Chosen Solution
I have the set of 5 Panasonic cordless phone. The problem I face is very strange. On some of the battery charging points, the phone shows charging on display but actually it’s not charging. What can be wrong? The battery charging point is Panasonic PNLC1050. It looks like that some of the battery charging points are not able to charge the phone (if charge is low), though the phone says charging on display. The same phone gets charged on other battery points. For me, the phones charge only on 2 of the 5 battery charging points I have. Infact the strange thing I find is that if the charge in phone is low, then it doesn’t charge at all, though the phone screen says charging. After 36 hours or so, the phone loses all charge even when it was on faulty battery charging points all along. What can I do to solve the problem? Why would a battery charging point not charge my Panasonic phone though it shows its charging?
There is a diode on the circuit board, if this is faulty the phone will show to be charging- but the charger will actually drain the hand-set batteries. I de-soldered this off the board and re-placed with a small diode off a defunkt circuit board that I happened to have, any small value diode should fix this. The old diode must be removed. Mine now works fine. -David
I don’t know enough to replace diodes or repair my phone or base. I have the same symptoms of the original poster. Is it more likely the problem is with the handset or base? I’ll just replace the culprit. Thanks
Have a slightly different problem. 1 out of 4 handset is forever charging even though battery is full. I can put a known full battery (shows full in other handsets) into this one and it will show 1 bar. If the handset charging circuit think battery is not full. All of this without the charging station. The charging station is fine as I can put other good handset in there and battery charing behavior is correct (shows charge complete when full) So obviously if the handset thinks a full battery is not full, then its always charging and generating heat like what I am seeing. Going to probe the circuit board (pic below) for voltage readings. Looks like there are diode on the battery side also. Wondering if others have had this problem. I have 4 handsets and using a known good fully charged battery, I get 2 handsets showing 1/3 bars, 1 showing 2/3 bars, and only 1 handset showing 3/3 bars. Dug a bit deeper into the schematic (didn’t find exact but perhaps close) Battery voltage is fed to the IC (likely pin 58 of basedband IC SC14430). IC reads voltage and make decision to trigger the external charge circuit (transistors + diode system). 3 Voltage islands on the handset board (3.3V, 2.5V, 1.8V) identical readings between good handset and bad one.
On the good handset, had the handset opened up with alligator clips on battery post for 2xAAA power supply. The alligator clips accidentally touched the 2 charge terminals as its easy to do with the back cover off. Battery and charger terminals next to each other are reverse polarity and the good handset also shows 1/3 bar on full battery after touching. There was no spark or noise. Something must be really easy to damage with such low voltage and current.
I am having the same issue. You a very technical person. Can you state in layman’s terms how to fix?
hi, i have a somewhat similar problem with my panasonic handset. my handset is 110v and i live in a country with 220v. i usually just get an adapter 220v to 5v and splice them up. this time i accidentally switched the wires while splicing. when i put the phone on the dock, it somewhat reversed the phone. meaning when i remove it from the dock. it says that its charging and i cant use it. and when i put it on the dock it thinks that it is out of the dock and i can use the phone. i tried the dock again with another phone, and it did the same. it somehow reversed the phone. after that i doubled checked my splice and found out the i reversed the wires. is there a way to fix this? not sure if the polarity is the issue. for now i cant use the phone. thanks in advance Update (08/02/2020)
There are 3 possibilities - bad batteries, bad charging base, bad contacts. It’s clear that bad charging base (defective diode) has happened to a number of people and is probably the main reason people come here (after all, you will have replaced the batteries before you get to this topic). Why not just close this topic - it’s been solved!
Remove the single screw from the base unit. Pry the base open. Inside there is a circuit board, on it is a small black component (a magnifying glass will help) there is a small diode symbol on the board next to it. Using a soldering iron, melt the solder holding the diode and remove it from the board. Get a new diode (ebay?) and solder it in place of the old one ( it must go the correct way round). It doesn’t have to look pretty, so long as the connections are ok. - That is it.
Type Panasonic KX-TGB110 I have a problem The phone is not working even after changing the batteries with another one it always shows the same message as attached
The question has not been fully answered. People who want a thread closed ought to have their own circuits examined. In the case of my phone, the problem is neither the base nor the batteries nor the contacts, it’s the charging circuit in the handset. I know this because I cleaned the contacts on the handset, transferred its batteries to a different phone, and put that phone into the same base. Phone #2 charged fine in that base.
