Toshiba laptop won't run while charging

[Elaine]

I recently had to replace a faulty charger, I purchased the exact same one as the original from a reputable store & even though it charged the battery fully my laptop won't run while charging unless it's at a 100% or if I run it on the battery.
It boots up fine & I can connect to the internet but I'm unable to browse the net, the timer signal just goes round & round (sorry I don't know all the technical jargon).
I returned charger to store & they replaced it but the problem is still there.
Can anyone PLEASE help? Thanks

 

[Tmagic650]

Does the laptop run with only the AC adapter with the battery removed? If it does, the battery may be bad

 

[Elaine]

I've tried removing the battery & just using AC power but that doesn't work, also I bought a new battery a few weeks ago to see if this would resolve the problem, unfortunately it didn't. The only way I can use my laptop is through the battery or if it's plugged in & at 100% charged, if I try to use it if plugged in & it's not fully charged then the same problem occurs.
I'd be so grateful if anyone can shed any light on this as I'm at the end of my tether with it. Many thanks!

 

[Tmagic650]

There is probably a circuit failure in the battery charging circuit on the laptop's motherboard. This means a new motherboard is needed