Does it allow the amp to run cooler of I replace heatsink compound?

[chipper]

I recently bought a nice mint punch 360a2 I broke the warranty seals (doesn't matter to me since I don't plan on selling it) I just wanted check
It out inside so I removed the whole board from the heatsink and I notice the original thermal compound was dried up. I cleaned it and put in Dow Corning 340 thermal compound. So is it going to run a lot more 'hotter' than before?

 

[seankane]

The heat sink will seem hotter but this is not bad because that means the MESHA board is tranfering heat to the sink from the components more quickly and than before. Dried up compound will cause the amp to be hotter internally and not transfer the heat to the sink because of the voids and such. Heat is a killer on internal components.

The heat compound lets the MESHA board transfer heat to the sink because obviously the MESHA board cannot make an "air tight" seal to the sink leaving voids and such creating more heat on the internal components mounted to the MESHA board.

 

[chipper]

Thanks for the reply, so this means it's going to run much more hotter now, right? And fets and the rest of the components will be cooler while the sink is hot?

 

[seankane]

I cant say that for the rest of the components, the components mounted to the MESHA board will definantely run cooler with new compound, and this may appear to make the sink hotter due to the quicker and more efficient heat transfer to the sink.

 

[Wavebourn]

Thanks for the reply, so this means it's going to run much more hotter now, right? And fets and the rest of the components will be cooler while the sink is hot?

It depends on difference in thermal resistances of an old paste and the new paste. The thinner is the layer, and the bigger is the area, the lower is the thermal resistance, if properties of pastes are equal. That means the lower temperature difference between the cooled device and the heatsink.