Tracks the 1.5V DDR3 rail and its corresponding termination voltages. Standby Rails: Visualizes the +3.3VSBpositive 3.3 cap V cap S cap B +5VSBpositive 5 cap V cap S cap B
A short circuit in the CPU phases will trip the power supply's Over-Current Protection (OCP), causing the fans to spin for a fraction of a second before shutting down.
Engineered for 2nd and 3rd Generation Intel Core processors (Sandy Bridge/Ivy Bridge) using Q77 Express chipsets.
The E93839 uses standard AMI or Phoenix BIOS frameworks depending on the HP/Compaq firmware flash.
As confirmed in the official Dell community forums, this code is in fact a , the Original Design Manufacturer (ODM) that produced the board. Foxconn uses the "E93839" identifier on a vast number of its reference designs. Consequently, Dell then customized and implemented these same base designs across a wide range of its OptiPlex desktop lines over many years. e93839 motherboard schematic updated
Check respective pins on the 24-pin ATX connector or output inductors (coils).
Usually a Fintek, Nuvoton, or ITE IC that manages low-level hardware monitoring, fan speed controls, temperature sensors, and the critical power-on sequence. Understanding the Motherboard Power Rails
For technical repair schematics, check enthusiast forums like BadCaps or VinaFix using your true part number (e.g., "Dell Optiplex 790 schematic") instead of E93839.
If you are using the , follow this checklist to repair your board: Tracks the 1
The E93839 motherboard is a widely used, legacy OEM board manufactured by Foxconn, commonly found in older Hewlett-Packard (HP) and Compaq desktop computers. Because it was distributed as an Original Equipment Manufacturer component, official documentation and wiring diagrams were never openly published for consumers. Finding an updated schematic is essential for repairing power delivery failures, diagnosing boot loops, or modifying the board for modern use cases.
Feeds the multi-phase VRM (Voltage Regulator Module) to create VCC_CORE (typically 1.0V–1.3V) for the processor.
: Often includes an M.2 PCIe NVMe slot for high-speed boot drives. HP Support Community 3. Expansion & Connectivity Expansion Slots 1x PCIe x16 (for dedicated graphics cards). 1x PCIe x1 or x4 (for networking or sound cards). Rear I/O Ports : Multiple DisplayPort outputs (VGA is sometimes optional/add-on). : A mix of USB 2.0 and USB 3.0/3.1 ports; newer revisions may include a
Historically, finding a schematic for an OEM desktop motherboard was nearly impossible, as manufacturers rarely made them public. You will often encounter dead ends on community forums, where senior users bluntly state that "Dell schematics aren't available for anything remotely modern". This lack of official support has led to the growth of specialized third-party platforms where updated schematics and boardview files are shared. The E93839 uses standard AMI or Phoenix BIOS
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The standby voltage rail that remains active as long as the power supply is connected to AC mains. This powers the SIO chip and the Southbridge/PCH standby circuit, allowing the board to detect the power button press. Secondary Derived Rails
Open the Windows System Information app and check the "BaseBoard Product" field. 2. Common E93839 Board Specifications
In Q1 2025, a collective of European repair technicians began converting the e93839 schematic into an . This "living schematic" allows users to simulate the power rail using ngspice. The updated version we have today is likely the final PDF revision, but the KiCad port promises:
