LVDS2HD - Revision history

Admin: Replace with

2026-05-27T02:12:50Z

Replace <comments/> with <comment-streams />

← Older revision		Revision as of 10:12, 27 May 2026
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	<!--Add review function! -->		<!--Add review function! -->
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Admin: Replace with

2026-05-26T12:06:55Z

Replace <comments/> with <comment-streams />

← Older revision		Revision as of 20:06, 26 May 2026
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	<!--Add review function! -->		<!--Add review function! -->
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Ruby: /* User Manual */

2026-02-25T02:59:31Z

User Manual

← Older revision		Revision as of 10:59, 25 February 2026
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	<mark>3.</mark> If D2 fails to light up and there’s no HDMI output after power-on, the possible causes are:		<mark>3.</mark> If D2 fails to light up and there’s no HDMI output after power-on, the possible causes are:

	(1)Incorrect single/dual-channel configuration (R20);		(1) Incorrect single/dual-channel configuration (R20);

	(2)Mismatched LVDS wire sequence;		(2) Mismatched LVDS wire sequence;

	(3)Short-circuit R21 and retest (for VESA/JEIDA mapping);		(3) Short-circuit R21 and retest (for VESA/JEIDA mapping);

	(4)Differential pair polarity (+/−) reversed (Fix: First swap only O2+/O2− and OCLK+/OCLK−. If D2 lights up after swapping, polarity is correct; then swap all remaining twisted pairs).		(4) Differential pair polarity (+/−) reversed (Fix: First swap only O2+/O2− and OCLK+/OCLK−. If D2 lights up after swapping, polarity is correct; then swap all remaining twisted pairs).

	'''Double-check to ensure correct wiring and configurations.'''		'''Double-check to ensure correct wiring and configurations.'''
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	'''If the debug print scrolls continuously, the cause is definitely unstable LVDS signals''', resulting in changes to the 5 parameters shown above:		'''If the debug print scrolls continuously, the cause is definitely unstable LVDS signals''', resulting in changes to the 5 parameters shown above:

	(1)Ensure LVDS differential pairs use twisted pairs and are free from interference.		(1) Ensure LVDS differential pairs use twisted pairs and are free from interference.

	(2)If InputPclk fluctuates, check if SSC (Spread Spectrum Clocking) is enabled; disable it for testing if possible.		(2) If InputPclk fluctuates, check if SSC (Spread Spectrum Clocking) is enabled; disable it for testing if possible.

	(3)If HTotal or VTotal fluctuates, check the synchronization mode in software settings (usually Freerun or FrameLock). For LVDS-to-HDMI output, the mode must be Freerun with fixed HTotal/VTotal. For direct LVDS display, HTotal/VTotal may vary within a limited range without affecting the image. Thus, LVDS working for direct display does not guarantee valid LVDS-to-HDMI output.		(3) If HTotal or VTotal fluctuates, check the synchronization mode in software settings (usually Freerun or FrameLock). For LVDS-to-HDMI output, the mode must be Freerun with fixed HTotal/VTotal. For direct LVDS display, HTotal/VTotal may vary within a limited range without affecting the image. Thus, LVDS working for direct display does not guarantee valid LVDS-to-HDMI output.

Ruby: /* User Manual */

2026-02-10T10:12:47Z

User Manual

Ruby: /* User Manual */

2026-02-10T10:08:15Z

User Manual

← Older revision		Revision as of 18:08, 10 February 2026
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	* English User Manual:[[File:LVDS2HD-LVDS to HDMI-EN.pdf]]		* English User Manual:[[File:LVDS2HD-LVDS to HDMI-EN.pdf]]

			----
	'''CN3/CN4/CN6 Interface Definition'''		'''CN3/CN4/CN6 Interface Definition'''

Ruby: /* User Manual */

2026-02-10T10:07:57Z

User Manual

← Older revision		Revision as of 18:07, 10 February 2026
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	==User Manual==		==User Manual==
	* Dimensions source file (DXF): [[File:HDMI2LVDS-PCBLayout.dxf]] - You can view it with [https://viewer.autodesk.com/ Autodesk Viewer] online		* Dimensions source file (DXF): [[File:HDMI2LVDS-PCBLayout.dxf]] - You can view it with [https://viewer.autodesk.com/ Autodesk Viewer] online
			* Chinese User Manual:[[File:LVDS2HD-LVDS to HDMI-CN.pdf]]
			* English User Manual:[[File:LVDS2HD-LVDS to HDMI-EN.pdf]]

	'''CN3/CN4/CN6 Interface Definition'''		'''CN3/CN4/CN6 Interface Definition'''

Ruby: /* User Manual */

2026-02-10T09:59:39Z

User Manual

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 [[File:LVDS2-06.jpg|700px|LVDS2 Mode Selection]]
-'''D1&D2 LED Indicator'''
+----
-After power on, D1 flashes,it indicates that the MCU is working normally. After receiving the LVDS signal, D2 is always on.
+. There are two LEDs on the board. After power-on, D1 blinks indicating the MCU is working properly. D2 stays on when the LVDS signal is received. '''If D2 does not light up, it means no LVDS signal is received - - check the wire sequence.'''
-If D2 is not light on, it means that no LVDS signal is received, and the line sequence needs to be checked.
+[[File:LVDS2-07.png|700px|On-board LED]]
-[[File:LVDS2-07.png|700px|LVDS2]]
 ==FAQ==

Harry at 02:50, 30 January 2026

2026-01-30T02:50:28Z

← Older revision		Revision as of 10:50, 30 January 2026
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	Due to the wide variety of screens on the market, the EDID recognition of different screens may have compatibility issues, which may lead to incorrect screen colors or abnormal screens or no display.		Due to the wide variety of screens on the market, the EDID recognition of different screens may have compatibility issues, which may lead to incorrect screen colors or abnormal screens or no display.

	This ~~LVDS2~~ board convert LVDS input signal to HDMI output, the resolution is VESA standard in default. If you need change to single 8 mode, please short the R20 on the ~~LVDS2~~ board.		This LVDS2HD board convert LVDS input signal to HDMI output, the resolution is VESA standard in default. If you need change to single 8 mode, please short the R20 on the LVDS2HD board.

	Because it is the DIY product, so sometimes there may be the compatibility problem. When it shows no signal or no sound, it may be the compability problem.		Because it is the DIY product, so sometimes there may be the compatibility problem. When it shows no signal or no sound, it may be the compability problem.

Harry: Harry moved page LVDS2 to LVDS2HD

2026-01-30T01:34:45Z

Harry moved page LVDS2 to LVDS2HD

← Older revision		Revision as of 09:34, 30 January 2026
(No difference)

Ruby at 10:40, 10 November 2025

2025-11-10T10:40:43Z

← Older revision		Revision as of 18:40, 10 November 2025
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	[[File:LVDS2-07.png\|700px\|LVDS2]]		[[File:LVDS2-07.png\|700px\|LVDS2]]

			==FAQ==
			<div class="toccolours mw-collapsible mw-collapsed">
			<div style="font-weight:bold;line-height:1.0">
			Q1: After screen replacement, no HDMI output, but the indicators (D1 flashing, D2 solid) are functioning normally?
			</div>
			<div class="mw-collapsible-content">
			[[File:LVDS2-EN.jpg\|thumb\|right\|300px\|Log Information - click it to zoom out]]
			<span class="tb_red">A:Please print the log information as instructed (Refer to the image)</span>

			-Connect the board's TX and GND to the PC via a USB-to-UART TTL cable. Set baud rate to 115200 and monitor for debug messages

			</div>
			</div>

← Older revision		Revision as of 18:12, 10 February 2026
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	'''Debugging Notes'''		'''Debugging Notes'''

	1. There are two LEDs on the board. After power-on, D1 blinks indicating the MCU is working properly. D2 stays on when the LVDS signal is received. '''If D2 does not light up, it means no LVDS signal is received - - check the wire sequence.'''		<mark>1.</mark> There are two LEDs on the board. After power-on, D1 blinks indicating the MCU is working properly. D2 stays on when the LVDS signal is received. '''If D2 does not light up, it means no LVDS signal is received - - check the wire sequence.'''

	[[File:LVDS2-07.png\|700px\|On-board LED]]		[[File:LVDS2-07.png\|700px\|On-board LED]]


	2.Before power-on, first confirm if LVDS is single-channel or dual-channel. Normally, 1080P signal is dual-channel, while 720P, 1366x768, 1024x768 and other resolutions are single-channel. For single-channel, short-circuit R20 on the board before powering on. (DIP switch (J1) can be installed for easier debugging.)		<mark>2.</mark> Before power-on, first confirm if LVDS is single-channel or dual-channel. Normally, 1080P signal is dual-channel, while 720P, 1366x768, 1024x768 and other resolutions are single-channel. For single-channel, short-circuit R20 on the board before powering on. (DIP switch (J1) can be installed for easier debugging.)

	[[File:On-board Option Resistors.png\|700px\|On-board Option Resistors]]		[[File:On-board Option Resistors.png\|700px\|On-board Option Resistors]]


	3.If D2 fails to light up and there’s no HDMI output after power-on, the possible causes are:		<mark>3.</mark> If D2 fails to light up and there’s no HDMI output after power-on, the possible causes are:

	(1)Incorrect single/dual-channel configuration (R20);		(1)Incorrect single/dual-channel configuration (R20);
Line 66:		Line 66:


	4.If D2 stays on with stable LVDS signal reception but the monitor still shows a black screen, verify if the monitor supports the current LVDS output resolution. HDMI signals are standard video formats (e.g., 1080P, 720P), and some TVs do not support non-standard resolutions such as 1366x768. In this case, convert the HDMI output to a DVI interface and input the signal via the monitor’s DVI port.		<mark>4.</mark> If D2 stays on with stable LVDS signal reception but the monitor still shows a black screen, verify if the monitor supports the current LVDS output resolution. HDMI signals are standard video formats (e.g., 1080P, 720P), and some TVs do not support non-standard resolutions such as 1366x768. In this case, convert the HDMI output to a DVI interface and input the signal via the monitor’s DVI port.


	5.If D2 flashes on and off, the issue may be caused by an excessive spread spectrum amplitude of the LVDS signal. While this solution supports clock spread spectrum, it has a certain amplitude limit – the LVDS signal cannot be received stably if the limit is exceeded. If the motherboard configuration is modifiable, disable the LVDS signal spread spectrum and retest.		<mark>5.</mark> If D2 flashes on and off, the issue may be caused by an excessive spread spectrum amplitude of the LVDS signal. While this solution supports clock spread spectrum, it has a certain amplitude limit – the LVDS signal cannot be received stably if the limit is exceeded. If the motherboard configuration is modifiable, disable the LVDS signal spread spectrum and retest.


	6.If soldering is needed for testing due to mismatched connectors, differential pairs (+/–) must use twisted pairs, not loose wires.		<mark>6.</mark> If soldering is needed for testing due to mismatched connectors, differential pairs (+/–) must use twisted pairs, not loose wires.


	7.If the cause cannot be identified, connect RX and GND of a USB-to-UART cable (typically CH340G) to TX and GND of CN1 on the board to view debug information, as shown below.		<mark>7.</mark> If the cause cannot be identified, connect RX and GND of a USB-to-UART cable (typically CH340G) to TX and GND of CN1 on the board to view debug information, as shown below.

	[[File:LVDS2-EN.jpg\|700px\|Debug Information]]		[[File:LVDS2-EN.jpg\|700px\|Debug Information]]
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	8.If stable timing is observed via the serial port but still no HDMI output, use a multimeter to check the DC level at the HDMI output port, as shown below:		<mark>8.</mark> If stable timing is observed via the serial port but still no HDMI output, use a multimeter to check the DC level at the HDMI output port, as shown below:

	* If the voltages on the 8 pins of the HDMI connector and the lower end of R31 (refer to the figure) are within the normal range, but the connected monitor still shows no image, the monitor may not support this resolution. TV HDMI ports usually support 720P, 1080P, etc., and do not support graphics card resolutions such as 1024×768 or custom arbitrary resolutions. If the LVDS output resolution is 1024×768 or similar, test with the monitor’s DVI port using an HDMI-to-DVI cable.		* If the voltages on the 8 pins of the HDMI connector and the lower end of R31 (refer to the figure) are within the normal range, but the connected monitor still shows no image, the monitor may not support this resolution. TV HDMI ports usually support 720P, 1080P, etc., and do not support graphics card resolutions such as 1024×768 or custom arbitrary resolutions. If the LVDS output resolution is 1024×768 or similar, test with the monitor’s DVI port using an HDMI-to-DVI cable.