First start of an IBM APTIVA 486DX2-66 (2144-914) after at least 20 years in storage

First start of an IBM APTIVA 486DX2-66 (2144-914) after at least 20 years in storage. Will the first power-on of this old IBM APTIVA 486DX2-66 go smooth after at least 20 years in storage or will it result in a several kilogram heap of burnt out electronics? After some cleaning up and inspection of the motherboard, capacitors and the CMOS battery I decide it´s time to power this old beauty of a retro computer up. I really look forward to play some good old DOS-games :)