We had lightning hit across the street from us and my PC got zapped along
with other items in the house. Yes, I had twosurgesuppressors to no avail..
First, those surge protectors did exactly what the manufacturer
claims. Does a protector stop surges? Well open one up. Notice a
direct connection from AC mains to computer. Nothing (other than a
circuit breaker and copper conductors) is between computer and AC
mains. Protectors too far from earth ground and too close to
computers may even contribute to computer damage.
Second, what was the path from AC mains to earth ground? Everything
in that path conducted a destructive surge. But only one or some
parts suffer damage. We know, for example, that memory would not be
damaged. Memory has an incoming path for electricity (the surge) but
no outgoing path.
Third, better computer manufacturers provide comprehensive hardware
diagnostics just for your problem. Your's is homebuillt. Motherboard
manufacturers typically provide no diagnostics even though diagnostics
exist and could have been provided for free. Download diagnostics
from each hardware component manufacturer or third party
diagnostics. For example, was harm to the video controller? Did
that video controller manufacturer provide diagnostics?
Collect facts so that others with more knowledge can post a useful
reply. Also important are facts from Device Manager and from system
(event) logs. What do they report?
Those who know hardware can routinely restore a lightning damaged
computer. Trick is to follow the surge path; identify then test the
suspects. For example, assume a surge was incoming on AC mains with
two surge protectors. Those surge protectors diverted a surge on AC
hot (black) wire to other AC wires. Now a surge can enter the
motherboard - bypass surge protection found inside all power
supplies. That is a likely incoming surge path made easier by
protectors located too close to the motherboard.
What is the outgoing path to earth? Outgoing paths could be network
card, telephone modem, table top (yes things like wood and concrete
are electrical conductors to surges), mouse cord touching something
conductive, etc. Identifying all possible outgoing paths, then
execute hardware diagnostics on those potential suspects.
This much is known. Surge must first flow in everything in a path
from incoming (ie AC electric) to outgoing (ie earth ground). No
incoming and outgoing means no surge damage. What was in that path?
Those are your suspects that require hardware diagnostics or
analysis. Again, also obtain facts from system logs and other
hardware reports.
Meanwhile, those two surge protectors did exactly what the
manufacturer claimed. Effective computer protection means surges do
not enter a building. Surges that are earthed before entering a
building do not overwhelm protection already inside all computers. If
those two surge protectors were adjacent to the computer, then the
surge was offered even more paths to earth, destructively, via that
computer. One ‘whole house’ protector would have made that computer
(and all other appliances) better protected. The superior solution
also costs less money.
Learn from the experience. Also learn what the incoming and
outgoing surge path was through the computer. Then install a 'whole
house' protector or upgrade the earthing of that incoming path so that
a surge does not enter the building that way again.
