Real-Time Clock (Rtc Reset) - Dell Latitude 7420 Service Manual
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Also See for Latitude 7420:
- Service manual (85 pages) ,
- Setup and specifications (26 pages) ,
- Setup and specifications manual (26 pages)
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Table 19. Diagnostic LED behavior (continued)
Blinking pattern
Amber
2
2
2
2
2
3
3
3
3
3
3
3
NOTE:
Blinking 3-3-3 LEDs on Lock LED (Caps-Lock or Nums-Lock), Power button LED (without Fingerprint reader), and
Diagnostic LED indicates failure to provide input during LCD panel test on Dell SupportAssist Pre-boot System Performance
Check diagnostics.
Real-Time Clock (RTC Reset)
The Real Time Clock (RTC) reset function allows you or the service technician to recover Dell Latitude, systems from No
POST/No Power/No Boot situations. The legacy jumper enabled RTC reset has been retired on these models.
Start the RTC reset with the system powered off and connected to AC power. Press and hold the power button for thirty (30)
seconds. The system RTC Reset occurs after you release the power button.
80
Troubleshooting
White
Problem description
4
Memory/RAM failure
5
Invalid memory installed
6
System board/Chipset Error
7
LCD failure (SBIOS message)
8
LCD failure (EC detection of
1
CMOS battery failure
2
PCI or Video card/chip failure
3
BIOS Recovery image not
4
BIOS Recovery image found
5
6
Flash corruption detected by
7
Timeout waiting on ME to
reply to HECI message.
power rail failure)
found
but invalid
Power rail failure
SBIOS.
Suggested resolution
●
Reset and swap memory
modules amongst the
slots.
●
If problem persists,
replace the memory
module.
●
Reset and swap memory
modules amongst the
slots.
●
If problem persists,
replace the memory
module.
Replace the system board.
Replace the LCD module.
Replace the system board.
●
Reset the CMOS battery
connection.
●
If problem persists,
replace the RTS battery.
Replace the system board.
●
Flash latest BIOS version
●
If problem persists,
replace the system board.
●
Flash latest BIOS version
●
If problem persists,
replace the system board.
Replace the system board.
Replace the system board.
Replace the system board.
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