HP Compaq dc7800 User Manual

Power LED flashes Red four times, once every second, followed by a two second pause, and the computer beeps four
times. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause
Solution
Power failure (power supply is overloaded). 1. Check that the voltage selector, located on the rear of the
power supply (some models), is set to the appropriate
voltage. Proper voltage setting depends on your region.
2. Open the hood and ensure the 4- or 6-wire power supply
cable is seated into the connector on the system board.
3. Check if a device is causing the problem by removing ALL
attached devices (such as hard, diskette, or optical
drives, and expansion cards). Power on the system. If the
system enters the POST, then power off and replace one
device at a time and repeat this procedure until failure
occurs. Replace the device that is causing the failure.
Continue adding devices one at a time to ensure all
devices are functioning properly.
4. Replace the power supply.
5. Replace the system board.
The incorrect external power supply adapter is being used on
the USDT.
The USDT power supply adapter must be at 135W and use the
Smart ID technology before the system will power up. Replace
the power supply adapter with the HP-supplied USDT power
supply adapter.
Solving Diskette Problems
Common causes and solutions for diskette problems are listed in the following table.
NOTE: You may need to reconfigure the computer when you add or remove hardware, such as an
additional diskette drive. See
Solving Hardware Installation Problems on page 237 for instructions.
Table D-3 Solving Diskette Problems
Diskette drive light stays on.
Cause
Solution
Diskette is damaged. In Microsoft Windows XP, right-click Start, click Explore, and
select a drive. Select File > Properties > Tools. Under Error-
checking click Check Now.
In Microsoft Windows Vista, right-click Start, click Explore,
and right-click on a drive. Select Properties then select the
Tools tab. Under Error-checking click Check Now.
Diskette is incorrectly inserted. Remove diskette and reinsert.
Drive cable is not properly connected. Reconnect drive cable. Ensure that all four pins on the diskette
power cable are connected to the drive.
Table D-2 Solving Power Problems (continued)
Solving Diskette Problems 223

HP Compaq dc7800 Specifications

General

Tcase	73.3 °C
Bus type	FSB
Stepping	M0
Processor cache	2 MB
Processor cores	2
Processor model	E4600
System bus rate	- GT/s
Processor family	Intel® Core™2 Duo
Processor series	Intel Core 2 Duo E4000 Series
Processor socket	LGA 775 (Socket T)
Processor codename	Conroe
Processing Die size	111 mm²
Processor frequency	2.4 GHz
Processor cache type	L2
Processor lithography	65 nm
Processor manufacturer	Intel
Processor front side bus	800 MHz
Processor operating modes	64-bit
ECC supported by processor	No
Thermal Design Power (TDP)	65 W
CPU multiplier (bus/core ratio)	12
Number of Processing Die Transistors	167 M
Internal memory	1 GB
Internal memory type	DDR2-SDRAM
Maximum internal memory	8 GB
Memory layout (slots x size)	2 x 0.5 GB
HDD speed	7200 RPM
HDD interface	SATA
Optical drive type	DVD Super Multi
Total storage capacity	160 GB
Audio input	1
LightScribe	Yes
Networking features	Intel 82566DM Gigabit Network Connection
Graphics card RAMDAC	400 MHz
Storage drive controller	SATA 3, 0 Gb/s NCQ SMART VI
Discrete graphics card model	Intel® GMA 3100
Maximum graphics card memory	0.256 GB
Operating system installed	Windows Vista Business
USB 2.0 ports quantity	8
Chassis type	Mini Tower
Country of origin	China
Cable lock slot type	Kensington
Operating altitude	0 - 3048 m
Non-operating altitude	0 - 9144 m
Storage temperature (T-T)	-30 - 60 °C
Operating temperature (T-T)	10 - 35 °C
Storage relative humidity (H-H)	5 - 95 %
Operating relative humidity (H-H)	10 - 90 %
Power supply	365 W
Product type	PC
Processor code	SLA94
Processor ARK ID	32242
Processor package size	37.5 x 37.5 mm

Weight and Dimensions

Depth	452 mm
Width	177 mm
Height	447 mm
Weight	11800 g