🔋💻 ASUS 19V 40W Laptop Charger
 
(19V 2.1A AC Adapter • 40W • 2.5 mm × 0.7 mm Barrel Connector • No Center Pin)

This compact AC adapter delivers 40W of regulated DC power to ASUS laptops using the small 2.5 mm × 0.7 mm barrel connector. It was the standard supply for ASUS’s Eee PC netbooks and early ultraportables, designed for maximum portability and efficiency.
 
🔧 Charger Form
Input: 100–240V AC, 50/60Hz
Output: 19V DC, 2.1A (40W)
Connector: 2.5 mm outer / 0.7 mm inner barrel, no center pin
Lightweight, travel‑friendly brick design
Often labeled as ADP‑40PH, ADP‑40TH, or equivalent
 
🖥️ Compatible Devices
🧳 Eee PC 1000‑Series
1001HA, 1001P, 1001PX, 1001PXD
1005, 1005H, 1005HA (A/B/E variants), 1005PR
1008HA
1011PX, 1015PE, 1015BX, 1018P
🖥️ Eee PC 1100‑/1200‑Series
1101HA, 1104HA, 1106HA
1201N, 1201PN, 1201HA
🧩 Eee PC 1215/1225 Series
1215B, 1215N
1225B
💻 X‑Series / Netbooks
X101, X101CH, X101H
🔄 Other Small ASUS Systems
R011PX, R051PX
UL20A ultraportable
UX30 ultrathin
Select Chromebook C202SA configs
 
✅ Common Uses
🔌 Powering ASUS Eee PC netbooks and early ultrathins
🧩 Replacing lost or damaged OEM chargers
🏢 Standardizing spares for school or office netbook fleets
🎒 Keeping as a lightweight travel adapter
🧪 Testing legacy ASUS systems with a known‑good 40W supply
 
🧠 Signal Format
⚡ Input: Universal AC (100–240V)
🔋 Output: Regulated 19V DC, 40W max
🔌 No center pin — relies on barrel contact only
🔁 Backward compatible with some 30–33W netbooks (safe, charges faster)
 
⚠️ Things to Watch Out For
📉 Not suitable for ZenBooks, VivoBooks, or gaming laptops (require 45W–230W)
🔌 Connector must match — not interchangeable with ASUS’s 4.0 mm × 1.35 mm or 5.5 mm × 2.5 mm barrels
🧯 Avoid third‑party clones with poor contact — may cause intermittent charging
🌀 Excess heat or frayed cables can cause power dropouts
🧪 Always confirm connector type and wattage before swapping adapters
 
🛠️ Quick Tips for Beginners
🧭 Check underside of laptop or original charger for voltage and connector size
🔌 Use only with laptops rated for 40W and 2.5 mm × 0.7 mm input
🧪 If laptop reports “adapter not recognized,” inspect barrel contact and cable integrity
🧯 Label adapters clearly to avoid mix‑ups with other ASUS chargers
🧵 Keep one at desk and one in travel bag for convenience