Agilent Technologies 45A, 46A, 54835A manual Troubleshooting, No Display Trouble Isolation, Power-on

Chapter 5: Troubleshooting

No Display Trouble Isolation

Table 5-1

Power-On Sequence with External Monitor Connected

Time	Audible Indicators	Visible Indicators	Description	Troubleshooting
1	Power-on		Power-on the instrument and listen
			for the fans and the hard disk drive.
			The hard disk is located behind the
			floppy drive against the chassis side
			wall.
2	Fans begin running	Power switch LED illuminates	The main instrument fan and the	You will need to use a DMM to
			CPU fan start running at power on.	verify that the supply voltages
			The LED located behind the front	are within specifications. If the
			panel power switch is connected to	power supplies do not come up,
			the +5 V supply, making it a good	go to the “Power Supply Trouble
			power supply indicator.	Isolation” flowchart
3	HDD (hard disk drive)	Front panel LEDs come up in	The front panel LEDs display their	If the LEDs do not come on,
	begins turning	power-on pattern	power-up pattern. The following	check the cabling to the front
			trigger LEDs should all come on at	panel board and check for +5 V
			the same time: Edge, Glitch,	on pin 2 of the 10-pin conductor
			Advanced, Positive and Negative	keyboard cable W16. Also check
			slope, DC, AC, LF Reject, and HF	for +5 V on the scope interface
			Reject. This pattern indicates that	card A6. If the +5 V is at the scope
			the front panel keyboard has	interface card but the front panel
			completed its power-on test.	LEDs do not come on, the
				problem is the cable or the front
				panel keyboard A7.
			The hard disk drive (HDD) starts	If the HDD is not responding,
			spinning at power on. Listen at the	check the cabling. If the disk is
			top right rear of the instrument for a	turning, but you do not hear the
			higher-pitched whine; this is the	brief burst of clicks after the disk
			HDD coming up to speed. Shortly	comes up to speed, the circuitry
			after the disk comes up to speed,	onboard the disk drive may be at
			you should hear a brief burst of	fault. If the motherboard
			clicks*; this sound is part of the	(including CPU and RAM) are
			disk's power-up self-check routine.	functioning but the HDD is not
				responding, the external VGA
				monitor will usually show the
				message "16000 KB OK, WAIT..."
				followed by the message "Pri
				Master HDD Error, RUN SETUP,
				Press F1 to Resume. See “To
				configure the motherboard
				jumpers and set up the BIOS” on
				page 5-29.for information on
				how to access and run the setup
				program. If, after running setup,
				there is still a problem, check the
				cabling for the hard disk drive,
				both between the motherboard
				and SVGA display board, and
				between the SVGA display board
				and the HDD. If the cabling is OK,
				see the section on verifying
				motherboard operation;
				otherwise, replace the HDD.

* 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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