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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: darkcoder on March 16, 2005, 03:22:10 PM
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Hello, I have an A600 where the wire connecting the LED to the motherboard has been cut (I guess it was cut when previous owners opened it). The wire was completely removed.
I would like to re-solder a new wire to make them work again.
My problem is that I don't know the meaning of pin on the motherboard. I am not expert in reading schematics, but I think that the meaning is:
1 - hard disk
2 - floppy
3 - power
4 - ground
But which is pin n.1? the leftmost or the rightmost?
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Hm, it should be very easy to find out with a multimeter/voltmeter.
Ground should be visible on the traces or the motherboard, it should be a "fat" trace. Power will always have voltage no matter what. The other two you must figure out by inserting a floppy and checking which of the two starts being pulled up (has voltage)
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Remember, the power LED on the amiga is a dualvoltage system, as it "dims" to let you know whats going on, so finding any +5V (or whatever the voltage is!) isnt going to provide that function.
Best to get hold of the schematics to find the exact points on the board.
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Eh, nope. Finding the pin that always has voltage == finding the power led Vcc. It doesn't matter if it's 5V or 2.5V or 1V. BTW, it's not /really/ a dual voltage system, it gets dimmed whenever the audio filter is on, all the blinks and stuff are just caused by (deliberately) turning the audio filter on and off.
I guess that this was originally an electrical bug on the A1000 but just looked
cool enough to keep replicating.
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Check what it says on the motherboard. Usually you always have the number "1" where the connection starts on every thing soldered to the motherboard. On the A1200 it is the leftmost that is pin 1, the pin that is facing nearest towards the pcmcia-slot. But check, I can almost promise you that it will have a number "1" printed on the board.
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@lillPip
there is no number on the motherboard.
But pins on the motherboard are surrounded by a thin white line which has an arrow-shape in the direction of the pmcia slot.
I do a small "drawing": if you look the 4 pins from above you see (each "+" is a pin):
_________
< + + + + |
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sorry, it was hard for me to describe it in english, hope it's clear
:-)
I guess that the arrow at one end means something, but does it indicate pin 1 or pin 4?
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Eh, nope. Finding the pin that always has voltage == finding the power led Vcc. It doesn't matter if it's 5V or 2.5V or 1V. BTW, it's not /really/ a dual voltage system, it gets dimmed whenever the audio filter is on, all the blinks and stuff are just caused by (deliberately) turning the audio filter on and off.
I stand corrected!
I knew about the audio filter, but didnt realise that it worked in that way... :-)
IIRC on my a1200's power LED connector, the power was to the left but im not 100% sure.
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Oh, and in my original post, sorry i was under the impression that darkcoder was looking elsewhere on the miggy mobo to pull a +5v line for the power led or something,,,,, :-P
Hence my posting about finding the correct pin, that i now can see isnt very clear heh!
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Here are the wirings:
On the motherboard:
____
<1234|
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On the keyboard (looking the metal plate, on the upper right corner are the wires):
__________
| __ |
| |23||
| |14||
| -- |
| |
| |
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Wire colours:
1: Green
2; Orange
3: Red
4: Black
________
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