Is it possible my SMC chip is faulty?

So, I actually had liquid spillage on my MacBook Pro.

I sent it for repairs, and the diagnosis and repair was to simply replace the top case, because according to them, the LogicBoard was working fine.

However, when it was returned, I started having problems.

When I got it back, first the shut down prompt would pop up randomly and frequently, and if I clicked 'Cancel', it would shut off. Then sometimes, it would turn on, get to the grey loading circle, then shut off abruptly once it got to the blue screen.

My battery is also now showing 'Service Battery', even though prior to this, it was functioning absolutely fine, and coconutBattery shows that it can still hold a charge.

I have reset the PRAM and SMC, repaired disk permissions and done all maintenance. I have also tried switching to a different user account.

The issue still persists. I have returned it twice to the repair center now (although because I requested it, they removed my hard disk drive and transferred it to another computer so I can use it) and both times they just replaced the top case again.

So, is it possible that the diagnosis wasn't done properly, and there is something wrong with the SMC chip?

Thanks!