Has my A3000 died?

[Gwion]

I opened my A3K today to replace its HD. I took the LEDs off to re-solder them.
I put the put the LEDs on when the machine was on then the connections of the HD led hit the metal case of the machine and it sparked then the machine went off.
The PSU powers when not connected to the mobo but when its plugged into the mobo it doesnt power.

[CLS2086]

rework is needed, send the motherboard to JJB at Amigacenter.

[Oli_hd]

I think there is a transistor driving the LED on the A3K, its probably gone open circuit, find the transistor and change it.

I have to say Ive been lucky as Ive shorted most of my Amiga's against the case one way or another and after an hour max the machine turns on and is fine, guess Ive just been lucky

EDIT----
Ok after looking it was a 7407 and it was resistor protected.
But it seems they didnt protect the 5V power.
it goes 5V+ ---- LED ---- resistor ---- 7407 chip.
So if you shorted the 5V to ground then it was a direct short, check if the PSU is outputting 5V still and then check a chip to see if its getting 5V.
There is no fuse protecting the main 5V line from what I can see.

[amiga_3k]

Disonnect the HD/Power LED's from the motherboard and see what happens.

[Gwion]

Oh i'll leave it for a hour then i'll check of disconnecting the HD/Power LEDs will fix it.

[Gwion]

Got bored of waiting for a hour so i tried the PSU on the mobo abit loose and the A3K boots.
But when i put it on fully it doesnt  :-?
Any ideas?

[amiga_3k]

Take the mobo out (I know, it's an a lot of work) and clean underneath it. Seems like your mobo may contact with the chassis. Also, you might first try cleaning the connector with contact-cleaner and tighten the bushes a bit.

[Gwion]

Ok will do

[rkauer]

 Also check if one of those pins in the power connector had not coming loose from the motherboard (cold joint).

[Gwion]

Took out the motherboard no cold joints.
Connected my A2000's PSU to the motherboard and still the same.
Dont know what else to do.

[Tenacious]

Oli_hd is right.  The 7407 (U352, an inverter) switches the ground side of the LED through a 56 ohm resister (R300).  The cathode is tied directly to a branch of the +5V rail.

Can you get your hands on a meter and check the power supply for +5V?  Check the little board with LEDs for +5V?  Check where the wires from that board ties to the MB?  Check this branch all the way to where it is supplied with +5V by the Power supply connector?  If you burned out a skinny +5V trace that supplies the LED and several chips, you will have to solder in a new wire to re-supply this branch with +5V.

It's sorta like heart bypass surgery.  Grin.

You didn't put the LED in backwards?

[Gwion]

Accident  :-(

[Tenacious]

Let us know how this goes.  I think this is repairable.

[Gwion]

I replaced the PSU and guess what?!?!?
It doesnt work!!! :madashell:  :madashell:

[Gwion]

only Joking it fixed it  :-D