In certain new opening, about one week after whole machine is installed, start machine and find out TV has no image, connect monitor and keyboard and find out each function single board initiate normally. Restart the machine, malfunction stay the same. Sometimes, host machine initiate and give off the beep sound when host machine starting. Monitor shows no image. It can succeed once after many times. The rate of successful startup is quite little.
Power up and give off beep- beepbeep-beep alarm. The communication of front and back stage is normal.
The beep- beepbeep-beep alarm when the host start means host BIOS didn’t find display adapter. We doubt it’s because the bad contact of video adapter and host slot. Change the position of display adapter. Malfunction remains.
2. When host machine start normally, though each single board initializes normally, but still has not image output. Through exam, the camera has image sent into the terminal.
3. switch the display adapter to Lenovo host backstage. Test power on and off 20 times. Monitor is normal. It means the display adapter has no malfunction.
4. We doubt the host power source load is not enough. Unplug all single board, leave only the display adapter, machine can successfully start. Add single board, in turn. When adding MUX board, the host can’t start. After we replace it ,the problem solved.
In this case, the host can’t find monitor when it initialize, and can’t successfully start. We doubt the monitor may be broken. In fact, the reason is VC02MUX board circuit is malfunction, causing host can’t find video adapter, and initialization fail.