NE555, to pulse a relay wired across the power momentary switch. Run off a separate PSU of course.

[Peter Parry]

Small wall wart PSU, resistor, capacitor and relay in series. When the mains comes back the relay closes for a bit until the capacitor charges. Use the relay contacts across the "on" switch.

[fred]

In article , Dave Liquorice writes

Has the PC supply got a +5V Standby supply? Standard momentary pushbutton power switch? Can you solder?

Here's one for that'll fit in the comp case, 2 relays, 4 diodes:

Fixed font:

+5V +5V +5V STBY MAIN STBY --- --- --- | _|_ _|_ | \ / \ / | V V | --- --- | | | | |---- | -------| ------| o- no ------| | o-| no | _|_ -o----- | _|_ -o----- _|_ | | o- nc _|_ | | o- nc ^ | | RLA ^ | | RLB / \ | | nc / \ | | --- | | o----- --- | | o- no | --- |-o----- | | --- |-o----- ------| | o- | ------| | o-----------< | | nc |--------- | ----| nc CONN PARALLEL | | | WTH MOM PWR SW --- | --- AT PANEL OR 0V | 0V MOBO HEADER |------------------------------------------------<

Diodes, 1N4148, 1N4001, any Relays, 5V coil, BT type 53 or similar

Operation:

After mains restore, +5VSTBY goes active, RLA energises & shorts power control pins. Power supply comes up, +5VMAIN goes active, energises RLB removing short from power control pins. RLB latches so that supply can be turned off manually with front panel pushbutton. Latch resets on power failure.

Cautions: Type 53 relays don't like soldering heat, best mounted on veroboard, go easy.

[Rod]

If it will respond to a Wake-on-LAN packet, you just need the router to be working. LogMeIn has WOL capability built-in - even on the free version.

[Harry Bloomfield]

Peter Parry pretended :

That sounds to be workable, but rather than an external supply...

I thought most/all PC's maintained the 5v USB supply on, whether the PC was on or not? Could that 5v not be used for the relay and timer?

[Geo]

Does it have an S6 on the motherboard?

"If you connect the computer to an electric power strip, and would like to turn on power to the computer using the switch on the power strip, set S6 to SW1 to ON."

[TheOldFellow]

Big solenoid painted yellow? Well you wanted BRIGHT ideas! R.

[dennis]

I wouldn't like to take bets on that working every time.. say the power goes and the PC does a shut down as told to do by the UPS, now the mains comes back on but the UPS is still supplying power. The PC knows nothing of the mains returning and stays off as the UPS has still been supplying power to the PC.

[Ron Lowe]

I have visions of some Wallace and Grommit like contraption, with a large brass articulated arm attached to the side of the server with a hand at the end which prods the 'ON' button...

[Clint Sharp]

In message , Graham. writes

Why a separate PSU? The PC will have +5SB so there should be little trouble tapping that. Of course, all you actually need is a small electrolytic and a suitable resistor instead of messing around with ICs.

[Dave Liquorice]

strip,

This is another problem, if the utilty power comes back before the UPS has shutdown due to low battery the power won't get cycled and the server stays powered off.

However I *think* if the UPS is told to shut down by the server in so many seconds it will power cycle it's output regardless of the utilty power returning before it has shutdown.

[Dave Liquorice]

Hopefully it's is old but being a PIII I think it will have an ATX class PSU rather than AT class which I think only went up to 386/486 based machines.

Yes, fairly sure the swich doesn't switch mains.

Oh yes.

Neat, I like relays and diodes, simple and reliable. Thanks, I was thinking of the monostable 555 timer soultion but this is better IMHO.

[fred]

In article , Dave Liquorice writes

Hope it works for you, let us know how you get on.

Forgot to say that type 53 and some other sensitive relays have polarity sensitive coils so watch your connections.

[dennis]

I don't think they do, certainly not all of them AFAICR if you tell them to shutdown they stay shut down. It means that most of the solutions probably wont work as the actual power never goes away and so can't retrigger anything when it comes on. You would need a separate supply to start the retrigger and you can't use anything on the UPS side.

[Graham.]

writes

tapping that. Of course, all you actually need is a

Yes I agree, it was just off the top of my head. Come to think of it I did a similar thing with some TV/VHS combos a few years ago. The client needed them to come on and play the tape when mains was applied without any intervention. I ended up with a single transistor with a relay in the collector and an RC timing network. Fortunately the set's software had a setting to auto-repeat. The only other mods were a pull-up resistor to force it to AV, and the tapes physically shortened and re-spliced to the end leader, so the tape rewound at the end of the programme

[dennis]

I have checked what my APC one does and you are correct, it can be told to restart when the power returns, it can also be told not to restart so make sure it is set to do what you want in the powerchute software.

My other Belkin UPS can't be shut down remotely at all AFAICT