Dell XPS 420 1,2,3 light, no boot.

Classico79

Honorable
Jan 14, 2013
4
0
10,510
Hello, hoping I can get some information or a helpful push in the right direction.

Dreaded 1,2,3 indicator lights on Top Bezel. At first was pretty sure it was a faulty i/o front panel since the one of the usb ports had a pin bent and the black plastic somehow snapped off. Found one on Ebay for 17 bucks and installed.

Well, intially I had a blinking amber light. Read some stuff and did some research and some guy had a similar situation and had found it to be the i/o. Figured mien was broken anyways and might as well replace. Did so and now the front power indicator doesn't light at all lol.

Computer will only run fans and drives when I disconnect the i/o grey connector. Did it from both ends, motherboard and front panel. Currently its disconnected from front panel i/o only. When grey connecter is connected at both ends computer turns on for a second then sputs out with 10 seconds. Cannot get keyboard or mouse to activate monitor, it will not detect so it goes to black. This is whether th ei/o connector is plugged in or not. Unplugged the computer starts up but I have no video


I replaced the power supply three years ago years ago(650-700 anatech) along with a video card three years ago(gts 260). Replaced hard drive two years ago. Is this avideo card issue, hard drive? Perhaps the new i/o is faulty as well? Hoping not a motherboard issue. When I get home I'm going to reseat the video card, and even unplug it and see what happens, but a little frustrated. Does anyone have any direction on the matter they could give?

I would appreciate it very much
 

Classico79

Honorable
Jan 14, 2013
4
0
10,510


Actually resetting the memory and video card got the display to work. So I now can access bios and anything else. When I plug in the grey connector though the comp will start and sputter still. Only will startup with the i/o front panel disconnected. I already replaced the stupid thing so I'm not understanding what the deal is.

I get a black screen that says alert! Air temperature sensor not detected. Front panel not detected. Anybody familiar with this juncture?
 

Classico79

Honorable
Jan 14, 2013
4
0
10,510



Thanks Friedman, I've narrowed it down to the actual grey ribbon connector, think it's bad. Gonna switch that out and see what happens. Thanks for all your help :sol:
 
If the ribbon cable swap doesn't work (hopefully it will), you can check your CMOS battery. On Dell machines I found that the CMOS battery going bad can do strange things to the system. On most computers the first indication of a bad CMOS battery is the requirement to Set System Clock on startup - Dells just do funky things, usually without that notice.