more often than not, the white screen issue is not "hardware" based. It may be, but try a from "firmware" rebuild and see if that helps. No guarantees but if you have already tried everything else I would suggest it as my wife's was having this issue and it seems to have solved the issue. That being said, I did change out my wife's battery and after a few "don't use the 3g parts on 3gs!" mishaps the firmware rebuild was the one thing that resolved the last (white screen) issue. Only use this as a solution of last resort, but it worked for me. Many iphone issues on the 3gs have a "white screen" symptom but 3 or 4 times a rebuild from saved firmware fixed the issue.
had this a few times myself. make sure the fan connector did not come out of it's socket and that the socket itself is sitting flush and that both pins are making their way through the socket and into the fan connector. common issue with the D series.
The battery is not charging from your description. 1. power off, remove battery and put on charger and then try again. battery shorts are common on the D620. 2. try another power adapter as the power adapters have a pretty high failure rate on the D series Latitude laptops (I have over 120 of them at my office, they are not very reliable and have many issues) 3. check and clean battery and power contacts 4. check power connectors to mb and to batt update if these do not work
NO! this will cause your iphone to start doing a non stop reboot to the apple screen until it kills the battery. I just did this to my wife's phone after successfully replacing my own with a proper 3gs battery. Let me tell you, I am really in the dog house now... going to replace with a proper 3gs battery and see if it works...