Too bad I downsized ten years ago, otherwise I would conduct some measurements. But yes, replacing old parts for new and better parts surely will help. I'll have to check the System 1 at our computer club, though I believe it doesn't suffer from the same instant overheating issue as the one I used to own (2008-2010), the one a friend of mine used to own (same time period) and the one Bamse is describing.
In a discussion panel from 2009, Lars Jarhamn from Bergsala - who had made themselves a name by importing Nintendo Game & Watch - described how they acquired the distribution of Vectrex and Intellivision in the second part of 1983. While the Intellivision sold very well, they found it have problems with overheating and possibly even "catching fire". They visited the factory in Hong Kong, run by a "rude American" called Clark who didn't want to take responsibility for any faults. Bergsala claimed the motherboards were installed upside down and that would cause overheating, but this Clark guy said he didn't know the difference between upside or downside. Eventually the Intellivision sales went down, while Bergsala were waiting for Nintendo to export the Famicom in a PAL version. Obviously it didn't happen, but they got to release the NES a few years later.