The capacitor that Apple soldered incorrectly at the factory

Original Article ↗ Hacker News Discussion ↗

Recalls, Lifespan, and Manufacturer Responsibility

  • Debate over whether companies should recall decades‑old defective products (e.g., early‑90s Macs, pre‑1990 Trinitron CRTs).
  • One side: if a product was defective from day one or becomes a fire hazard, age should not excuse the maker from fixing it.
  • Other side: 20+ years is beyond the “expected” life for many electronics; parts may be unavailable and repairs impractical.
  • Underlying tension between environmental concerns (don’t trash fixable gear) and economic reality (modern devices are cheap, labor is not).

Right to Repair and Serialized Components

  • Apple’s part‑pairing/serialization is criticized for making independent repair harder, especially board‑level fixes and parts stocking.
  • Defenders argue serialization helps suppress stolen‑parts markets and enables verified “genuine” repairs.
  • Critics say Apple’s policies are more about monopolizing repair revenue than theft reduction, and that “genuine parts available from Apple” is undermined by strict logistics and authorization rules.

Capacitors, Polarity, and Failure

  • Thread clarifies polarized vs unpolarized capacitors, why electrolytics have polarity, and what happens when reversed (oxide layer dissolves, shorts, heat, gas pressure, potential venting).
  • Typical lifetimes for consumer electrolytics ~6–10 years at modest temperatures; the “capacitor plague” era saw failures in ~2 years.
  • Many modern failures (TVs, routers, LED bulbs) blamed on dried‑out or overheated capacitors, especially in cramped, hot enclosures.
  • Some note you can often extend life by recapping, though diagnosis and board fragility make it nontrivial.

Manufacturing and Design Errors Beyond Apple

  • Multiple examples from Commodore, Sinclair/Amstrad ZX Spectrum, Atari, and others of reversed capacitors, transistors, or pointless parts (e.g., capacitor tied to ground on both ends).
  • Discussion stresses this LC‑III issue is likely a schematic/library error, not factory “soldering wrong”: production followed the provided design.

Product Quality, Obsolescence, and Consumer Choices

  • Strong disagreement whether modern electronics are genuinely worse or just optimized differently:
    • Some report TVs and appliances lasting 10–15+ years, others see failures just past warranty.
    • Engineers emphasize “value engineering”: shaving BOM cost because consumers overwhelmingly buy the cheapest, even if it shortens lifespan.
  • Long side‑thread on LED bulbs: many fail early due to hot, cheap power electronics; some see this as de facto planned obsolescence, others as an unavoidable tradeoff at current price points and form factors.
  • Several argue that it’s hard for buyers to distinguish real quality from mere branding, leading to a “race to the bottom”.

Mac Serial Ports and the -5V Rail

  • The mis‑oriented capacitor sits on the –5 V rail, mainly used to make the RS‑422 serial ports also act like RS‑232 (e.g., connect directly to modems).
  • Measurement in the article showed the backward cap dragging the rail to about –2.4 V; still usually enough for RS‑232 receivers and RS‑422 specs, explaining why machines “just worked” despite the error.
  • Some modern hobbyists add proper negative rails (via charge pumps or ATX supplies) when refurbishing these Macs.

Vintage Mac Anecdotes and Maintenance

  • Multiple users reminisce about LC/Performa/Quadra era Macs, including networking games over serial and running late‑90s software on underpowered 68k machines.
  • Advice for restorers: remove leaking clock batteries, recap aging boards, and be aware that some models used tantalums (less prone to leakage) while others used electrolytics that can damage PCBs over time.