Power supply can be tested separately - albeit more complex
- as demonstrated by that site that also provided voltage
chart:
http://www.hardwaresite.net/faqpowersupply.html
Motherboard is rather more complex. But power supply
controller function on motherboard can be observed by
monitoring those purple and green wire voltages.
How a motherboard is damaged can reveal other problems. For
example, if a motherboard is mounted using multiple conductive
standoffs, then more potentially destructive paths exist for a
common mode surge - numerous points of damage. Single point
conductive standoff near power connector makes a motherboard
more resilient to surge damage and even crashes due to static
electric shocks.
Power supplies must contain overvoltage protection as
required 30 years ago and by Intel specs. However if that OVP
is not installed in power supply (and it usually does not
exist in sub $80 power supplies), then a power supply failure
or a failure caused by external events may easily destroy all
ICs on motherboard, hard drive, RAM, etc.
It is not possible without detailed technical documents to
determine if motherboard verses CPU are damaged. Only way is
to test each in another known good system. BTW, previous test
using only motherboard and power supply assumed CPU was also
installed.
Surges form a path through system. Only when a part has
both incoming and outgoing path, can that part be damaged.
Classic example of surge damage is incoming on AC electric,
bypassing power supply using a direct connection from AC
electric wire to chassis, through motherboard ground plane and
modem, then outgoing on phone line to earth ground. Only item
typically damaged is modem's DAA section - often the off hook
relay or current limiting resistors. Classic error message is
'No Dialtone Detected'.
Motherboard IC were all exposed to same surge. But
motherboard ICs had no outgoing surge path - therefore not
damaged. That isolation is an important reason by some parts
can be damaged and others are not.
However a power supply overvoltage can literally damage most
every IC on motherboard, disk drive, etc. This failure is so
catastrophic that all power supplies must have OVP - although
too many have no such function to sell at less than $80.
This gives but some idea how system destruction could
happen. If simply an AC mains surge, then damage would be
limited. However if power supply did not have OVP, then
damage could be to everything - except maybe CPU that has its
own voltage regulator. Just some ideas of how to determine
what is damaged - and why.
Richard wrote:
> "w_tom" <> wrote in message
> news:...
>> 1) You are confusing power outages with surges. Two different
>> electrical events. Power outages may result from a
>> destructive surge. But surges occur typically once every
>> "eight" years. How often are power outages?
>
> No, I'm not confusing outage with surge. The event was a power
> outage, and judging from the smell coming from my Dell GX110
> was immediately preceeded by a pretty good surge. We've had
> other outages without incident. Local power authority says that
> this outage was caused by the loss of a major power line.
>
> Neighbors say outages in our neighborhood average about six
> a summer. Average duration, about an hour.
>
> That said, I'll immediately look into having "whole house"
> protection put in place, and I thank you for bringing this up
> and explaining it so clearly.
>
>> Motherboard is gone because no surge protector made a less
>> than 10 foot connection to the most critical 'system'
>> component - surge protection - single point earth ground.
>
> Next stupid question of mine: Does "motherboard gone" mean
> motherboard, CPU, RAM, and possibly the disk controllers
> are all gone?
>
> Thanks for the reference to the discussion at alt.cert*.a-plus.
> I've just started reading it, and it looks very informative.
>
> Best regards,
> Richard
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