What have I done to my A1200? Aaaargh!

[motorollin]

I don't know what you mean by "I plugged a 4 pin plug onto the Power SW pin (2 of them)". Was this something you connected to the Mediator? All you should need is the ATX power connector and the switch from the front of the case to the two switch contacts on the Mediator. No power or switches should be connected to the A1200 motherboard or anywhere else (except your drives of course).

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moto

[motorollin]

wurzel wrote:
There is a 4 pin plug running from the ATX supply, which I plugged to the 2 pins on the Mediator, labelled Power SW. Until I did that, the miggy didn`t switch on. It`s just that the plug only sits loosely on the 2 pins & I feel as if it could fall off in time.

The 4 pin plug from the power supply has 4 wires, but 2 yellow & 2 black, so it seems to be duplicated. Maybe they go to the switch on the front?

Oh dear. This is a power plug like you would connect to a P4 connector on a motherboard. It carries 12v if the wires are yellow. If you connected that 12v supply to the power switch connector on your Mediator then you have probably damaged the Mediator.

wurzel wrote:
However, AmigaKit got back to me & explained the old switch on the front can`t be used with an ATX supply, but they do sell switches to go on the front. So I`ll have to get one of them!

If your power switch is an old AT switch (if it latches rather than being a temporary switch) then AmigaKit are correct it will not work.

--
moto

[motorollin]

wurzel wrote:
checking what I did, I plugged the 2 black wires over the pins. The Amiga simply would not switch on any other way. Is the Mediator ok, do you think?

You might be alright then. The two black wires are ground and do not actually carry any current. The two wires are probably shorted out somewhere (connected together) which is why the Amiga turned on. The black wires connected the two POWER SW pins together and had the effect of pressing the power switch.

wurzel wrote:
After much research, I find I need to order an ATX power switch to hook up, so have ordered one from AmigaKit.

Indeed to need an ATX PSU. Once you have got it fitted connect the ATX connector (the long white plug with lots of wires coming from the PSU) to the Mediator. Then find the wire coming from the power switch on the front of the case and it should have a connector on the end which will fit on the POWER SW connector on the Mediator (any way round - polarity doesn't matter as it's just a switch).

wurzel wrote:
The problem I have is that I wiped the Boot & Program disks, so I`m having to reinstall everything. I have full backups, but it`s on a USB disk which currently, I cannot access from the Amiga. So I can`t tell if the board is damaged or if the mish mash of installs on the boot disk isn`t working. The miggy hard drive light flickers as normal, but I get a blank screen (on AGA & graphics card modes on the TV/Monitor).

You may be getting the blank screen because the system is not powered correctly. Just do as above and remove all power sources other than the one to the Mediator (so pull out the original A1200 PSU and if you have one the power going IN to the motherboard floppy power connector) and then it should power on.

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moto

[motorollin]

The best way to solve problems like this is *always* to remove everything, then add components back one at a time and re-test. That would have allowed you to spot the loose SCSI card and the dodgy spider. Still, glad you tracked the problem down :-)

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moto