Computer freezes-up at start-up -- necesssary to restart for normal operations.

[socraticquest]

Hello,

Upon start-up, the cursor does not respond to the mouse. Hence, it's
necessary to restart the computer (a second-time) for normal
operations.

One thing I noticed (before I had replaced a failed power supply) was
that the computer only sometimes "froze-up" at start-up.

After the failed power supply was replaced, the computer always
freezes-up at start-up.

The power-supply literally blew-out (I smelled an 'ozone-like" smell
when I went to replace the power-supply).

So it seems that the computer "freeze-up" at startup is likely been a
hardware-related problem. What can be done to fix this problem?

Thank-you

 

[pjp]

Hello,

Upon start-up, the cursor does not respond to the mouse. Hence, it's
necessary to restart the computer (a second-time) for normal
operations.

One thing I noticed (before I had replaced a failed power supply) was
that the computer only sometimes "froze-up" at start-up.

After the failed power supply was replaced, the computer always
freezes-up at start-up.

The power-supply literally blew-out (I smelled an 'ozone-like" smell
when I went to replace the power-supply).

So it seems that the computer "freeze-up" at startup is likely been a
hardware-related problem. What can be done to fix this problem?

Thank-you

Power supply failure. No way can really tell if it didn't also damage
motherboard leaking extraneous voltages. Based just upon that alone, I'd be
suspecting such and thinking another motherboard given you've changed to a
presumably good power supply. Hard to diagnose without some replacement
parts swapping.

 

[Paul]

Hello,

Upon start-up, the cursor does not respond to the mouse. Hence, it's
necessary to restart the computer (a second-time) for normal
operations.

One thing I noticed (before I had replaced a failed power supply) was
that the computer only sometimes "froze-up" at start-up.

After the failed power supply was replaced, the computer always
freezes-up at start-up.

The power-supply literally blew-out (I smelled an 'ozone-like" smell
when I went to replace the power-supply).

So it seems that the computer "freeze-up" at startup is likely been a
hardware-related problem. What can be done to fix this problem?

Thank-you

There is one brand of power supply, in particular, to watch out for.
The Bestec brand supplies, certain models of those have one rail
"go to a high voltage" upon failure. This has been known to ruin
the motherboard, and even the hard drive.

Most supplies have a label on the side, and the brand of the
supply may be printed on there. Googling the brand or the
model number, may present you with more horror stories.

In many other cases, other power supply brands can fail, but the
rest of the system will survive. So just because a power supply fails,
doesn't mean "everything goes in the garbage". If you were
using one of those poorly designed Bestec supplies that overvolt,
then you'd want to do more component level testing, to see
what parts of the system are still good.

*******

It could be, that the mouse has failed. If the mouse has a
PS/2 connector, it can be damaged by plugging and unplugging
the thing, while the DC power is still on. PS/2 plugs are
not "hot plug compatible". USB plugs are, for comparison.
They have staggered contact design, to sequence the power
properly, and allow relatively safe plug and unplug.

In this sample image, you can see how the USB power pins,
are longer than the D+ and D- data pins, and that helps
protect the USB device during plug and unplug.

http://usb3.com/images/usb3_dia.jpg

Paul

 

[socraticquest]

There is one brand of power supply, in particular, to watch out for.
The Bestec brand supplies, certain models of those have one rail
"go to a high voltage" upon failure. This has been known to ruin
the motherboard, and even the hard drive.

Most supplies have a label on the side, and the brand of the
supply may be printed on there. Googling the brand or the
model number, may present you with more horror stories.

In many other cases, other power supply brands can fail, but the
rest of the system will survive. So just because a power supply fails,
doesn't mean "everything goes in the garbage". If you were
using one of those poorly designed Bestec supplies that overvolt,
then you'd want to do more component level testing, to see
what parts of the system are still good.

*******

It could be, that the mouse has failed. If the mouse has a
PS/2 connector, it can be damaged by plugging and unplugging
the thing, while the DC power is still on. PS/2 plugs are
not "hot plug compatible". USB plugs are, for comparison.
They have staggered contact design, to sequence the power
properly, and allow relatively safe plug and unplug.

In this sample image, you can see how the USB power pins,
are longer than the D+ and D- data pins, and that helps
protect the USB device during plug and unplug.

http://usb3.com/images/usb3_dia.jpg

    Paul- Hide quoted text -

- Show quoted text -

On the topic of power supply units. The new power-supply unit produces
interference with AM radio stations. The previous power-supply unit
did not produce radio interference.

What is the advice on power supply units that produce radio
interference?

thanks

 

[socraticquest]

Switching power supplies do produce harmonics by their very nature, which
can extend up into the radio frequency bands, but it sounds like yours isn't
as well filtered as the previous one was.   Did you change brands?- Hide quoted text -

- Show quoted text -

Yes, the power-supply is a different brand.

 

[glee]

Yes, the power-supply is a different brand.

What brand and model Power Supply did you buy?

 

[Paul]

Yes, the power-supply is a different brand.

Power supplies, have some filter components, just after the
point where the line cord enters the power supply.

There is a schematic of a PC supply here. The components just
before the diode bridge, are there to filter noise. T1, T5,
C4, C2, C3. Some of those components are physically large,
making it a bit easier to spot them inside the power supply.

http://www.pavouk.org/hw/en_atxps.html

Normally, those components would be enough to allow the
supply to meet FCC specifications. The FCC sets rules, for
how much RF interference equipment can produce.

You could try to fix the problem, using a filter like this.
But really, it's not your responsibility, to spend money
to correct a manufacturing defect. And these filters,
actually cost more than your average good quality
ATX power supply! It's much cheaper, if the power supply
manufacturer, puts them inside the supply for you. You would
fit a filter like this, right next to the power supply line
cord input (taking care to build a box to hold this
thing, so no one can touch the AC terminals).

http://cor.com/Series/PowerLine/N/

---> Return the supply and get another one. <---
That's the only way to send the message,
we won't accept crap.

I've had an Antec brand supply do that, and
even the fancy brands can have that problem. Mine
put noise (herringbone pattern) on the TV set. And
to my shock, when I opened it up, I did find there
were filter components in place, so there is something
else wrong with that design. (The filter should have
removed the residual noise.) The Antec supply produces so
much interference, it causes my ADSL modem to lose sync
and drop the line! The ADSL modem and Antec supply,
happened to be plugged into the same power strip.
With the Antec removed from the picture, my modem
has returned to being rock solid. Now, that's a
noisy supply. That's what happens when it's really
bad.

Paul