Specifically, you go from mediocre protection to virtually zero protection
doing what you did, so don't feel too guilty. :-)
> try to connect it won't get a dialtone now. If i have it hooked it up to
> surge protector, when i push the voice/data switch i hear nothing.
> you hear a dialtone). when i hook the modem up directly to the wall jack,
> and push the voice/data button, i hear a bunch of static. Yes, the lines
> fine now- i am using the modem in my laptop to connect and i hear a normal
> dial tone with a phone. So obviously my modem got screwed. Next question -
> what exactly happened (electronically). I opened it up but couldn't see
What happened electroncally was un-dramatic enough that it didn't cause
damage through any device's packages. A good QC lab could remove the
tops of some of the ICs and see very obvious damage to one or more
chips themselves using a reflected light inspection microscope. More to
question, one or more tiny connections literally melted within one or more
ICs causing opens and/or shorts. In your case, electrically catastrophic,
mechanically, a non-event contained within the device envelope. (Been
> anything. This is the fifth modem that i have blown and i am pissed off,
> especially seeing how this thing cost $350. Next question, how do i go
If this modem cost you $350, one of two things is true:
1) Someone screwed you worse than a direct lightning hit.
2) This modem was purchased so long ago, you got more than your money's
> fixing it? is it a relatively easy problem to fix. It's not under warranty
> so i would have to pay to fix it. How much would USR charge to repair the
> modem (their support is only M-F), could somebody local do it? I'm sure
Cheapest way to fix it is to place it in a special container out on your
the night before garbage collection is due. Then, get yourself a new
modem, such as a USR 005686-03 or better. Shouldn't put you out much more
than $100.00 or so. OBTW, your external modem protected your serial port
everything after it by blowing first. You should consider yourself lucky.
I have an
external for that very reason.
BEFORE installing the new modem, de-install the old modem software.
> is a common problem and anybody that has exprienced this before, please
> me out and give me some advice on what to do next.
I have a Zoom device called a "demon dialer". I have surge protection out
yin-yang, both on the phone lines as well as the mains. If I dare to use it
summer, I'll replace the main chip come winter
[for $75 no less since it's a discontinued item]. Since it was originally a
version, I keep it now for posterity but hardly ever connect it any more.
Bottom line: All telephonic devices vary in their vulnerability to
Surge protection will give you SOME semblance of security,
but ONLY in those cases where you take a hit from a lightning strike
a mile or more away, give or take.
Hope this helps a bit.
In HIS Service,
Tony Cruz (W8OKX - ex WN2OKX, WA2OKX, CT1EGV)
GOD BLESS AMERICA!
You will have to check, with instruments, the components in the
phone interface. Probably either protection fuses, or the hook SSR.
Second, destructive surges must have an incoming and outgoing path through a
damaged appliance; else no damage. So what was that path? The phone line, if
properly installed, already has effective surge protection connected less than
10 feet to earth - if the homeowner has not compromised that connection. But AC
electric typically has no such protection. Destructive surges enter via AC
electric. Since not shunted to earth at the service entrance, an AC electric
line surge seeks ground, destructively, through some appliance. One good path
is via motherboard and modem to phone line ground. Incoming on AC electric.
Outgoing on phone line. Typically, the modem is damaged in the DAA section.
Start there to repair a modem. Easier if you have an oscilloscope to trace
phone line signals. Fuses typically are not damaged by such surges. Check for
Third, surge protection has been well understood and effectively installed
since the 1930s. Plug-in surge protectors routinely violate those proven
principals. Most critical component of a surge protection 'system' is earth
ground. Effective surge protectors discuss this most critical 'system'
component extensively. Those plug-in surge protectors never mention earthing.
Why? Maybe because you would ask some embarrassing questions? A surge
protector is only as effective as its earth ground. A solution begins with a
'whole house' surge protector connected less than 10 feet to central earth
ground. All incoming utilities connect to central earth ground either directly
or through a surge protector. Phone lines, as previously noted, typically have
that 'whole house' protection. Incoming CATV and satellite dish wires also
require that critical, less than ten foot, connection to central earth ground.
Existing plug-in surge protectors provided no protection. Explained is but
one reason why. The surge path through a modem's DAA defines where to located
damaged components. 'Whole house' surge protection has been the proven 'system'
since the 1930s. Residential AC electric 'whole house' protection starts at
about $1 per protected appliance. The most critical component of any effective
surge protection 'system' is central earth ground. Earth ground is fundamental
to defining effective and ineffective surge protectors.
Check all vacuum tubes as well using a good, transconductance tube tester.
>so you're saying the modem was blown through the AC? that doesn't make sense
>or else other components would have been harmed. It had to be through the
>phone lines since the only devices i have ever lost in my house have been
>modems (5 of them)...
I was originally a skeptic until my friend's house suffered a direct
strike. I analysed the damage and posted my results here:
Lightning strike damage report
On a previous occasion another strike caused the following damage, at
the same house:
-- Franc Zabkar
Please remove one 'g' from my address when replying by email.