PS4 overheating (RLOD) after cleaning it out

So today I was servicing my brother’s PS4. And when I got to the motherboard, I was going to clean out the thermal paste but before I did that I checked if I had any and it turns out I didn’t. So I reassembled it fully but when I connected it to turn on it would give me a red light and won’t turn. I’m just wondering if it’s the thermal paste that needs to be replaced because no components were harmed during disassembly. Please I need answers

Yes, every time you open the system and have to break the bond between the thermal paste you need to replace it. Also, make sure you put the apu clamp back on correctly

Thank you so much for this information. I was honestly scared that I busted my brother’s console and was going to have to buy him a new one