升级台式机，运行 AMD A10-7870K 和 Gigabyte F2A88XM-D3H 主板。从 Ubuntu 14.04LTS 升级到 16.04。重启后显示器显示 bios 但随后变为空白。没有 Ubuntu 登录页面。通过重置按钮重启电脑。同样的事情发生了。再次重启并按住 shift 按钮。没有变化。注意到硬盘灯亮了。尝试盲目登录。硬盘灯亮了一段时间。可以从笔记本电脑 ping 桌面。这个台式机升级后会出现显示问题吗？有什么想法吗？
更新：重新启动电脑并可以听到 Ubuntu 启动声音。
更新：将电脑插入 HDMI 并登录时获取图片。登录并有桌面。更新后 VGA 不工作？
VGA 输出仅适用于连接 HDMI
这是部分启动日志。我看到的错误和 Radeon 信息。
[ 3.254386] [drm] Radeon Display Connectors
[ 3.254389] [drm] Connector 0:
[ 3.254390] [drm] DVI-D-1
[ 3.254392] [drm] HPD3
[ 3.254393] [drm] DDC: 0x6550 0x6550 0x6554 0x6554 0x6558 0x6558 0x655c 0x655c
[ 3.254394] [drm] Encoders:
[ 3.254396] [drm] DFP2: INTERNAL_UNIPHY2
[ 3.254397] [drm] Connector 1:
[ 3.254397] [drm] HDMI-A-1
[ 3.254398] [drm] HPD1
[ 3.254400] [drm] DDC: 0x6530 0x6530 0x6534 0x6534 0x6538 0x6538 0x653c 0x653c
[ 3.254400] [drm] Encoders:
[ 3.254401] [drm] DFP1: INTERNAL_UNIPHY
[ 3.254402] [drm] Connector 2:
[ 3.254403] [drm] VGA-1
[ 3.254404] [drm] HPD2
[ 3.254405] [drm] DDC: 0x6540 0x6540 0x6544 0x6544 0x6548 0x6548 0x654c 0x654c
[ 3.254406] [drm] Encoders:
[ 3.254407] [drm] CRT1: INTERNAL_UNIPHY3
[ 3.254408] [drm] CRT1: NUTMEG
[ 3.489293] [drm] fb mappable at 0xC0728000
[ 3.489296] [drm] vram apper at 0xC0000000
[ 3.489298] [drm] size 8294400
[ 3.489299] [drm] fb depth is 24
[ 3.489300] [drm] pitch is 7680
[ 3.489675] fbcon: radeondrmfb (fb0) is primary device
[ 3.489759] Console: switching to colour frame buffer device 160x64
[ 3.489786] radeon 0000:00:01.0: fb0: radeondrmfb frame buffer device
[ 3.516759] ACPI Error: [\_SB_.ALIB] Namespace lookup failure, AE_NOT_FOUND (20150930/psargs-359)
[ 3.516767] ACPI Error: Method parse/execution failed [\_SB.PCI0.VGA.ATC0] (Node ffff88042f0c41e0), AE_NOT_FOUND (20150930/psparse-542)
[ 3.516775] ACPI Error: Method parse/execution failed [\_SB.PCI0.VGA.ATCS] (Node ffff88042f0c41b8), AE_NOT_FOUND (20150930/psparse-542)
[ 3.523294] kfd kfd: Allocated 3944480 bytes on gart for device(1002:130f)
[ 3.523312] kfd kfd: error getting iommu info. is the iommu enabled?
[ 3.523315] kfd kfd: Error initializing iommuv2 for device (1002:130f)
[ 3.523338] Creating topology SYSFS entries
[ 3.523421] kfd kfd: device (1002:130f) NOT added due to errors
[ 3.523425] [drm] Initialized radeon 2.43.0 20080528 for 0000:00:01.0 on minor 0
[ 5.231796] [drm:radeon_dp_link_train [radeon]] *ERROR* clock recovery reached max voltage
[ 5.231862] [drm:radeon_dp_link_train [radeon]] *ERROR* clock recovery failed
答案1
如果您有 AMD APU 或 Gigabyte 主板。不要升级到 16.04lts。我的 VGA 端口只能与连接到另一台显示器的 HDMI 端口配合使用。最后用 14.04lts 重新加载。一切正常。发现显卡驱动程序出了问题。我的旧笔记本电脑，基于英特尔的系统运行良好。也许是 Radeon 驱动程序？这只是我的个人经验。
答案2
从 grub 启动时关闭 nomodeset。