我最近在我的 HTPC 上从 Unity 切换到 Xfce，并全新安装了 Xubuntu。
现在，每当我关掉电视并让它静置一会儿，当我重新打开电视时，就没有视频信号，即使输入键盘/鼠标也没有信号。（实际上，我在运行 Debian 上的 Xfce 的笔记本电脑上也遇到了同样的问题）。操作系统正在接收我的输入，但显示器/电视始终收不到任何信号。
我已阅读并尝试了许多类似问题的解决方案，但与我的问题完全相同的问题似乎并未得到解决。
到目前为止，我唯一能做的就是远程重启 lightdm（如果这是我唯一的解决方案，我可能可以将其设置为键盘快捷键）但这不是真正的解决方案。
关于我的 HTPC
操作系统：
$ cat /etc/*-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.3 LTS"
NAME="Ubuntu"
VERSION="14.04.3 LTS, Trusty Tahr"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 14.04.3 LTS"
VERSION_ID="14.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
硬件：
$ lspci
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Root Complex
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Kabini [Radeon HD 8400]
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Device 9840
00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 0
00:02.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:02.4 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:02.5 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Functions 5:1
00:10.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller (rev 01)
00:11.0 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] (rev 40)
00:12.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 39)
00:12.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 39)
00:13.0 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB OHCI Controller (rev 39)
00:13.2 USB controller: Advanced Micro Devices, Inc. [AMD] FCH USB EHCI Controller (rev 39)
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 3a)
00:14.2 Audio device: Advanced Micro Devices, Inc. [AMD] FCH Azalia Controller (rev 02)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 11)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 0
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 16h Processor Function 5
01:00.0 Audio device: Creative Labs Device 0012 (rev 01)
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 11)
03:00.0 USB controller: ASMedia Technology Inc. Device 1142
$ lspci -vnn | grep VGA -A 10
00:01.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Kabini [Radeon HD 8400] [1002:9830] (prog-if 00 [VGA controller])
Subsystem: ASUSTeK Computer Inc. Device [1043:8623]
Flags: bus master, fast devsel, latency 0, IRQ 42
Memory at c0000000 (64-bit, prefetchable) [size=256M]
Memory at d0000000 (64-bit, prefetchable) [size=8M]
I/O ports at f000 [size=256]
Memory at feb00000 (32-bit, non-prefetchable) [size=256K]
Expansion ROM at feb40000 [disabled] [size=128K]
Capabilities: <access denied>
Kernel driver in use: radeon
电视通过 HDMI 连接。
我在笔记本电脑上卸载了 xfce4-power-manager 和 light-locker，所以现在它从不休眠，显示器始终处于打开状态。这对电池/电费来说很严重，但至少当我离开几分钟时，我打开的内容不会丢失。
在 HTPC 上我现在可以将它们删除，但我不喜欢没有电源管理，我是否应该尝试使用 gnome-screensaver 和 gnome-power-manager？