Dell Latitude D620 won't power on

Hello! I have a Dell Latitude D620 that runs Windows 7 and is 8 years old. Through the years I have replaced various parts on the laptop including the memory, the motherboard, and some other stuff (I'm no techie). Over the past two years or so, my laptop screen has went black when I've jiggled the cord somehow. Also, the three lights would go out, (one is power, one is the brain, one is battery, last is wifi) and every light EXCEPT the power light would go out. I would turn it off, then back on and things would be fine.

I have run a couple of tests which suggested my computer was going bad. It can't pass the short (can't think of the name) test. Still, it's been working just fine for more than 2 years. I back up every Friday, so I'm prepared if it is toast.

Recently I jiggled the cord and all was lost. I assumed my problem was with the adapter b/c I could still power on with the battery. I purchased 3 new cords (two knockoffs from Amazon, one expensive one from Dell directly) and none will work. The adapter light comes on when it is plugged up and stays on when my laptop is connected. However, none will power on my laptop or charge the battery. When I try to power on with or w/o the power cord, the battery light blinks red and nothing else happens.

I would like to know what I can do. I tried the GeekSquad, but those folks were pushing me to get another computer instead. I have other laptops. A Dell Inspiron and a Macbook. But, this laptop is my baby. I love it! It was the first one I ever purchased and I even named it. It is the one I use everyday at work and the one that got me through school.

I appreciate any help you might be able to send my way! I'm also happy to provide any additional information you might need.

 

One short test is the short S.M.A.R.T. test of the hard drive. Another is the short test of the RAM. Failing either of these short tests indicates problems with either the hard drive or the RAM. Do you get "beep codes" when the system fails and what are they (ie. 3 short, 1 long and 2 short)? The codes will direct someone to the source(s) of the problem(s).

 

Thank you for the quick reply! I ran the tests about a year ago and honestly can't remember whether they were short beeps or long beeps. If this helps--I remember using both Dell's diagnostic disc (I still have it if you need more info) and a few pieces of software that I downloaded from this site (can't remember names). I can't run the test again b/c I'm unable to power the laptop at all.

About 6 months ago, I also had some BSD that were completely jumbled nothingness. Just a blue screen with white lines that weren't actual letters or characters of any sort. Also, sometimes the sound will work and sometimes it won't. There's no rhyme or reason to it. Wifi always works. All my documents are where they should be and I've not had trouble saving anything. I blew it off because my laptop would end up working great again. I also never heard any of the so called clicking sounds that go along with laptop failure. I did have an awesome warranty for years, but that has long since passed. During that time, I had just about everything replaced. I'm hopping it's not dead yet, or that it can be resurrected somehow.

Also, I've tried removing the battery to get it to power on and that won't work either. I have changed electrical outlets and that was not help as well. I just want the poor thing to turn on.

I hope I'm providing enough information. I really appreciate the help!