installed an ATX into an emachine (was a microATX PS) but



I'm in the final phase of retrofitting an old ATX power supply
(powertech "200 watt max" model kw-6200dl3n1) into an emachines that
originally used a "micro ATX" power supply (illsan model isp 120si, "120
watt max"). all the sheet metal work and physical fitment is already
done, all the connectors are plugged in correctly, but the ATX p. supply
won't boot - its fan (and the CPU fan, and drives) don't spin and the
case front LED's don't light. in other words, "acts like a brick". I've
tried different power cords in a 'known working' outlet - same deal. all
wires connected, none 'unaccounted for'.

could this be the 'snag': the (newly installed) powertech ATX has a tiny
connector coming out of it (which has three pin positions and two wires:
black, purple, no wire) that the 'old' micro ATX ps lacks. what's the
function of that connector? presently it's just hanging in there not
connected to anything, so, can I just "jumper across it" to achieve
'power up' perhaps? or does it need to 'sense something'? it's approx
(or possibly exactly) the same size as a cd-rom connector...this tiny
connector comes 'directly out of' the power supply itself - it's not
'hanging off of' a drives power or any other connector. could it be just
a fan connector? -big mystery to me-

according to sparkle's site, an ATX has a "negative 5v"
function the miniATX lacks...and, UH-oh, a closer look reveals
a few power supply to mobo main 20pin connector pinout -differences-

below, the 'old' illsan 120 watt connector (mobo connector pin numbers).
both the same unless noted:

1. orange
2. orange
3. black
4. red
5. black
6. red - supposedly 'power plus 5 volts' on ATX
7. black
8. grey (white wire on the powertech @ pin 8) - supposedly 'power good'
on ATX
9. purple
10. yellow
11. orange
12. blue (brown wire on the powertech @ pin 12)
13. black - supposedly 'ground' on ATX
14. green - supposedly 'power on, active low' on ATX
15. black- supposedly 'ground' on ATX
16. black
17. black
18. nothing, =no= wire (blue wire on the powertech ATX @ pin 18)
19. red
20. red

so, can I just clip a wire or two to 'remove' the 'negative 5v' function
(and would that be enough to keep it from powering up, thru the front
pushbutton?) which one, or 'ones' can I do without? or is that tiny
'unknown connector' the culprit? or maybe that tiny ATX mystery
connector has a 'power up' function of some sort? maybe it's needs to be
'momentarily jumped' to power up the supply? -I got no clue-

I've tried numerous power cords, and numerous searches for more in-depth
info (and/or schematics) on both of these power supplies, or what this
tiny connector might in fact be on ANY makers power supply, to no avail.
all comment appreciated, except those advising "buy another (or bigger)

as a last resort, does anybody know where I might find 'labeled pinouts'
for what the mobo connector functions ARE on ATX and 'miniATX' I did find some guys site with a schematic for a 200w ATX,
but it did -not- include the 'mystery unknown connector' on mine...

I'd like to boot this thing...thanks in advance for tips, clues, and
educating me,


ps-have found pinouts for ATX but still can *NOT* find ANY pinouts for
power connectors for "micro ATX" power supplies ANYwhere....

-bewilderment continues-


Only 2 possibilities:
1. It is a bad psu, that does not work.
2. The mother board does not tell psu to start.

You can test it by following the procedure:
1. Unplug the psu connector to the mother board.
2. Use a paperclip to jumper the pin 14 (green) to either 13 or 15 (both
3. If the psu fan still dead, this is a bad psu.
4. If the psu fan starts, this is a problem with mother board. It can be:
1) bad mother board. 2) bad PC start button. 3) the button wire connected
to wrong location on the mother board.
5. If it is 2) bad PC start button, you can plug back psu connector to the
mother board, make a switch from the wire side of the connector. between pin
14 & either 13,15. the PC will starts working.

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