Agilent Technologies 46A Or RAM, the Svga display, Show the memory test, Power to the instrument

Chapter 5: Troubleshooting

No Display Trouble Isolation

Time	Audible Indicators	Visible Indicators	Description	Troubleshooting
4	HDD clicking*	PC Power-On Self Test	The HDD begins clicking* as it is	If there is no display on the
		(POST) memory test message	accessed by the system. The	external monitor, either the
		on external monitor.	external SVGA monitor shows the	motherboard A4 (including CPU
			POST messages. These messages	or RAM), the SVGA display
			show the memory test.	board, cabling, or external VGA
				monitor are suspect. Check the
				cabling and VGA monitor first.
				Next, use a POST (Power-On Self
				Test) card to help isolate the no-
				display problem. Install the POST
				card in an ISA slot and apply
				power to the instrument. The
				POST card displays the
				respective codes as the power-
				on self tests are completed. See
				the “POST Code Listing” in this
				chapter for codes and
				descriptions. Replace the
				motherboard, CPU, or RAM as
				indicated from the POST code
				listing.
5	HDD clicking*	System board configuration	The HDD continues clicking* as the
		appears on external monitor	instrument loads the oscilloscope
		and internal display.	application. The flat panel LCD
			backlight comes on and the display
			shows the system board
			configuration. This is an indication
			that the motherboard and SVGA
			display board are functioning
			correctly.
6	HDD clicking*	The Infiniium display appears	The HDD continues clicking.*
		on the internal and external
		displays.
7	Attenuators click as	Front panel LEDs change to a	The attenuators click. This is louder
	solenoids are preset	normal operating pattern.	than the HDD clicking and comes
	to known states	Both screens go blank	from the front of the instrument. The
		momentarily.	front panel LEDs change to a normal
			operating pattern. For example, the
			Trigger LEDs show only one trigger
			mode, such as Edge, and one trigger
			coupling, such as dc.
8	Attenuators click to	Oscilloscope display comes	The attenuators click a second time.	If the attenuators click a second
	their operating states	up on both the external	The oscilloscope display backlight	time but the display does not
	(second interval,	monitor and the scope's front	comes on, and the display appears	come up, try the front panel keys
	indicates scope	panel display.	on both the external monitor and the	to see whether they respond. If
	running)		scope's front panel display. The	so, there is a display problem. If
			oscilloscope is running.	the external monitor shows the
				screen but the oscilloscope does
				not, the problem may be with
				cabling, the backlight inverter
				board A3 not supplying +900 V
				and +12 V, the flat-panel display
				A2, or the SVGA display board
				A5. See the sections “To check
				the backlight inverter voltages”
				and ”To check the SVGA display
				board video signals.”

* Later model hard disk drives are much quieter than earlier models.

The clicking can only be heard with the instrument sleeve removed and in close proximity to the hard disk drive.

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