u/Low_Opening_2175

So my laptop is kinda old, its a Thinkpad. Once before my laptop completely shut off and wouldn't turn on unless I had it plugged in, we replaced the battery and it worked fine again. (This was last year) Now yesterday, when I opened it the power button was blinking but no matter how long i pressed the button it wouldn't turn on. I plugged it in and it turned on, I unplugged it and it stayed on and worked fine. I honestly don't know whats wrong with it; is it the battery or what? Buying a new laptop is the option I'm trying not to go with because its not my money thats going to be spent. Help is GREATLY appreciated!!