Schematic for cordless phone & advice on repairing
Steve Ngoh
Hi,
Recently when I tried to dial out using the portable unit of my
cordless phone, I found out that the base unit does not goes off hook and
when there's an incoming call the ringer on the portable unit does not
work. I suspected that the transmitter of my portable unit or the receiver
of the base unit is at fault. So could anyone out there give me some advice
on troubleshooting the faulty circuit or email me the schematic diagram for
Panasonic KX-T3911BH cordless phone.
Thanks in advance.
Paul Grohe
On 22 Dec 1996 13:50:45 GMT,
in the newsgroup sci.electronics.repair,
"Steve Ngoh" <man...@singnet.com.sg>
from F.A.M.E thoughtfully posted:
Sounds like the "classic" Panasonic portable problem.
The base and handset somehow loose track of the security code and
/or operating channels. This is (unfortunately) extremely common
(if I only had a dime....).
This commonly happens after extended power failures or unplugging
and moving the base, with the handset removed from the base.
Letting the handset batteries completely discharge can also cause
this.
It needs a "forced" reset.
Fix: (assuming a "good", charged battery)
1. *Unplug* the base power jack.
2. Turn the handset "ringer" switch off and unplug the battery
from the handset.
3. Wait 20 minutes. While you are waiting, it is a good idea to
clean the charging contacts with a clean cloth.
4. Plug the base unit power jack back in.
5. Plug the battery back into the handset and turn the handset
"ringer" switch back on.
6. Place the handset back in the cradle. Verify that the
"charging" indicator comes on.
7. *WITH THE HANDSET STILL IN THE CRADLE*, press the "page" or
"intercom" button on the base. "Nothing" should happen (the jury
is still out as to how necessary this step is, but it seems to
help some models, like the ones with the LCD display)
8. Then remove the handset and press the page button. Hopefully
it should have come back to life.
9. If not, try 6 thru 8 again. Or repeat the whole process,
waiting longer than an hour in step #3.
Once the "page" function has been verified, then try the "talk"
button.
Other things to look for are dead batteries, dirty/bent charging
contacts, loose/broken antenna connections and worn/dirty "talk"
buttons.
Good Luck!
Cheers,
Paul Grohe
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