MacBook Pro A1278 13" mid 2012 2.5Ghz i5 - issue

Hi,

My MacBook Pro A1278 model mid-2012 I5 is showing spots or lines on screens. Sometimes the words and letters get juggled up. Sometimes the top menu bar is not rendered.. these used to happen randomly at the beginning, but now it's always happening, right from the login screen.

When I disconnect battery and work directly with the adapter connected, I don't see the issue. So, thinking that it's an issue with the old battery, I replaced it, but the issue persists when battery is connected.

Any insights would be helpful.

Warm Regards

Madhu