6100 killed by Apple Extended Keyboard II :-(

[Sparky]

Hello, I put my Powermac 6100 back in service after many years. Switched on and the startup sound there. After some playing with a matching DIP switch VGA adapter I had a boot screen and the 6100 booted into the Finder.

Then I connected my Apple Extended Keyboard II and Apple mouse. These are from a 7600/166.

After turning it off and on again (power switch) the Powermac 6100 went dead. Shot all connectors correctly. No bent pins.

What can I do?

Greetings Florian

 

[macuserman]

Throw the peripherals away, get a new board to swap in?

 

[macuserman]

Joking aside I've never heard of a keyboard causing an issue like that.

 

[Sparky]

I had some starts without keyboard to set the DIP switches of the VGA adapter. Each time the Mac started. Then I got the keyboard and mouse and plugged them in.

They did not work after plugging and unplugging. So power switch off, power switch on. Only the hard disk still made noises.

 

[dcr]

Did you plug and/or unplug them in while the computer was on?

 

[Sparky]

Yes ...

 

[macuserman]

Yes ...

Oof yeah you aren't supposed to do that, I have heard of that causing problems. ADB is no dice for hot plugging. Sounds like you damaged the board.

 

[Johnnya101]

I think the service manual might say its just the ADB circuit that gets killed? It might be repairable.

 

[Unknown_K]

Do 6100's and PPC machines have fusing on the ADB lines like 68K machines do?

 

[NJRoadfan]

Does the machine have a working battery installed? The 6100 needs a "double tap" power up in order to boot if there is a dead/missing PRAM battery.

 

[David Cook]

Do 6100's and PPC machines have fusing on the ADB lines like 68K machines do?

Yes

 

[David Cook]

If you have a multimeter, measure the power supply voltages. If those are good, then check the +5V/ground on the ADB port.

 

[stepleton]

The 6100 needs a "double tap" power up in order to boot if there is a dead/missing PRAM battery.

Slight derail: what does this mean? I've only known to replace the battery --- is there an alternative?

 

[Johnnya101]

Slight derail: what does this mean? I've only known to replace the battery --- is there an alternative?

Think it means you need to turn power on and off twice quickly?

 

[MrFahrenheit]

Think it means you need to turn power on and off twice quickly?

The LC475 and PowerMac 6100 are two machines you can do this with, which both require a good PRAM battery to initialize video. The off and on quickly provides just enough power to initialize video when the power is restored.

 

[Sparky]

Ok, update. I bought a "new" working 6100 logic board (= a working 6100 machine). The battery does not have a major impact when turned on.

I have replaced the power supply of the broken machine. No boot. Unfortunately, I don't have a decent multimeter yet. So I can not test my power supply. I also do not dare to exchange the logic boards. The power supply could perhaps be the cause ... Also I don't have a schematic for the 6100 resp. the power supply unit. Are there schematics?

How could you test the mouse and keyboard? Without killing the logic board

 

[Sparky]

I have an Arduino, ESP32, some electronic parts, resistors, breadboards, ....

Is it possible to build a test circuit to test mouse and keyboard like this? That not killed my working logic board!

 

[volvo242gt]

Ok, update. I bought a "new" working 6100 logic board (= a working 6100 machine). The battery does not have a major impact when turned on.

I have replaced the power supply of the broken machine. No boot. Unfortunately, I don't have a decent multimeter yet. So I can not test my power supply. I also do not dare to exchange the logic boards. The power supply could perhaps be the cause ... Also I don't have a schematic for the 6100 resp. the power supply unit. Are there schematics?

How could you test the mouse and keyboard? Without killing the logic board

If the plastics on the chassis are good, then just swap the case lid and call it good. Use the previous 6100 as a parts computer.

Easy, by plugging the ADB cable in before turning the machine on. Then, once the cable is connected, hit the power switch. As others have said, I highly doubt the keyboard or the mouse killed the logic board. If you must test the computer without the keyboard connected, then, plug the mouse directly into the ADB port on the board and power it up. That way, you can shut it down after testing without the possibility of messing up the system files, etc.

 

[trag]

The battery advice is good. The 6100 really doesn't like to start up without a good battery. The work around is the double-power switch trip.

 

[joshc]

The work around is the double-power switch trip.

At best that should be a temporary solution though, constantly doing that is probably not great for the power supply as far as I know.

6100 logic boards tend to die because of capacitor leakage, a bad Egret or a bad 601. The 601 is really fragile, it cracks easily if the heatsink is knocked, removed improperly or if the board is handled by holding the heatsink/lifting it with the heatsink.