FAQ
TL;DR: Your laptop’s adapter (19.5 V/3.33 A ≈ 65 W) can cause a mild tingle via EMI leakage; “This is the design of the power supply.” Grounding (PE) or a 3‑prong adapter reduces it. [Elektroda, Krzysztof Kamienski, #17585177]
Why it matters: This FAQ helps HP Pavilion and similar laptop users diagnose tingling shocks, decide if the PSU or socket is at fault, and fix it safely.
Quick Facts
- Adapter label: Input 100–240 V, 50–60 Hz; Output 19.5 V, 3.33 A (~65 W). [Elektroda, Problematyczna, post #17585015]
- Two‑prong/Class II bricks lack PE; EMI capacitors can make metal or USB “kick” slightly. [Elektroda, Krzysztof Kamienski, #17585150]
- A wall socket’s ground pin must be wired to PE; the pin alone is useless. [Elektroda, Piotr160292, post #17585172]
- Touch‑current safety limits are approx. 0.25–0.5 mA under IEC 62368‑1. [IEC 62368-1, 2018]
- Model discussed: HP Pavilion 15‑n070sw; palmrest may feel metallic. [Elektroda, Problematyczna, post #17585124]
Why do I feel a shock when touching my laptop’s case?
Your adapter uses an EMI filter with Y capacitors. They reference the DC ground to mains through capacitance. That creates a tiny AC touch current and a tingle. “This is the design of the power supply.” It appears when plugged in, not on battery. [Elektroda, Krzysztof Kamienski, #17585177]
Is the problem in the laptop or the power supply?
It is the adapter’s design, not the laptop. Class II bricks lack PE and can “kick” slightly. USB shields or metal trim may feel it first. The sensation usually disappears on battery power. [Elektroda, Krzysztof Kamienski, #17585150]
What does PE/ground do in this situation?
PE is the protective earth conductor in your installation. It shunts leakage to earth, stabilizing the laptop’s reference. A socket’s ground pin must be wired to PE. A floating pin gives no protection or benefit. [Elektroda, Piotr160292, post #17585172]
Can a socket look grounded but still not be?
Yes. A socket can show a pin yet lack PE. The yellow‑green conductor may be missing or disconnected. Use another verified grounded outlet to compare behavior. [Elektroda, Piotr160292, post #17585172]
How much voltage or current could be on the case?
You feel a small touch current limited by safety standards. Typical limits are about 0.25–0.5 mA for ITE. The sensation can occur even though current remains very low. [IEC 62368-1, 2018]
Could the USB port be the part that “kicks”?
Yes. The USB shield ties to the laptop’s DC ground. EMI capacitors reference that point to mains via capacitance. “If not the frame, the USB socket will ‘kick’.” [Elektroda, Krzysztof Kamienski, #17585150]
How do I quickly test whether the PSU or the outlet is at fault?
Use this quick isolation test.
- Run on battery only. Confirm the tingle disappears.
- Move to a known grounded outlet. Recheck the tingle.
- Inspect the adapter plug. Look for a PE contact.
Lack of PE on the plug or outlet implicates grounding. [Elektroda, Krzysztof Kamienski, #17585167]
Is this dangerous, or just annoying?
For compliant adapters, touch current stays within IEC limits. It is usually annoying, not hazardous, under normal conditions. Ensure a proper PE path and stop if shocks feel strong. [IEC 62368-1, 2018]
What model and materials are relevant here?
The reported system is HP Pavilion 15‑n070sw. The palmrest ring may feel metallic to the touch. Outer shells can still be plastic despite metallic feel. [Elektroda, Problematyczna, post #17585124]
Why does it happen only when on the power supply?
The effect requires the adapter connected to mains. On battery, the laptop floats without AC leakage path. The OP noted tingling only while on the power supply. [Elektroda, Problematyczna, post #17585015]
How much power is this HP adapter?
Its label shows 19.5 V at 3.33 A. That equals about 65 W output power. Power rating does not directly predict tingling intensity. [Elektroda, Problematyczna, post #17585015]
What can I do to reduce or eliminate the tingling?
Use a properly grounded outlet and adapter with PE. Where PE is absent, Class II bricks may tingle by design. Replacing the brick can help if it feels abnormal. [Elektroda, Krzysztof Kamienski, #17585150]
Could the outlet’s PE be present but ineffective?
Yes. A visible pin without a wired PE is ineffective. The pin alone does not provide protective grounding. Have an electrician verify the PE continuity if unsure. [Elektroda, Piotr160292, post #17585172]
Should I send the laptop or the PSU for service?
Service the adapter first if shocks are frequent or stronger. The described tingling is consistent with adapter design. “This is the design of the power supply.” [Elektroda, Krzysztof Kamienski, #17585177]
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