Replies are only as useful as facts first provided. For example, you mention a line cord. Is that an AC power cord? Phone line? Headset?

If the phone is shorting telephone lines, than the phone is defective. Unreported is what that phone is doing. Reported is that other phones do not work. Do not work when an incoming call should cause a ring? Terminates a dialtone after 20 seconds even when on hook? Eliminates the dialtone immediately?

Anyone can say the phone is probably defective. Nobody (and be honest) can say anything more. But then what are you trying to do? Fix a $10 phone? Or determine if the phone is good enough to create arson?

Thanks a lot for nothing

That was not nothing, with all due respect it was a series of questions soliciting more information about your problem. Many are the same ones I would have asked to get sufficient info to diagnose the problem.

It does sound like the phone may have a problem not related to the battery, but it's hard to be sure.

The OP's post of thanks for nothing is extremely rude. You don't give enough info, someone willing to help asks for details ⦠and you respond rudely? Wow.

I thought it is battery issue.

"Thanks a lot for nothing"

Real Class - maybe just a Senior Moment of self entitlement. lol