HP Pro 3500 MT Motherboard Pinouts 2024/04/22 Last Updated: 2024/04/25 [0422] Added Front Panel Pinout (unfinished; copypasted from Lenovo H520/K410) Added CPU Fan Pinout [0424] Added 24-Pin ATX Pinout Added EPS12V Pinout Added Front USB Pinout Finished Front Panel Pinout Added Front Audio Pinout [0425] Updated Front USB Pinout (now that I have the motherboard in hand...) Fixed 4-pin CPU fan pinout (was reversed) --- Front Panel Pinout Named F_PANEL [Standard Pinout] +-----+-----+-----+-----+-----+ | | | | | X | | 2 | 4 | 6 | 8 | 10 | | | | | | X | +-----+-----+-----+-----+-----+ | | | | | | | 1 | 3 | 5 | 7 | 9 | | | | | | | +-----+-----+-----+-----+-----+ 1 - HDD LED + 3 - HDD LED - 2 - Power LED + 4 - Power LED - 5 - Reset SW - 7 - Reset SW + 6 - Power SW + 8 - Power SW - -- Front Audio Pinout Named F_AUDIO [Standard Pinout] Note 1: If not using an Intel HD Audio front panel header, you may jumper pins 2 and 4 with a jumper, otherwise the system will bug you with '917-Front Audio Not Connected' upon startup. Note 2: This is ONLY an Intel HD Audio connector, so do not connect an AC97 header to this connector! +-----+-----+-----+-----+-----+ | | | | X | | | 2 | 4 | 6 | 8 | 10 | | | | | X | | +-----+-----+-----+-----+-----+ | | | | | | | 1 | 3 | 5 | 7 | 9 | | | | | | | +-----+-----+-----+-----+-----+ 1 - PORT1_L 2 - AUD_GND 3 - PORT1_R 4 - PRESENCE_J 5 - PORT2_R 6 - SENSE1_RETURN 7 - SENSE_SEND 8 - KEY (N/A, Empty) 9 - PORT2_L 10 - SENSE2_RETURN -- Front USB Pinout (Double Header) Named F_USB1 Named F_USB2 [Standard Pinout... mostly] Note 1: Pin 11 and 12 may need to be tied to GND, otherwise the system will bug you with '918-Front USB Not Connected' upon startup. Note 2: It is currently unknown as to how ID is tied. A theory is they are just shorted to GND. An original header is needed in order to figure this out. +-----+-----+-----+-----+-----+-----+ | | | | | X | | | 2 | 4 | 6 | 8 | 10 | 12 | | | | | | X | | +-----+-----+-----+-----+-----+-----+ | | | | | | | | 1 | 3 | 5 | 7 | 9 | 11 | | | | | | | | +-----+-----+-----+-----+-----+-----+ 1 - +5V 2 - +5V 3 - Data - 4 - Data - 5 - Data + 6 - Data + 7 - GND 8 - GND 9 - Key (N/A, Empty) 10 - Key (N/A, Empty) 11 - ID - tied to pin 7 12 - ID - tied to pin 8 -- Front USB Pinout (Single Header) Named F_USB3 [Standard Pinout... mostly] Note 1: Pin 6 may need to be tied to GND, otherwise the system will bug you with '918-Front USB Not Connected' upon startup. Note 2: It is currently unknown as to how ID is tied. A theory is they are just shorted to GND. An original header is needed in order to figure this out. +-----+-----+-----+-----+-----+-----+ | | | | | X | | | 1 | 2 | 3 | 4 | 5 | 6 | | | | | | X | | +-----+-----+-----+-----+-----+-----+ 1 - +5V 2 - Data - 3 - Data + 4 - GND 5 - Key (N/A, Empty) 6 - ID - tied to pin 4 -- CPU Fan Pinout Named CPU_FAN [Standard Pinout] +-----+-----+-----+-----+ | | | | | | 1 | 2 | 3 | 4 | | | | | | +-----+-----+-----+-----+ 1 GND 2 +12V 3 TACH 4 PWM -- PSU Pinout Named ATX_POWER [Standard Pinout] +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | | | | | | | | | | | | | | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | | | | | | | | | | | | | | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | | | | | | | | | | | | | | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | | | | | | | | | | | | | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ 1 - +3.3V 2 - +3.3V 3 - GND 4 - +5V 5 - GND 6 - +5V 7 - GND 8 - POK (Power Good) 9 - +5Vaux (+5VSB) 10 - +12V 11 - +12V 12 - +3.3V 13 - +3.3V 14 - –12V 15 - GND 16 - PSON (Power Supply On) 17 - GND 18 - GND 19 - GND 20 - open (N/A; historically -5V) 21 - +5V 22 - +5V 23 - +5V 24 - GND -- EPS12V Pinout (4 Pin version) Named ATX_CPU [Standard Pinout] +-----+-----+ | | | | 4 | 3 | | | | +-----+-----+ | | | | 2 | 1 | | | | +-----+-----+ 1 - GND 2 - GND 3 - +12V CPU 4 - -12V CPU