I should add I don't get any beep codes or anything.

I replaced the LCD cable a few months ago because it frayed and shorted out and burned my mobo. I replaced the mobo along with the cable but it still didn't output anything to the display not even backlight. I took it to a professional shop and they told me to replace the cable again which i just did. Now I have backlight. Before today I have used the computer on my HDTV and it worked fine. Today it won't boot. The machine is out of warranty :(

I have run some more tests. I did the display test holding the D key and the display showed lots of pretty colors. I did the hardware diagnosis holding fn when powering up and I waited a few minutes and it made a lot of musical beeps repeatedly but I couldn't see anything still. I plugged into my tv via hdmi and nothing came out.

Hi lappingluke,

The connection between the LCD and motherboard appears to be broken. It appears to be an issue either with LCD cable or with the motherboard. If the system is under warranty, you can private message me the service tag of computer. I have added you as a friend. Please accept my friend request by clicking on my name highlighted in blue and then click on “Friends” tab at the top and then click on “Request to Review” and finally click on “Accept” button.

I am sending you a private message as well. Click on “Inbox” to respond to the message and provide system’s Service Tag and contact details so I may access your system records and check for further course of action. You could also click on Start Conversation to send a private message.

If the system is out of warranty, i would recommend you to change the LCD cable first. LCD cable is not a customer replaceable unit. If you are comfortable, you can try replacing it. You can find detailed information on replacing the cable from link:

ftp://ftp.dell.com/Manuals/all-products/esuprt_laptop/esuprt_inspiron_laptop/inspiron-15-intel-n5010_service%20manual_en-us.pdf 

Copy and paste the above link in address bar of browser and hit Enter. 

Note: Please ensure to follow the safety instructions in manual.

If the issue persists, it might be issue with motherboard and need replacement.

Please reply with information. 

And if I power up and let it sit, it'll happily sit there and do nothing but after a minute or so it will give up and power off. The ac adaptor is plugged in and the power light is white as well as the charging light.

The problem does not appear to be related to the display. The machine does not boot. Should I remove the CMOS battery to force it to reset or could I lose my BIOS totally?

Hi lappingluke,

I appreciate your efforts. 

As the LCD built in test has passed, LCD of your computer has no issues. You can try re-seating or replacing the CMOS/Coin cell battery of your computer and see if it makes any difference. Coin cell battery is not a customer replaceable unit.  If you are comfortable replacing it on your own, you can check detailed instructions from the service manual given in previous post. Please ensure to follow the safety instructions mentioned in manual.

If the issue persists after replacing/re-seating CMOS battery, it might be an issue with motherboard and might need replacement. 

Please reply for further clarifications. 

Using it*

I'll try reseating the battery. Don't forget my motherboard is new I hope it didn't randomly go sour while I wasn't using i.

I reseated the CMOS coin battery and now I get a 5 beep POST code.