Conundrum-- RFI\EMI and 2.4 GHz Wireless
Straight_Man
Geeky, in my own wayNaples, FL Icrontian
XP and 98 SE box(one each for scenario effects, one which was not affected of XP kind). XP box randomly reboots, decides it is not installed right, but when you move it to another room problem vanishes-- if stereo system in other room is off. Run 98 SE box in same room, with stereo on, it cannot hook up to wireless network about 1\2 the time, and if it does it is 30-40% effective-- until rebooted\restarted, at which time 98 SE sets a default IP, loses track of DHCP, cannot find DHCP from Wireless router, router and box near router, also XP, are never affected in any way.
It cost house's owner $200.00 worht of two techs time and a 98 SE and XP reload (that was not related to this, but they had tried to Upgrade to XP near a humongous stereo and had managed to wipe 98 SE that was on that box before this visit).
Now, first thing wwas to eliminate bad power, inverted hot and cold, presence and validity of ground in power cord to computer-- power good BOTH places. That left environmental problems. AC was on, temps inside box appeared fine so long as Computer with XP freshly installed on it at my house. When I put within 10 feet of stereo, temp monitor shut down computer.
So, commonalities:
Both had Linksys 2.4 GHz wireless cards in them. That was ONLY commonality.
Hypothesis:
One teen, late teen who liked BUILDING stereo gear, had a closet full of it all hooked together. Two amps, 4 LARGE 3.5 foot high speakers, lamp cord for speaker wire connecting all this gear-- which was older, turned out NOT to sheilded to modern standards at all. In that case, as soon as we powered down computer and took it to a room sans stereo, XP reversed its decision that it had been bdly damaged, did NOT get shut down by power monitor software, FOUND the router, surfed and Windows Updated itself. Taken back into same room it malfed in with stereo off, it still found router, surfed, ftp'd, finished Updating itself with non-critical updates. This was a fresh install with virus protection, and that had been updated FIRST thing and it went to on Windows Update.
Lesson, confirmed by turning ON stereo and repeating this exercise in front of house owner and teen-- Linksys and many ohter network cards CAN act as inductive RFI\EMI intakes in presence of large Mag and RFI fields and scramble computer signals to the point that software literally shuts down computer pre-emptively claiming overheat while REAL temp at CPU is under 50 C and case is stable at 32 C. Lesson two, 98 SE under these conditions will lose track of network settings and preemptively disable card. XP tries, as far as it is concerned card is down, but card is active, confirmed at router.
Final lesson-- thou shalt NOT run thy hyper-bass- speaker-eqipped-stereo ANYwhere near a wireless NIC equipped computer. 12-30 feet away, maybe, under 10 NO.
Whole story of 25 man hours work (this was not the first visit) with VOM, inductive field amp that doubles as audible tracer for network hardwired line troubleshooting and massive frustration would be considered long by me, this is a summary. But, keep NOT thy large magnet speakers near thy computer, and near is within 8 feet if no wireless card and more like 10-12 if wireless card is in box. Some of the mysterious things happening to gear might be partly explained by this simple RFI\EMI lesson-- HTH someone, but I was told this had to be SHORT-Media so will shut up now...
Followup NOTE, second computer, the one that was running 98 SE all along, is being reloaded as it was also massively virused-- the owner of that box, NEVER updated his AV since install on October 11, 2002 (that is right, CD-ROM AV defs were all he ever had).
Followup Admin Lesson, if you have a real problem wireless box, look for RFI\EMI field near box or between box and router with thy line tracing inductive field audible AMPLIFIER handheld unit\line tracer. Easiest solution might be gating\boosting or hard wiring AROUND\PAST field with SHIELDED Cat6 cable or FIBER if it turns out to be the MUZAK amp for your elevator and possibly office, or the office paging\music system or LARGE refurbed phone system panel.
John.
It cost house's owner $200.00 worht of two techs time and a 98 SE and XP reload (that was not related to this, but they had tried to Upgrade to XP near a humongous stereo and had managed to wipe 98 SE that was on that box before this visit).
Now, first thing wwas to eliminate bad power, inverted hot and cold, presence and validity of ground in power cord to computer-- power good BOTH places. That left environmental problems. AC was on, temps inside box appeared fine so long as Computer with XP freshly installed on it at my house. When I put within 10 feet of stereo, temp monitor shut down computer.
So, commonalities:
Both had Linksys 2.4 GHz wireless cards in them. That was ONLY commonality.
Hypothesis:
One teen, late teen who liked BUILDING stereo gear, had a closet full of it all hooked together. Two amps, 4 LARGE 3.5 foot high speakers, lamp cord for speaker wire connecting all this gear-- which was older, turned out NOT to sheilded to modern standards at all. In that case, as soon as we powered down computer and took it to a room sans stereo, XP reversed its decision that it had been bdly damaged, did NOT get shut down by power monitor software, FOUND the router, surfed and Windows Updated itself. Taken back into same room it malfed in with stereo off, it still found router, surfed, ftp'd, finished Updating itself with non-critical updates. This was a fresh install with virus protection, and that had been updated FIRST thing and it went to on Windows Update.
Lesson, confirmed by turning ON stereo and repeating this exercise in front of house owner and teen-- Linksys and many ohter network cards CAN act as inductive RFI\EMI intakes in presence of large Mag and RFI fields and scramble computer signals to the point that software literally shuts down computer pre-emptively claiming overheat while REAL temp at CPU is under 50 C and case is stable at 32 C. Lesson two, 98 SE under these conditions will lose track of network settings and preemptively disable card. XP tries, as far as it is concerned card is down, but card is active, confirmed at router.
Final lesson-- thou shalt NOT run thy hyper-bass- speaker-eqipped-stereo ANYwhere near a wireless NIC equipped computer. 12-30 feet away, maybe, under 10 NO.
Whole story of 25 man hours work (this was not the first visit) with VOM, inductive field amp that doubles as audible tracer for network hardwired line troubleshooting and massive frustration would be considered long by me, this is a summary. But, keep NOT thy large magnet speakers near thy computer, and near is within 8 feet if no wireless card and more like 10-12 if wireless card is in box. Some of the mysterious things happening to gear might be partly explained by this simple RFI\EMI lesson-- HTH someone, but I was told this had to be SHORT-Media so will shut up now...
Followup NOTE, second computer, the one that was running 98 SE all along, is being reloaded as it was also massively virused-- the owner of that box, NEVER updated his AV since install on October 11, 2002 (that is right, CD-ROM AV defs were all he ever had).
Followup Admin Lesson, if you have a real problem wireless box, look for RFI\EMI field near box or between box and router with thy line tracing inductive field audible AMPLIFIER handheld unit\line tracer. Easiest solution might be gating\boosting or hard wiring AROUND\PAST field with SHIELDED Cat6 cable or FIBER if it turns out to be the MUZAK amp for your elevator and possibly office, or the office paging\music system or LARGE refurbed phone system panel.
John.
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