2 layers19 × 76 mm
Sub
google/mozc-devices
Circuit diagrams and firmware source code for Gboard DIY keyboards
15 parts3kApache-2.0
2 layers75.6 × 17.1 mm
ATX Boot Delay
mwrnd/ATX_Boot_Delay3Power-On Boot Delay for ATX Motherboards with 9-Pin Front Panel Header
- Size
- 75.6 × 17.1 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 15
- Nets
- 18
- Pads
- 54
- Tracks, vias
- 270, 27
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 14 Dec 2023
- Updated
- 17 Mar 2024
Overview
ATX Boot Delay is an open-source printed circuit board by mwrnd, from the mwrnd/ATX_Boot_Delay repository on GitHub, published under the BSD-2-Clause licence. It is a 2-layer board of 75.6 × 17.1 mm with 15 parts on 18 nets, routed with 270 tracks and 27 vias.
Its parts include 4 resistors, 3 capacitors, 3 connectors, 2 diodes and 2 switches. It belongs with the computers and single-board computers boards of this library.
README
README.mdATX Boot Delay
Delaying a motherboard's BIOS/UEFI boot is a simple trick that solves issues related to the PCIe Specification's 100ms time limit. This can be done by toggling a computer's POWER button, then pressing and holding the RESET button for a second before releasing it. Or, connect a capacitor across the reset pins of an ATX motherboard's Front Panel Header.
This board is a simple 9-Pin Front Panel Header in-line replacement for ATX motherboards that allows choosing capacitor(s) to connect accross the RESET pins to delay boot.
To use the RESET button on the board, hold it long enough to overcome the capacitor discharge delay which can be a couple of seconds.
Usage Example
Close-up:
PCB Layout
Schematic
Bill Of Materials
| Designator(s) | Part Number | Quantity | Value | Footprint | Availability |
|---|---|---|---|---|---|
| C1 | 860010674014 | 1 | 100uF | C_Radial_D8.0mm_H11.5mm_P3.50mm | DigiKey |
| C2 | 860010374011 | 1 | 330uF | C_Radial_D8.0mm_H11.5mm_P3.50mm | DigiKey |
| C3 | 860020274013 | 1 | 680uF | C_Radial_D8.0mm_H11.5mm_P3.50mm | DigiKey |
| C4 | 860010274015 | 1 | 1000uF | C_Radial_D8.0mm_H11.5mm_P3.50mm | DigiKey |
| SW1, SW2 | TS02-66-60-BK-100-LCR-D | 2 | N/A | SW_PUSH_6mm | DigiKey |
| J1 | PREC005DBAN-M71RC | 1 | N/A | PinSocket_2x05_P2.54mm_Horizontal | DigiKey |
| J2 | PPTC052LJBN-RC | 1 | N/A | PinHeader_2x05_P2.54mm_Horizontal | DigiKey |
| J3 | 9-146257-0-04 | 1 | N/A | PinHeader_2x04_P2.54mm_Vertical | DigiKey |
| D1 | C503B-RAN-CZ0C0AA2 | 1 | RED | LED_D5.0mm | DigiKey |
| D2 | LTL-4234 | 1 | GREEN | LED_D5.0mm | DigiKey |
| R1, R2, R3 | CF14JT220R | 1 | 220-Ohm | R_Axial_DIN0207_L6.3mm_D2.5mm | DigiKey |
| Jumpers | QPC02SXGN-RC | 4 | N/A | N/A | DigiKey |
Theory of Operation
The capacitor across RESET works thanks to an RC Delay on the reset signal buffer. The OpenCompute project has a public schematic and the RESET Button is on Pg#151 in Project_Olympus_Intel_XSP_Schematics_20171016.pdf found in Project_Olympus_Intel_XSP_Collateral.zip.
A standard Schmitt-Trigger inverter such as the SN74LVC1G14 has a positive-going threshold voltage of about 1.5V with a 3.3V supply. I have measured 1k-Ohm between the RESET+ pin and the 3.3V ATX Power supply rail. A 330uF capacitor therefore delays boot by about 200ms. RC Calculator:
I found out about this technique here:
Parts
15| Qty | Value | Footprint | References |
|---|---|---|---|
| 1 | 1000u | Capacitor_THT:C_Radial_D8.0mm_H11.5mm_P3.50mm | C3 |
| 1 | 110 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1 |
| 1 | 220 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R2 |
| 1 | 330 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R3 |
| 1 | 330u | Capacitor_THT:C_Radial_D8.0mm_H11.5mm_P3.50mm | C1 |
| 1 | 680u | Capacitor_THT:C_Radial_D8.0mm_H11.5mm_P3.50mm | C2 |
| 1 | 7.5 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R0 |
| 1 | ATX_FP | Connector_PinHeader_2.54mm:PinHeader_2x05_P2.54mm_Horizontal | J1 |
| 1 | ATX_FP | Connector_PinSocket_2.54mm:PinSocket_2x05_P2.54mm_Horizontal | J2 |
| 1 | HDD | LED_THT:LED_D5.0mm | D2 |
| 1 | M3 | MountingHole:MountingHole_3.2mm_M3_Pad_TopOnly | H1 |
| 1 | POWER | Button_Switch_THT:SW_PUSH_6mm | SW1 |
| 1 | POWER | LED_THT:LED_D5.0mm | D1 |
| 1 | RESET | Button_Switch_THT:SW_PUSH_6mm | SW2 |
| 1 | SELECT | Connector_PinHeader_2.54mm:PinHeader_2x03_P2.54mm_Vertical | J3 |
Questions
How big is the ATX Boot Delay PCB?
It measures 75.6 × 17.1 mm and has 2 copper layers, 1.6 mm thick.
What parts does the ATX Boot Delay use?
15 parts. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the ATX Boot Delay KiCad files?
From the mwrnd/ATX_Boot_Delay repository on GitHub, at the commit this page was made from: the board is ATX_Boot_Delay.kicad_pcb and its schematic ATX_Boot_Delay.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the ATX Boot Delay design in my own project?
Its repository publishes it under the BSD-2-Clause licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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