One of the best things you can do for heat dissipation in vintage computers and consoles is replace the 7805 voltage regulator with a modern switch mode replacement. Here’s why that helps and where to get one.
A modern 7805 switch mode replacement regulator runs cooler than the original 7805. This reduces the need for heat dissipation and helps other components, such as capacitors, last longer.
Modern 7805 switching replacement
Switch mode parts are more complex than traditional linear parts like the venerable 7805. That means they cost more, but they run much cooler.
There are numerous switch mode 7805 replacements that have exactly the same pinout and a very similar profile to the 7805, so they fit right in where the 7805 used to live. The only difference is they stand vertically, so make sure you check vertical clearance. If you need to bend it horizontally for it to clear, you may need to solder extensions onto the pins so you’ll have something to bend.
Unlike the 7805, there’s no universal name for the replacement parts. In the United States, I find the PSU2-5 most readily available. In other parts of the world, you may have an easier time locating a TSR 1-2450 or OKI-78SR-5. While these parts differ in outward appearance, they are all compatible and all have the same pinout as a 7805. Just get the one that’s cheapest in your country and enjoy your slightly modernized vintage machine.
Benefits of using something newer than a 7805
In some systems, the 7805 is the hottest-running part, so replacing it with something that runs so cool it doesn’t even need a heat sink is beneficial. The money you save by not having to replace capacitors again makes them worth it, not to mention the time required. While a traditional 7805 costs around $1, a switch-mode replacement costs $5-$6. Most 80s and 90s home computers and game consoles had a 7805 in them somewhere. So whether you have an Atari 2600 or an SNES or anything in between, all of them benefit from this upgrade.
But besides the caps, most of these systems have chips in them that aren’t being made anymore. Those chips will last longer if the 7805 isn’t radiating them with heat. That’s beneficial too, especially since many of these chips are in short supply and aren’t readily available anymore outside of Ali Express, which has its own issues.