Motorola wireless phone losing base link

[Joerg]

Hello Folks,

It happened for the second time: After brief power outages a digital
cordless phone (Motorola MD450 series) has lost its base station
contact. When it does that it will display "out of range" even while
cradled on its base.

Any idea what might cause this?

We do not keep batteries in the base but according to the info that came
with it these are only meant to keep the base talking during a power
outage. They certainly do not keep up the station ID since I can program
it, unplug it, carry it to another location and upon plugging it in the
phone will work fine. It seems as if this phone or its base do not like
brief power outages.

Regards, Joerg

 

[Ken Taylor]

Hello Folks,

It happened for the second time: After brief power outages a digital
cordless phone (Motorola MD450 series) has lost its base station
contact. When it does that it will display "out of range" even while
cradled on its base.

Any idea what might cause this?

We do not keep batteries in the base but according to the info that came
with it these are only meant to keep the base talking during a power
outage. They certainly do not keep up the station ID since I can program
it, unplug it, carry it to another location and upon plugging it in the
phone will work fine. It seems as if this phone or its base do not like
brief power outages.

Regards, Joerg

Sounds like it does a dirty reset. What do you do to fix it?

Cheers.

Ken

 

[Joerg]

Hello Ken,

Sounds like it does a dirty reset. What do you do to fix it?

Could be. Although all the programmable settings are in the handset and
that doesn't need to do a reset since it's buffered by its battery.
Maybe there is something in the base that gets confused. That would be a
real disappointment though, considering that it is from Motorola.

Last time I tried to fix a reset I found that it was all under a huge
blob of tar, including many of the discretes.

Regards, Joerg

 

[martin griffith]

Hello Ken,


Could be. Although all the programmable settings are in the handset and
that doesn't need to do a reset since it's buffered by its battery.
Maybe there is something in the base that gets confused. That would be a
real disappointment though, considering that it is from Motorola.

Last time I tried to fix a reset I found that it was all under a huge
blob of tar, including many of the discretes.

Regards, Joerg

ah, the good old days
http://www.batnet.com/mfwright/HT220.html


martin

 

[GrandPaBobby]

I had a Panasonic which did the same thing. I called their tech support
and was given a procedure to fix the problem. The "fix" involves
removing the battery from the handset, unplugging BOTH the phone line
and power source from the base. You then wait about two minutes, and
reconnect things in a very specific order.

This does the job! I can never recall the order of reconnections but
wrote it down in the manual. Chances are this will fix your Motorola as
well as I suspect most of these phones share some circuitry and/or
chips.

Hope this helps.
Robert

 

[Joerg]

Hello Robert,

I had a Panasonic which did the same thing. I called their tech support
and was given a procedure to fix the problem. The "fix" involves
removing the battery from the handset, unplugging BOTH the phone line
and power source from the base. You then wait about two minutes, and
reconnect things in a very specific order.

This is also what I tried and basically how I was able to re-sync at
all. But it only lasted until the next power glitch.

Somehow this all sounds like poor engineering. Kids learn all that
high-level math at college but I bet most of them don't have the
foggiest idea what a watchdog timer is, let alone using one to recover
from hanging due to a dirty reset or brown-out.

In fact, many times when I looked at code I found the watchdog timer was
disabled. That's like not having one.

Regards, Joerg