The HP FXN1 E93839 (often associated with the HP ProDesk or EliteDesk series) is an OEM motherboard designed for business-class desktops. It is built for reliability and standard office tasks rather than high-end gaming or heavy workstation use.  Core Specifications  Socket: Intel LGA 1151

Chipset: Intel Q270 (typically found in the G3 series of HP business desktops)

Form Factor: Proprietary (designed specifically for HP SFF or MT chassis) Processor Support: 6th Generation Intel Core (Skylake) 7th Generation Intel Core (Kaby Lake) Supports i3, i5, i7, Pentium, and Celeron processors  Memory (RAM)  Slots: 4 DIMM slots Type: DDR4 SDRAM Speed: Supports up to 2400 MHz (depending on the CPU) Maximum Capacity: Up to 64 GB  Expansion & Connectivity  PCI Express Slots: 1 x PCIe x16 (for dedicated graphics) 1 x PCIe x4 1 x M.2 PCIe x4 (specifically for high-speed NVMe SSDs) Storage: 3 to 4 SATA III (6.0 Gb/s) ports Networking: Integrated Intel I219LM Gigabit Ethernet  Rear I/O Panel (Common Configuration)  USB: Multiple USB 3.0/3.1 Gen 1 ports

Video: 2 x DisplayPort, 1 x VGA (optional in some configurations) Audio: Line-in and Line-out jacks

Legacy: PS/2 ports for keyboard and mouse (on specific models)  Important Note on Compatibility 

Because this is a proprietary HP motherboard, it uses a non-standard power connector. You cannot use a standard ATX power supply without a specialized adapter. Additionally, the mounting holes may not align with standard ATX or Micro-ATX cases. 

To give you the most accurate details for your specific setup, could you tell me:  Are you looking to upgrade the CPU or RAM? Do you need to know if a specific graphics card will fit?

What is the model name of the PC case it came out of (e.g., HP ProDesk 600 G3)? 

This is a detailed guide to the HP FXM1 (also labeled E93839) motherboard. This board is most commonly found in HP All-in-One (AIO) desktop PCs, specifically the HP 22-xxxx and HP 24-xxxx series (e.g., HP 22-b2xx, 24-f0xx).

Before diving in: FXM1 and E93839 refer to the same PCB. E93839 is often the spare part number, while FXM1 is the model/board number.

Why it's useful:

• Direct Panel Connection: Unlike standard desktop boards, this motherboard can drive a laptop/All-in-One LCD panel directly—no separate display controller or driver board needed.
• Repair/Upgrade AiO Screens: If the original screen fails, you can connect a compatible LVDS panel (single/dual channel, 30-pin or 40-pin) using the internal header.
• DIY Portable Monitor: With a compatible LCD panel and a 12V power source, you can turn this board + panel into a compact, integrated system without needing an external monitor.

Chapter 5: Connectivity and I/O

The "I/O Shield" area (the back of the PC) tells the story of transition.

• PS/2 Ports: The board stubbornly retains the purple and green circular ports for the keyboard and mouse. Why? Because in 2008, businesses had warehouses full of expensive, mechanical keyboards and rugged mice that still used these legacy ports. HP was catering to the "if it ain't broke, don't fix it" crowd.
• USB 2.0: There are usually six to eight USB 2.0 ports. Note the version: 2.0. This was the standard before the blue ports of USB 3.0 arrived. Fast enough for flash drives and printers, but slow by today's standards.
• The LAN: An RJ-45 port, usually powered by a Realtek chipset, ensured the PC could jack into the corporate intranet at 10/100 or 1000 Mbps speeds.
• Audio: Six 3.5mm jacks powered by Realtek, offering 5.1 or 7.1 surround sound—overkill for a secretary, perfect for a media center build.

Chapter 1: The Identity Crisis (The Name)

The alphanumeric soup—"FXN1" and "E93839"—tells a story of globalization. "E93839" is the HP spare part number, a code used by warehouse logistics and IT repairmen. "FXN1" is often the platform name used by the manufacturer, Pegatron (a major OEM partner of HP).

This motherboard is the heart of the HP Compaq dx2400 Microtower. It was a "budget business" machine. It wasn't pretty, but it was reliable. When you look at the board, you aren't looking at a performance racer; you are looking at a workhorse.

6. Expansion Slots: What Can You Add?

Despite being a budget OEM board, the FXN1 offers three expansion slots:

1. PCI Express x16 (physical x16, wiring may be x8 or x16) – For a graphics card.
   • Limitation: The PSU in HP Pavilion desktops is typically weak (180W-300W). You can install a low-power GPU like the GTX 1650 (75W version), RX 6400, or GT 1030. Avoid cards requiring a 6-pin PCIe power connector unless you replace the power supply.
2. PCI Express x1 – For USB 3.0 expansion cards, sound cards, or Ethernet adapters.
3. Legacy PCI (32-bit) – For older Wi-Fi cards, TV tuners, or audio interfaces. This is rare on modern motherboards.

GPU Upgrade Warning: The PCIe slot is physically x16 but may run at PCIe 2.0 speed (5 GT/s) depending on the CPU, not PCIe 3.0. A modern budget GPU will still work but may see a 5-10% performance loss.

11. Final Verdict: Is the HP FXN1 (E93839) Worth Keeping in 2025?

Yes, as a budget machine. No, for a modern gaming or workstation build.

Keep it if:

• You have it in an old HP Pavilion case.
• You want a super cheap web browsing, office, or light emulation PC.
• You can find a used i7-4770 and 16GB DDR3 for under $40 total.

Replace it if:

• You want NVMe SSD booting.
• You need more than 2 RAM slots (32GB+).
• You want to overclock or use a high-power GPU.
• The proprietary PSU has died (replacing the board with a standard H81/B85 might be cheaper).

4. Storage Options

| Interface | Details | |-----------|---------| | SATA 3.0 | 1 x 2.5” drive bay (7mm or 9.5mm height). Uses a proprietary combo power/data ribbon cable. | | M.2 slot | Key M. Supports SATA SSD (B+M key) or NVMe PCIe 2.0 x2/x4 (depends on BIOS). Many boards only do SATA on M.2. | | M.2 length | 2280 (full length) | | Boot order | Can boot from SATA or M.2. BIOS may limit NVMe boot on earlier revisions. |

Recommendation: Replace HDD with SATA SSD for best performance. M.2 NVMe may not be recognized – test before buying.

4. RAM Specifications & Upgrade Path

The HP FXN1 E93839 is picky about RAM. It only has two DIMM slots, so you cannot run four sticks of RAM.

• Maximum Capacity: 16GB (2 x 8GB modules).
• Type: DDR3, 1.5V (low-voltage 1.35V DDR3L may work but is not officially supported in all BIOS versions).
• Speed: 1600MHz modules will work but may be downclocked to 1333MHz if you install a CPU with a slower memory controller (e.g., an i3 or Pentium).
• Dual Channel: For best performance, install matched pairs (same capacity, same speed, same brand).

What to Avoid:

• ECC (Error Correcting Code) RAM – not supported.
• DDR2 or DDR4 – physically incompatible.
• Mixing RAM sizes (e.g., 4GB + 8GB) – forces single-channel mode, reducing memory bandwidth by up to 50%.

Recommended Upgrade: Corsair Vengeance or Kingston HyperX DDR3 1600MHz (2x8GB kit).

2. Detailed Technical Specifications

Here is the complete breakdown of the HP FXN1 E93839 motherboard’s specifications.

| Feature | Specification | | :--- | :--- | | Manufacturer | Hewlett-Packard (HP) | | Model / PCB | FXN1 | | Part Number | E93839 | | CPU Socket | LGA 1150 | | Chipset | Intel H87 Express | | Compatible Processors | Intel Core i7-4xxx, i5-4xxx, i3-4xxx, Pentium G3xxx, Celeron G18xx (Haswell & Haswell Refresh only — NOT compatible with Broadwell/6th gen) | | Memory Slots | 2 x DDR3 DIMM (240-pin) | | Memory Type | DDR3 (Non-ECC, Unbuffered) | | Memory Speed | 1333 MHz, 1600 MHz (downclocks to 1333 depending on CPU) | | Max Memory Support | 16 GB (2 x 8GB modules) | | Memory Architecture | Dual-channel | | Expansion Slots | 1 x PCIe x16 (v2.0/v3.0), 1 x PCIe x1, 1 x PCI (32-bit legacy) | | Storage Interfaces | 4 x SATA 3.0 (6 Gb/s), 1 x SATA 2.0 (3 Gb/s — often for optical drive) | | M.2 Slot | No | | Rear I/O | 1 x PS/2 (keyboard), 1 x VGA, 1 x DVI-D, 1 x HDMI, 4 x USB 2.0, 2 x USB 3.0, 1 x RJ45 Ethernet, 3 x Audio jacks | | USB Headers (Internal) | 2 x USB 2.0, 1 x USB 3.0 | | Audio Codec | Realtek ALC662 (5.1 channel HD Audio) | | LAN / Ethernet | Realtek RTL8111HSH (Gigabit) | | BIOS | AMI (American Megatrends) with HP UEFI interface | | Power Connectors | 1 x 24-pin ATX (proprietary pinout possible), 1 x 4-pin CPU (12V) |