Well the intermittent LCD screen flicker on the 1545 is a known issue.
Try attaching an external monitor and see if you still get the flicker.
This is a mid-price laptop, but the quality of construction is a disappointment.
I used to like some Dell laptop models for fair quality at a fair price.
But I am seeing many complaints on forums and reviews in the last 18 months, especially for the budget and midrange price models.
You can view or download the [http://support.dell.com/support/edocs/systems/ins1545/en/index.htm|service manual free from Dell here] -- note that is in web page format, not PDF, so if you download it, be sure to unzip it into a new empty folder. Otherwise you'll have web page parts scattered all over your desktop.
Disassembly is not very difficult, but in my experience it is not likely to result in a repair. You will probably '''not''' find a loose wire or crimped cable, or any obvious fault. Best of luck, and start saving for a Compaq, HP or Apple.