pc power supply ground reading

[Tanya]

baby-at pc (p8 and p9 connectors -- total 12 wires to the motherBoard)
the innerMost black grounds read -0.01 volts not zero (the outer grounds
read zero)
also the grounds on the connectors (for ex to the hd) read -0..01 volts
shouldn't ground be ZERO?
thanks

 

[JW]

On Wed, 31 Dec 2003 13:20:33 -0500 Tanya
<tjtmdREMOVE_THIS@attglobal.net> wrote in Message id:
<3FF31371.FC1969F4@attglobal.net>:

baby-at pc (p8 and p9 connectors -- total 12 wires to the motherBoard)
the innerMost black grounds read -0.01 volts not zero (the outer grounds
read zero)
also the grounds on the connectors (for ex to the hd) read -0..01 volts
shouldn't ground be ZERO?

For all intents and purposes for what you are measuring -0.01 volts is
zero. 10mv isn't worth worrying about. Be aware that those old AT style
connectors aren't too reliable, however. I've seen 'em lose three tenths
of a volt through the connector on older systems which CAN cause
problems.

 

[Tanya]

JW wrote:

On Wed, 31 Dec 2003 13:20:33 -0500 Tanya
tjtmdREMOVE_THIS@attglobal.net> wrote in Message id:
3FF31371.FC1969F4@attglobal.net>:

baby-at pc (p8 and p9 connectors -- total 12 wires to the motherBoard)
the innerMost black grounds read -0.01 volts not zero (the outer grounds
read zero)
also the grounds on the connectors (for ex to the hd) read -0..01 volts
shouldn't ground be ZERO?

For all intents and purposes for what you are measuring -0.01 volts is
zero. 10mv isn't worth worrying about. Be aware that those old AT style
connectors aren't too reliable, however. I've seen 'em lose three tenths
of a volt through the connector on older systems which CAN cause
problems.

thank you very much for the reply!
both grounds on the power connectors (at least for the drives) are -.01 volts

is this what you are referring to?
functionally, the pc's problems could be blamed on a faulty psu (1993)
and before further testing it i was concerned that the grounds to the
connectors were not zero...
thanks and happy new year
sincerely
Tanya

 

[JW]

On Wed, 31 Dec 2003 18:17:30 -0500 Tanya <tjtmdOMIT_THIS@attglobal.net>
wrote in Message id: <3FF3590A.693FDD93@attglobal.net>:

JW wrote:

On Wed, 31 Dec 2003 13:20:33 -0500 Tanya
tjtmdREMOVE_THIS@attglobal.net> wrote in Message id:
3FF31371.FC1969F4@attglobal.net>:

baby-at pc (p8 and p9 connectors -- total 12 wires to the motherBoard)
the innerMost black grounds read -0.01 volts not zero (the outer grounds
read zero)
also the grounds on the connectors (for ex to the hd) read -0..01 volts
shouldn't ground be ZERO?

For all intents and purposes for what you are measuring -0.01 volts is
zero. 10mv isn't worth worrying about. Be aware that those old AT style
connectors aren't too reliable, however. I've seen 'em lose three tenths
of a volt through the connector on older systems which CAN cause
problems.

thank you very much for the reply!
both grounds on the power connectors (at least for the drives) are -.01 volts

is this what you are referring to?

Yes. There is no problem in your system with regards to your ground
measurements. Are you having a problem with the system under test? If
so, can you elaborate on what the problem is?

functionally, the pc's problems could be blamed on a faulty psu (1993)
and before further testing it i was concerned that the grounds to the
connectors were not zero...

If you have a power supply issue, I'd be more concerned with the voltage
outputs of +5 and +12, and not the grounds, if you're measuring only a
10mv difference between them.

thanks and happy new year

You're welcome, and you too!

 

[Tanya]

thanks again for replying!
well there are a lot of issues with the pc i'm not sure whether it's safe to even
try to troubleShoot
i did find (and correct) 1 problem : the 3 v lithium battery wasn't making contact
(* 3 batteries) however a different part number *cured* the date and time loss
(i.e. a thicker 3 v li battery than it had arrived with)
however now it's stating hd failure + / - hdc failure and the floppy hasn't and
still doesn't read proven boot diskS....
"drive not ready"
fdc failure
(btw it has a ?vesa i/o card and at times the mouse doesn't work (doesn't show up)
in the cmos settings which is also attached to same card)
there're many other errors EXCEPT for RAM errors...
plus the case fan is not working.
i have to remove all cards, since the fan did work -- (btw this could be memory
however afaik RAM problems don't CAUSE a fan to stop running (although the reverse
happens))
and it hasn't given any memory errors <YET>
my major concern is the psu
i don't want to <further> damage it especially since the grounds 2 of the 4 are
0.00 and 2 of the 4 are - 0.01
(both p8 and p9's innerMost wires are -0.01)
probably will try another *working* psu
i apologize b/c i don't know if it's ok to post this *saga* LOL here or in a pc
group.
if you have suggestions please don't hesitate




JW wrote:

On Wed, 31 Dec 2003 18:17:30 -0500 Tanya <tjtmdOMIT_THIS@attglobal.net
wrote in Message id: <3FF3590A.693FDD93@attglobal.net>:



JW wrote:

On Wed, 31 Dec 2003 13:20:33 -0500 Tanya
tjtmdREMOVE_THIS@attglobal.net> wrote in Message id:
3FF31371.FC1969F4@attglobal.net>:

baby-at pc (p8 and p9 connectors -- total 12 wires to the motherBoard)
the innerMost black grounds read -0.01 volts not zero (the outer grounds
read zero)
also the grounds on the connectors (for ex to the hd) read -0..01 volts
shouldn't ground be ZERO?

For all intents and purposes for what you are measuring -0.01 volts is
zero. 10mv isn't worth worrying about. Be aware that those old AT style
connectors aren't too reliable, however. I've seen 'em lose three tenths
of a volt through the connector on older systems which CAN cause
problems.

thank you very much for the reply!
both grounds on the power connectors (at least for the drives) are -.01 volts

is this what you are referring to?

Yes. There is no problem in your system with regards to your ground
measurements. Are you having a problem with the system under test? If
so, can you elaborate on what the problem is?

functionally, the pc's problems could be blamed on a faulty psu (1993)
and before further testing it i was concerned that the grounds to the
connectors were not zero...

If you have a power supply issue, I'd be more concerned with the voltage
outputs of +5 and +12, and not the grounds, if you're measuring only a
10mv difference between them.

thanks and happy new year

You're welcome, and you too!