Gabriel said:
Thank you very much Paul and SC Tom for the intense google searching for a
BaD MoThErBOard I ended up finishing this mobo with my forgotten Driverpack
Solution 12.3 Final like Jan reccomended its like 3.13 Gig in size and found
all three of the drivers needed as for the IEEE I cant see it then but I
forgot I already had a 2x firewire pluged in and installed in the case using
both of the motherboards two (ports?) pin array so I pulled one out looked
at it and didnt know the pin settings because the manual is different to the
AtecStar as pin 9 was nc and pin 10 was ?? so I put it back - - the job was
for a repairs centre and firewire as I know wont be used so the card readers
firewire was not pluged in if they realy needed it it was on the back of the
pc so I apologise for all this searching to get IEEE working for me and
forgetful me already had it!! From SC Toms manual I was able to use the usb
pins for the card reader and tested it with a 128mb guinea pig flash drive
to see if it would work or burn luckily it worked.
There was one thing about this AtecStar board and that was that it would not
100% always turn on from pressing the power button sometimes it would power
up and have the fans spin but there was only a black monitor screen,
sometimes shutting down the pc in windows wouldnt work till the power button
was pressed (at the windows is now shutting down - usually the last this you
see) that got me to test the power supply with my useful tester (bought from
ebay) nothing wrong, I tried with another power supply and still the
same?!?!? nothing wrong with the ram as far as memtest 86+ after 3 rounds,
the cpu?? or this board was a bit faulty, no caps buldging or bent. Is this
board just faulty or a cheap board I saved them from using this pc as it had
to many problems in the start to be a safe working money maker and the
second hand HDD I had was not up to my trusting standards its a good thing
because it was making way to much read/write noise only after I finished it
with all updates and AV plus more. SC Tom if you want to get out your old
boards I hope they dont have as much dust as the AtecStar had at its
begining of its refurbishment for somehow the pc case had no case fan it
must of been about five to six maybe more years worth of dust I guess that
is why the power on and off isnt fully working.
Ok long post guys but thanks again for the help.
Based on symptoms (changed ATX supply and symptoms did not change),
it suggests the motherboard PS_ON# driver isn't working well.
You can access the electrical connections on the main motherboard
power connector, while the cable is plugged in. The plastic shell
on the 20 or 24 pin main connector, is open at the back. You can push a
multimeter tip into each of the individual cells of the main connector,
and make electrical contact with the pin in there. By doing that,
you can get a voltage measurement.
Set your multimeter to volts, maybe 20V scale would be good. (My meter has
2, 20, 200, and 20V is the closest.) Clip the black voltage lead of the
multimeter, to a chassis screw, like a screw on an I/O connector on the
backplate area. This frees up a hand you can use to hold the red probe
and take measurements.
You want to check the voltage on the PS_ON# pin. See page 30.
http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf
When you plug in the PC, and then flip on the switch at the back,
you get +5VSB delivered to the motherboard. The motherboard PS_ON#
driver is open collector, and there is at least a pullup resistor
on the ATX supply end. With the multimeter, with the PC still not
running, the voltage should be 5V.
When you push the power button on the front, that's a momentary
contact switch. That does not connect directly to the PS_ON# line.
The front switch, goes to a logic chip on the motherboard. The
momentary pulse from the front switch, is "latched" by the logic
and converted to a steady level on PS_ON#. The open collector
driver on the motherboard, should drive PS_ON# to between 0.4 and
0.8V. That is a "logic low", and the "#" symbol in the PS_ON# signal
name, means it is "active low". So when the line voltage there
drops to 0.4 to 0.8 V or so, the power supply should turn on.
At the end of your computing session, the computer wishes to shut down.
The command causes the logic on the motherboard to deassert PS_ON#.
The voltage rises back to +5.0V again.
Failure to go through those state transitions, can hint at the
defect. It could be a bad motherboard. If you really wanted to
know, you'd use a 20 pin extender cable, one you can afford to
cut up, and interrupt the PS_ON# signal by cutting it in half.
Strip the ends, so you have electrical connections to work with.
Doing that, allows you to check whether the computer goes
off when the wire connection is opened. And, whether the voltage
on the PSU end of the line, rises to +5V by itself. That's
also a test you can do on the PSU while it is completely
disconnected from the motherboard. The PS_ON# line should be
resting at +5V, when the main power connector is not connected
to anything, but the supply is plugged in to the wall (and switched
on at the back).
HTH,
Paul
