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Title Goes Here
Something goes here, but I don't know what
Title Goes Here
Something goes here, but I don't know what
Does the schematic protect your device?
When you look for a schematic, ensure it includes these six essential sections:
Based on technical documentation, F4901 refers to a specific resettable fuse (Polyfuse/PTC) commonly found on laptop motherboards manufactured by Wistron, such as those in Dell and Lenovo laptops. Component Summary: F4901 Resettable Fuse
The "1.1A 24V" label denotes the electrical rating of this protection component.
Part Type: Polyfuse / PTC (Positive Temperature Coefficient) Resettable Fuse. Operating Voltage ( Vmaxcap V sub m a x end-sub ): 24V. Holding Current ( Iholdcap I sub h o l d end-sub ): 1.1A.
Common Packages: SMD 1206 or similar surface-mount footprints.
Typical Manufacturer: Polytronics (e.g., SMD1206P110TFT) or Tyco Electronics (Raychem). Technical Schematic Context f4901 1.1a 24v schematic
In laptop schematics (e.g., Dell Inspiron N5110, Lenovo G580), F4901 is typically located in the USB power delivery or LCD backlight circuit paths. Circuit Placement
USB Power Protection: It is often placed on the +5V line for USB ports (like USB_PP0_C) to prevent overcurrent damage to the motherboard if a faulty peripheral is connected. Input/Output:
Input Side: Connected to the system's power rail (e.g., 5V_S0 or DCBATOUT depending on the specific sub-circuit).
Output Side: Connected directly to the VCC pin of a USB connector or the backlight power pin of an LVDS/EDP connector. Troubleshooting & Failure Analysis If a device is experiencing power issues related to F4901:
Symptoms: USB ports not providing power, "USB Power Surge" errors in Windows, or a dark laptop screen (no backlight).
Testing: Use a multimeter in continuity mode. A healthy F4901 should show very low resistance (near 0 ohms). High resistance or an "open" reading indicates the fuse has tripped or failed. Does the schematic protect your device
Resetting: Being a PTC, it should automatically reset once the short circuit or overcurrent condition is removed and the component cools down. If it remains "open," it must be replaced.
📌 Visual Reference: You can find the exact placement of this component by searching for the Wistron "Queen" or "Hummingbird" motherboard schematics, specifically looking at the USB or LCD Connector pages.
The identifier F4901 1.1A 24V refers to a specific silk-screened marking found on the motherboard of several laptop models, most notably the Acer Aspire 5560 and 5560G. In technical contexts, "F4901" typically designates a surface-mount fuse (F) on the board's power rail, rated for 1.1 Amps and a maximum voltage of 24 Volts. Motherboard Context
While the "F4901" code is widely searched, it is part of a larger motherboard architecture known as the Wistron JE50_SB. If you are looking for a complete schematic to troubleshoot power issues or backlight failure, you should search for the JE50_SB Schematic and Block Diagram. Key Specifications of the F4901 Component
On these laptop boards, this component is often a fast-acting fuse protecting the backlight circuit or a specific low-power voltage rail. Designation: F4901 (Fuse 4901) Current Rating: 1.1 Amps (1.1A) Voltage Rating: 24 Volts (24V) Common Use: Backlight power protection for LCD/LED panels. Troubleshooting with the Schematic
When a laptop like the Acer Aspire 5560G experiences a "black screen" but still powers on, technicians often check the F4901 fuse for continuity. If this fuse is blown, it breaks the circuit for the screen's backlight. When you look for a schematic, ensure it
Locate the Fuse: Find the component marked "F4901" near the LVDS/LCD connector on the motherboard.
Test Continuity: Use a multimeter to check if the fuse is "open."
Reference the JE50_SB Schematic: For exact pinouts and related power rails (like the 19V or 3.3V lines), consult the official JE50_SB Schematic PDF. Related Motherboard Components On the JE50_SB board, you may also encounter: PL9201: A power inductor often associated with GPU voltage. BIOS Chip: Frequently identified as MX25L1605.
Power Controllers: Such as the ISL6267 or RT8207 for various voltage steps.
Acer Aspire 5560G черный экран • Notebook1 форум
In the world of compact switched-mode power supplies (SMPS), the F4901 1.1A 24V module has carved out a niche as a reliable, low-power workhorse. You will often find this driver inside LED lighting systems, small CNC spindle controllers, 3D printers, and industrial control panels. However, despite its prevalence, finding a clean, readable f4901 1.1a 24v schematic can be a daunting task. Most modules are potted in epoxy or feature obscure proprietary IC markings.
This article serves two purposes. First, we will reconstruct a generic but highly accurate schematic based on common reverse-engineered boards. Second, we will provide a functional analysis, common failure points, and repair strategies for this specific power supply topology.
+-----------------+
| AC Input (L) |
+--------+--------+
|
F1 (Fuse 1.5A Slow)
|
+----+----+
| L1 (Common Mode Choke)
+----+----+
| |
C1 (X2) |
| |
+----+----+
| Bridge Rectifier (DB1) |
+----+----+
| |
C2 (100uF/400V)
|
+---+---+
| R2 (Startup Resistor - 150k)|
+---+---+
|
Primary Side IC (PWM Controller - Likely OB2263 or AP8012H)
|
+---+---+ +---------+
| Q1 (MOSFET - 4N60)|-----| T1 (Transformer) |
+---+---+ +----+----+
| |
R3 (Current Sense - 0.68 Ohm) |
| |
GND Secondary Winding
|
+---+---+
| D1 (Schottky Diode - SB3100)|
+---+---+
|
C3 (470uF/35V)
|
+---+---+
| R4 (Load Resistor - 1k)|
+---+---+
|
+---+---+
| U2 (Optocoupler - PC817)|
+---+---+
|
+---+---+
| U3 (Voltage Ref - TL431)|
+---+---+
|
R5 & R6 (Voltage Divider for 24V)
|
24V DC Output (+)
GND Secondary (-)
If you are repairing a device or building a circuit around the F4901: