记录树莓派连接显示器异常的解决办法

前不久入手了一块树莓派，在连接显示器时，画面断断续续，完全无法使用。

网上搜索了很多资料和教程，发现状况都跟自己遇到的不太一样，遂抹掉SD卡上原本带的系统，重装了最新版的Raspberry Pi OS（32bit）。

之后信心满满的连接显示器，上电后在命令行界面显示正常，在图形界面显示器显示无信号输入。由于屏幕和HDMI线都是新购的，所以首先怀疑是不是这两件出现问题。在其他电脑上测试后，很快排除了该原因。

网上的资料提示有可能是pi的配置文件问题。于是在MicroSD卡中找到config.txt文件，进行了多次尝试，最终确定了文件对于该显示的的正确配置：

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# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
hdmi_safe=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
hdmi_group=2
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on

# Uncomment this to enable infrared communication.
#dtoverlay=gpio-ir,gpio_pin=17
#dtoverlay=gpio-ir-tx,gpio_pin=18

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
dtparam=audio=on

# Automatically load overlays for detected cameras
camera_auto_detect=1

# Automatically load overlays for detected DSI displays
display_auto_detect=1

# Enable DRM VC4 V3D driver
dtoverlay=vc4-kms-v3d
max_framebuffers=2

# Disable compensation for displays with overscan
disable_overscan=1

[cm4]
# Enable host mode on the 2711 built-in XHCI USB controller.
# This line should be removed if the legacy DWC2 controller is required
# (e.g. for USB device mode) or if USB support is not required.
otg_mode=1

[all]

[pi4]
# Run as fast as firmware / board allows
arm_boost=1

[all]

相较于默认文件，主要修改部分为：

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#取消hdmi_safe模式的注释
hdmi_safe=1
#取消hdmi热插拔模式的注释
hdmi_force_hotplug=1
#取消hdmi_group注释并将指修改为2，含义大概是较新显示器，老显示器可能要使用1
hdmi_group=2
#取消注释
hdmi_drive=2
#取消config_hdmi_boost注释增强hdmi信号
config_hdmi_boost=4

然后就可以愉快的点亮屏幕啦