Classic wont turn on again hahah

Hey guys, I've got a classic for 2 mounths I think, I bought it from my friend
then it worked 100% for days, the first problem was fixed with an autoloader
some days after, it stopped to turn on, I tried for days, and finally had sucess
recently I bought a new display, and when I tried to turn the phone on, neither led nor anything lit, same as last time
I tested the battery with a voltmeter, and it is passing the voltages correctly
I washed the motherboard of the cell phone with isopropyl alcohol, but without success
I already reviewed the fittings, everything is ok
when I disconnect battery, a yellow led turn on for about 30s
the battery cycle is at 602, I dont think it's bad because the phone was bought in 2016
according to my friend, the reason he sold it was because he did not adapt to keyboard, and he knew I love bb keyboard phones...
What else can I do?

sorry for bad english hehe

Buy a new phone

Sent from my Secure BlackBerry Classic

Sounds like you replaced and verified the external components. Not sure if trialing the phone on AC would eliminate the battery from the process?

Anything loose / fried on the motherboard that you can see? Odd solder lugs or metal flakes making contact?

If not I would replace the battery then the MB.

 Classic SQC100-2 | 10.3.2.2813

I already wiped the motherboard.
I believe that it is a problem in the battery, it is bad to know, because where I live does not have blackberrys
and the batteries and spare parts are too expensive

There's 150 Dollars
Here's 900 Reais
it's not the best thing to do but I'll try some more, if it doesnt wake up I can get a new one