The Pegatron M2N78-LA (also known by its HP/Compaq code names Violet-GL8E or Violet6-GL8E) is a Micro-ATX motherboard frequently found in HP Pavilion and Compaq Presario desktop systems.
Designed for AMD processors, this motherboard had two primary revisions: an earlier version supporting Socket AM2/AM2+ with DDR2 memory and a later "Violet6" version supporting Socket AM3 with DDR3 memory. Below is a comprehensive guide based on the M2N78-LA Motherboard Manual. Key Technical Specifications Revision 3.xx (AM2/DDR2) Revision 5.xx/6.xx (AM3/DDR3) Socket AM2 / AM2+ Chipset NVIDIA GeForce 9100 NVIDIA GeForce 9100 Memory 4x DDR2 DIMM (Up to 16GB) 4x DDR3 DIMM (Up to 16GB) Expansion 1x PCIe x16, 3x PCIe x1 1x PCIe x16, 2x PCIe x1, 1x PCI Form Factor Micro-ATX (24.4 x 24.4 cm) Micro-ATX (24.4 x 24.4 cm) Top Troubleshooting & Setup Procedures 1. Front Panel Header Pinout
The front panel connector is a 9-pin header typically located at the bottom-right of the board. If you are moving this board to a new case, use this standard configuration: HDD LED: Pins 1 (+) and 3 (-) Power LED: Pins 2 (+) and 4 (-) Reset Switch: Pins 5 and 7 Power Switch: Pins 6 and 8 Pin 9: Reserved/Ground; Pin 10: Empty (Key) 2. Clearing CMOS Settings
If the system fails to post or you need to reset BIOS to factory defaults, follow the CMOS clearing instructions: Turn off the computer and unplug the power cord. Locate the CLEAR_CMOS jumper (often near the battery). Move the jumper from its default pins 2-3 to pins 1-2. Wait 5–10 seconds, then return the jumper to pins 2-3. Plug in the power and restart. 3. BIOS Password Reset
To remove a forgotten BIOS password, locate the CLEAR P.W. jumper: Move the jumper to pins 1-2 for 10 seconds.
Return the jumper to pins 2-3 before powering the system back on. Upgrade Limitations & Compatibility
CPU Support: The AM3 version (Violet6) supports Phenom II, Athlon II, and Sempron processors with a TDP of up to 95W.
Memory Speed: While it supports DDR3-1333, the system will automatically downclock to 1066 MHz if three or more modules are installed due to AMD platform limitations.
Graphics: The integrated NVIDIA 9100 is automatically disabled if a dedicated card is installed in the PCI Express x16 slot. pegatron motherboard m2n78la manual top
Storage: The board features 4 SATA connectors (SATA II - 3.0 Gb/s) and one legacy floppy drive connector on older revisions.
For detailed wiring diagrams and visual layout, you can reference the HP Desktop Support Archive or download the technical PDF from The Retro Web. Pegatron M2N78-LA Motherboard Specs | PDF - Scribd
: If three or more modules are installed, DDR3-1333 will downclock to 1066 MHz due to AMD controller limitations. Earlier Revisions
: Some versions use DDR2 memory (PC2-6400/800 MHz or PC2-5300/667 MHz). The Retro Web Internal Connectors & Slots 1x PCI Express x16 (for graphics). 2x PCI Express x1. 1x PCI slot. 1x PCI Express x1 mini card socket. : 4x SATA connectors. : 1x 24-pin ATX main power and 1x 4-pin ATX CPU power. Rear I/O Ports : 1x VGA and 1x DVI. : 4x USB 2.0 ports. Networking : 1x RJ-45 Ethernet (Realtek RTL8201N 10/100 Mb/s).
: 6-port audio jack (Realtek ALC888S 8-channel HD audio) and 1x S/PDIF coaxial out. : 1x IEEE 1394 (FireWire). Maintenance & Jumper Settings Clear CMOS Turn off the PC and unplug the power cord. CLEAR_CMOS jumper to pins 1-2. Wait 5–10 seconds, then return it to pins 2-3. Clear BIOS Password : Locate the
jumper. Move from pins 2-3 to pins 1-2 for 10 seconds, then return. Front Panel Header
: A 9-pin header handles the power button, reset, and LED indicators. Polarity matters for LEDs but not for the power/reset switches. device.report
Full manual PDFs and driver updates can often be found through the HP Support Portal The Pegatron M2N78-LA (also known by its HP/Compaq
by searching for your specific desktop model number (e.g., Pavilion p6130f) or via legacy archives like The Retro Web pinout diagram for the front panel or a specific list of compatible AM3 CPUs Motherboard Specifications, M2N78-LA (Violet6)
The Pegatron M2N78-LA is a popular Micro-ATX motherboard commonly found in HP and Compaq desktop systems, such as the Pavilion and Presario series. Known by the HP codenames Violet-GL8E (Rev 3.02) and Violet6 (Rev 6.01), this board was a staple for AMD-based budget and mid-range builds during the late 2000s.
If you are looking for the Pegatron M2N78-LA manual or key specifications to upgrade an older machine, this guide covers everything from CPU compatibility to front panel headers. Core Specifications Overview
The motherboard is built around the NVIDIA GeForce 9100 chipset. It typically follows a Micro-ATX form factor (24.4 cm x 24.4 cm), making it compatible with most standard desktop cases. Rev 3.02 (Violet) Rev 6.01 (Violet6) CPU Socket Socket AM2 / AM2+ Socket AM3 Memory Type DDR2 (Up to 800 MHz) DDR3 (Up to 1333 MHz) Max RAM 16 GB (4 slots) 16 GB (4 slots) Chipset NVIDIA GeForce 9100 NVIDIA GeForce 9100 Graphics Integrated GeForce 9100 Integrated GeForce 9100 CPU Support and Upgrades Compatibility depends heavily on your specific revision. M2N78-LA motherboard, which CPU phenom is compatible
Pegatron M2N78LA Motherboard Manual
Table of Contents
1. Introduction
Congratulations on purchasing the Pegatron M2N78LA motherboard! This manual will guide you through the installation and configuration of your new motherboard. skinned by HP. To enter BIOS
2. Motherboard Layout
The Pegatron M2N78LA motherboard is designed with the NVIDIA nForce 780L chipset, supporting AMD Socket AM2+ processors. The motherboard layout is as follows:
3. Hardware Installation
This section will guide you through the installation of the motherboard and its components.
The board has two internal USB 2.0 headers (9-pin). Pin 1 is top left (Power), Pin 10 is bottom right (Ground). The missing pin (Pin 9) is the key.
Cause: Unseated RAM or unsupported DDR2. Fix: The M2N78LA does not like double-sided high-density RAM. Use "low density" 2GB sticks. Also, populate the slots as DIMM1 and DIMM3 (white slots) first, not the black ones.
Cause: Short circuit or CPU failure. Fix: Check the standoffs under the motherboard. Also, remove the CPU power connector (4-pin/8-pin) and plug it back in. This board is sensitive to over-current.
| Feature | Details | |---------|---------| | Form Factor | Micro-ATX | | CPU Socket | AM2+ (supports AM2 CPUs like Athlon 64 X2, Phenom) | | RAM | 4 x DDR2 DIMMs (max 16GB, PC2-6400) | | Chipset | NVIDIA GeForce 9100 / nForce 720a | | Expansion | 1x PCIe x16, 2x PCIe x1, 1x PCI | | Rear I/O | VGA, HDMI, 6x USB 2.0, Audio (6-jack), LAN |
Yes. The top workaround: You must install via Legacy BIOS (not UEFI). Use the NVIDIA nForce Driver v15.56 (modified) for SATA and LAN. Sound requires a Realtek HD Audio driver from 2015.
The M2N78LA uses an American Megatrends (AMI) BIOS, skinned by HP. To enter BIOS, press F10 repeatedly during boot (not Delete, as many manuals suggest).