Mac OS 9 Lives

Mac OS 9 Discussion => Hardware => Topic started by: velvetcave on June 25, 2023, 02:41:06 AM

Title: Question regarding remote power up of G4 MDD
Post by: velvetcave on June 25, 2023, 02:41:06 AM
Hi, wondering if anyone here can help.
I currently have 2 G4 MDDs, one fully functional and one that doesn't boot that I keep for spares.
For reasons of fan noise I have to have my functioning G4 in a different room so ideally I'd like to be able to start the thing up remotely.
Someone here came up with the idea of running a 10 pin male to female IDC cable from the power switch module on the defunct G4 to the IDC cable in the functioning one.
I got a 2m IDC cable and this works as expected, but after a random period of time the G4 crashes. This can be after a few minutes or an entire day.
Any guidance, advice, or "stop doing that, you'll break it!" instructions very gratefully received.
Functioning G4:
PowerPC G4 1.25 GHz
model number: M8570
2 Gb ddr sram
os9.2.2
pro tools v 5.1.1
888 [24] io
Core and farm card

Non functioning G4:
PowerPC G4
model number M8570
To be clear, I don't know why the non-functioning G4 doesn't work, the power switch module seems OK though.
Thanks.

Title: Re: Question regarding remote power up of G4 MDD
Post by: ssp3 on June 25, 2023, 06:54:17 AM
IIRC, start-up button on Macs always was just shorting one particular pin/pad to ground. Just solder (screened) 2 wire cable in paralel to existing micro switch and put a momentary push button switch at the end of it.
Title: Re: Question regarding remote power up of G4 MDD
Post by: ovalking on June 25, 2023, 12:51:39 PM
The power switch on some Macs can be locked into the On positon. In such cases you could then use a remote control power socket.
Title: Re: Question regarding remote power up of G4 MDD
Post by: DieHard on June 25, 2023, 01:22:37 PM
You can get an original cinema display and use it's touch button, but don't know if the ADC cable will be long enough
Title: Re: Question regarding remote power up of G4 MDD
Post by: robespierre on June 25, 2023, 02:30:45 PM
It isn't possible to simply power on the machine using the keyboard?
Title: Re: Question regarding remote power up of G4 MDD
Post by: IIO on June 25, 2023, 10:28:54 PM
if you need a cable for USB solutions anyway, why not just remove the power button incl. the control PCB of the machine using a long cable?
Title: Re: Question regarding remote power up of G4 MDD
Post by: ssp3 on June 25, 2023, 11:48:58 PM
if you need a cable for USB solutions anyway, why not just remove the power button incl. the control PCB of the machine using a long cable?

PCBs that I have seen have some sort of chip and quartz oscillator on them. Good luck running clock signal for more than a few feet.

https://forums.macrumors.com/threads/g4-power-switch-panel-pinout.417971/
Title: Re: Question regarding remote power up of G4 MDD
Post by: peeperpc on June 26, 2023, 01:15:56 AM
One of those remote button pushers? You may place the face of the MDD against the wall if you want to avoid using adhesive tape.

Title: Re: Question regarding remote power up of G4 MDD
Post by: refinery on June 26, 2023, 03:30:14 PM
It isn't possible to simply power on the machine using the keyboard?

Depends on the machine. At some point they stopped supporting this but I can't remember when... At the very least though, you'd be limited to the small keyboards that shipped with green and white or early g4s, those were the only ones with power buttons on them
Title: Re: Question regarding remote power up of G4 MDD
Post by: velvetcave on June 28, 2023, 03:08:28 AM
You can get an original cinema display and use it's touch button, but don't know if the ADC cable will be long enough
Thanks, I did look into this as it has been suggested before, unfortunately I'd need about 3m of ADC cable and I can't find an extender.
Title: Re: Question regarding remote power up of G4 MDD
Post by: velvetcave on June 28, 2023, 03:11:33 AM
It isn't possible to simply power on the machine using the keyboard?
Not this model unfortunately
Title: Re: Question regarding remote power up of G4 MDD
Post by: velvetcave on June 28, 2023, 03:13:18 AM
if you need a cable for USB solutions anyway, why not just remove the power button incl. the control PCB of the machine using a long cable?
That's essentially what I did, just without physically removing the power button and pcb from the defunct G4.
Title: Re: Question regarding remote power up of G4 MDD
Post by: velvetcave on June 28, 2023, 03:15:21 AM
if you need a cable for USB solutions anyway, why not just remove the power button incl. the control PCB of the machine using a long cable?

PCBs that I have seen have some sort of chip and quartz oscillator on them. Good luck running clock signal for more than a few feet.

https://forums.macrumors.com/threads/g4-power-switch-panel-pinout.417971/
This is effectively what I did. Presumably the distance of the cable run is too great? Why would the power button need clock signal?
Title: Re: Question regarding remote power up of G4 MDD
Post by: velvetcave on June 28, 2023, 03:16:24 AM
One of those remote button pushers? You may place the face of the MDD against the wall if you want to avoid using adhesive tape.
Thanks, I think it will have to be this!
Title: Re: Question regarding remote power up of G4 MDD
Post by: ssp3 on June 28, 2023, 04:13:56 AM
Why would the power button need clock signal?

Not the button, but the whole assembly. Why? Ask Apple. ;) Why do it simple, if you can do it in a complicated way.*


----
* What used to be a simple 10 cent capacitor job in analog domain, now requires a computer, OS, proper algorithm and someone who can write it  ;D
Title: Re: Question regarding remote power up of G4 MDD
Post by: IIO on June 28, 2023, 05:13:07 AM
i was about to ask if it is maybe possible to only extract only the knob and extend its cable, but was somehow suspecting that it is a bad idea and also depends on the board or how it communicates with the power mananger unit of the PC.

that physical knob pressing knob looks sexy - but does it run with battery or does it need a power adapter?
Title: Re: Question regarding remote power up of G4 MDD
Post by: peeperpc on June 28, 2023, 09:39:36 AM
that physical knob pressing knob looks sexy - but does it run with battery or does it need a power adapter?

All I've seen use a battery (mostly CR2). They operate via Bluetooth. Some of them also have a WiFi hub option that sends Bluetooth to pusher units in case you want to control them through WiFi/internet.
Title: Re: Question regarding remote power up of G4 MDD
Post by: IIO on June 28, 2023, 10:55:58 AM
i suppose it is clocked because they find out the duration of the press and determinig doubleclick vs singleclick this way.

(and of course because it is apple)
Title: Re: Question regarding remote power up of G4 MDD
Post by: GaryN on June 28, 2023, 01:51:20 PM
Why would the power button need clock signal?
Not the button, but the whole assembly. Why? Ask Apple. ;) Why do it simple, if you can do it in a complicated way.*
----
* What used to be a simple 10 cent capacitor job in analog domain, now requires a computer, OS, proper algorithm and someone who can write it  ;D

If any of you own or have owned a QS or MDD or DA or any other Mac desktop with a power button on the front you must know (or should know) that when the machine crashes and locks up, you force a shut down by pressing and holding the power button.
There is a defined "duration of press" required to do that to prevent accidental data loss.
Title: Re: Question regarding remote power up of G4 MDD
Post by: robespierre on June 28, 2023, 02:22:39 PM
It's not just desktops. PowerBooks all used the power button to force a reset if it is held down for a few seconds: this is just a GPIO signal that the SMC/PMC interprets and it is in control of all the power and reset functions.

Reading the macrumors thread, the chip that people are talking about has nothing to do with the power or reset buttons. Its sole purpose is making the light "throb" when the computer is sleeping.
Title: Re: Question regarding remote power up of G4 MDD
Post by: IIO on June 28, 2023, 11:41:59 PM
well that is how f.e. keyboards work, (including pre-usb.)

for a single button application one might think that there are alternatives, but they might have a good reason. more reliable, or whatever.