Troubleshooting 4
S-Series Oscilloscopes Service Guide 65
 
Display Troubleshooting
When you connect an external monitor the first time, it may display the start-up BIOS 
information and then go blank when Windows starts up. If so, use the Windows settings to 
enable the external monitor.
Connect external 
monitor to VGA 
port. Turn on power.
Does display 
appear on ext. 
monitor?
Is front panel 
display 
scrambled?
Is front panel 
display black?
Check LED backlight cable, 
front panel power cable, and 
backlight enable connector
Still black?
Replace keyboard 
assembly rear board
Still black?
Replace LCD Still black?
Done. Go to 
“Primary Trouble 
Isolation”
No
Yes
No
Yes
Yes
Replace 
motherboard
Replace 
motherboard
Yes
No
Yes
Check display cable 
connection to 
monitor
Yes
Still scrambled?
Replace 
motherboard
Yes
No
No