[iwaztomack]

I have a 42 year old apple //e that had been in an uninsulated attic in Boston for 30+ years. It booted fine and all the 5 1/4" floppies worked. I know that C64s need the caps replaced and the org external power supplies can catch fire. I'd be really surprised if 1990's pcs failed. There was a period of transition to non-lead solder where many pcbs from that era suffered shorts from whiskering but everything else should be fine. Electromigration tolerances in the 90's cpu families was even more strict than today.

[RF_Savage]

1990's PC's have Varta bios batteries soldered on that leak and destroy the motherboard. Or they have Dallas real time clocks with dead batteries.

[iwaztomack]

I'm staring at a PC-AT mobo from 1988 with an AMD-branded 286 chip that also says Copyright Intel (lol), and the battery has leaked a white film.

[tonyarkles]

It’s kind of funny to me how the different manufacturing and supply chain factors have caused these reliability “sweet spots” and “death spots”.

Like you mention, the leaded to lead-free solder transition was one of them. I agree about 90s PCs quite likely being reliable. But then… 1999 to 2007 we had the capacitor plague: https://en.m.wikipedia.org/wiki/Capacitor_plague

And around 2002 there was the Great Fujitsu Hard Drive Recall: https://www.theregister.com/2002/10/31/fujitsu_faces_lawsuit... If I’m remembering that one, they changed out a flame retardant additive in their chip packaging? Something like that? Those drives were approaching a 100% field failure rate and you could mail them back to Fujitsu and get a cheque for $100.

[guenthert]

I recently turned on a PC some ten years old which was in storage for five years. First time it turned on, but had difficulties booting due to the M.2 SSD from Intel being corrupt. Second time, it failed to turn on (but some LEDs on the MB indicated that there was still some power), fans not spinning. Third time, it did start again, but the fans at full speed and fan control not working anymore. It seems the lubricant of the fan's bearing dried up and made them hard to spin to the point that the in-rush current exceeded the capacity of the fan-control chip.

Fortunately, those beige^black boxes hold no sentimental value whatsoever and will be replaced with something better at a convenient time. Before turning on something more rare, I'd inspect the MB visually for corrosion, bloated caps and test the fans and disk drives externally.

[nrdvana]

My understanding is that every electrolytic cap will eventually dry out. The capacitance drifts as this happens, so the quality of the cap and the sensitivity of the circuit to incorrect capacitance will greatly affect how long it takes for the device to fail. The late 90s was also when a large quantity of low-quality electrolytic caps were manufactured.