FAQ
TL;DR: Power stored 90s gear for 1 hour/month; “swithing them on for one our in a month will be fine.” In 33–36°C storage, this prevents disuse failures. [Elektroda, Olkus, post #21366881]
Why it matters: Owners of CRT TVs, consoles, PS2s, and other 90s gear in warm climates can prevent electrolytic-capacitor start‑up failures with simple keep‑alive routines.
Quick Facts
- Typical aluminum electrolytic ratings: 85°C or 105°C; ~35°C storage sits well below these categories [Elektroda, Olkus, post #21366681]
- Keep‑alive practice: energize for about 1 hour per month during storage [Elektroda, Olkus, post #21366881]
- Acceptable minimum if busy: 1 hour once per year also works [Elektroda, Olkus, post #21368897]
- After very long downtime, ramp voltage with a Variac/autotransformer to re‑form gently [Elektroda, mariostan, post #21262774]
- Off‑circuit re‑form: use ~1.2 kΩ/2 W in series; leakage often drops to 5–10 mA after ~12 hours [Elektroda, dipol, post #21421996]
What’s the safest interval to energize 1990s devices at 33–36°C?
Switch them on about once per month for roughly one hour. This preserves the oxide layer and avoids high leakage at start‑up. The recommendation comes from hands‑on experience with vintage radios and similar gear. That cadence is reasonable for CRT TVs, consoles, and power supplies. It fits warm storage without overworking aging parts. [Elektroda, Olkus, post #21366881]
Is once a year for one hour enough in warm storage?
Yes. The same practitioner confirms an annual one‑hour power‑up is acceptable. “I think that will be OK.” If you want extra margin, do it twice a year. Monthly remains the safer maintenance interval for high‑value gear. [Elektroda, Olkus, post #21368897]
Do 33–36°C conditions harm 85/105°C‑rated electrolytics?
No. 33–36°C is well below the common 85°C or 105°C ratings. A contributor notes capacitors from the 1990s will not be broken by ~35°C storage without voltage. Check individual datasheets when available for storage guidance. Temperature margin reduces chemical aging rate significantly. [Elektroda, Olkus, post #21366681]
Does it have to be exactly 60 minutes every time?
No. Duration is flexible. A few minutes to an hour at idle is fine. The key is periodic energizing, not precision timing. Let the device idle; avoid heavy load if you only intend preservation. [Elektroda, zdzisiek1979, post #21261930]
How do I power up long‑idle gear safely (CRT TVs, receivers)?
Use a gentle ramp to re‑form the capacitors. A Variac/autotransformer works well.
- Disconnect heavy loads and connect through a Variac or autotransformer.
- Increase AC voltage gradually while watching for heat, smell, or noise.
- Let it run at full voltage briefly once stable, then proceed to normal use.
This approach has kept even a 1957 receiver’s electrolytics working. [Elektroda, mariostan, post #21262774]
How can I re‑form individual electrolytic capacitors off‑circuit?
Use a series resistor at the rated DC voltage. One method uses about 1.2 kΩ/2 W in series to limit current. “After 1/2 day the current dropped to 5/10 mA.” The user then reused large capacitors successfully in 13.8 V and 25 V supplies. Maintain polarity and monitor temperature during forming. [Elektroda, dipol, post #21421996]
Which devices are most at risk—CRTs, consoles, or SMPS power supplies?
Expect switch‑mode power supplies to be the weak link. One experienced repairer estimates 80–90% of equipment damage comes from bad capacitors, especially in SMPS designs. Cheap parts near hot heatsinks accelerate failure. Replace suspect caps or preemptively re‑cap critical supplies. [Elektroda, dipol, post #21421996]
Should I power under load, or is idling enough for preservation?
Idling is enough for preservation cycles. Switch the unit on and let it idle during the keep‑alive period. This keeps leakage in check and re‑forms the dielectric without heavy stress. You can vary duration between a few minutes and an hour. [Elektroda, zdzisiek1979, post #21261930]
Can I skip monthly power‑ups if everything seems fine?
You can. A contributor runs valve radios that sometimes sit a year without issue. They report that capacitors do not fail from such pauses. Still, monthly power‑ups provide additional confidence for expensive or mission‑critical gear. Choose the cadence that matches your risk tolerance. [Elektroda, Olkus, post #21366881]
Do 1990s electrolytics generally still hold up today?
Yes. One owner reports a 1978 radio‑magnetophone still working on original electrolytics. That indicates decades‑old parts can remain serviceable. 1990s capacitors are not excessive age by comparison. Inspect for bulging, leaks, or rising ESR before heavy use. [Elektroda, buszyl33, post #21365656]
Should I check capacitor datasheets for storage and re‑forming info?
Yes. Manufacturers list temperature categories, storage limits, and operating guidance in datasheets. The forum advises reviewing datasheets when possible for your exact parts. This helps you align intervals and temperatures with stated limits. Keep a note of each brand and series. [Elektroda, Olkus, post #21366681]
Any tips for high‑humidity, tropical storage?
Prioritize build quality and protection in humid climates. One engineer notes boards on marine gear were conformal‑coated and climate‑chamber tested. That approach limits corrosion and leakage paths. Store gear dry, and consider conformal coating or desiccants if you service boards. [Elektroda, dipol, post #21421996]
Should I re‑form NOS capacitors before installing them?
Yes. Re‑form decades‑old NOS electrolytics before first use to avoid surprises. This restores the oxide and reduces leakage current. A simple bench re‑form prevents in‑circuit stress and nuisance failures. It takes little time and improves reliability. [Elektroda, buszyl33, post #21365656]
