Generally speaking, if a laptop is still in warranty, it may be best to go that route. Keep in mind that your hard drive data will be accessible to the repair personnel. They may also reformat and delete any data on your hard drive when they try to fix the problem. If you go this route, and your data are important to you, you may wish to try removing the hard drive and making a backup of the data on it before sending it in for repair. However, keep in mind that removing the hard drive to make your own backup MAY void the warranty.
If you want to try debugging yourself...
Since the power LED is turning on normally, but other indicators of power-on-sequencing are absent (e.g. "beep codes", Logos, boot-up screens appearing on the screen, HDD activity, and so on), then ONE of the more common causes is mis-seated, contaminated connector, or failed memory card. A memory problem can cause 100% non-functionality of the computer. It can also cause completely
Assuming memory is accessible to the user (some laptops don't provide easy access)...
Important! For ALL handling of computer electronic components and when the case of the computer is "open", see Note1.
One of the easier and quickest tests for the relatively non-technical Home user is to try re-seating the memory card(s), cleaning the connectorsNote2
, "swapping" cards (if more than 1), or replacing with a borrowed card (that meets the specs required for the laptop (GB capacity, physical form-factor and size, number of pins, speed, etc). If two cards are installed, remove the NON-primary card (see user manual to ID the primary or "first" card) and try to re-boot. If that doesn't resolve the issue, remove the "primary" card and try re-booting with the other card installed in the PRIMARY card slot
(still just using 1 card).
There are threads on HWA and other fora that discuss diagnosing laptop memory and laptop "won't boot-up" problems in more detail.
(To diagnose the problem, it MAY
even be economically worth it to buy one of the cheaper memory cards (e.g. a 2GB "slow" card instead of a 4GB "faster" card) to conduct the test. A cheaper card is suggested because it may still fail or the card may be damaged during the test. Obviously that decision depends on the finances of and whether the laptop is still in warranty and the technical experience of the user. (and of course the new memory card must meet the specs required for the laptop))
it is possible the replacment memory card may be damaged by this test. Generally speaking that's not likely...but it IS possible.
However, if there is non-removable memory in the laptop, then there is no way for the home user to test if a failure in that base memory is the cause. In such cases, IF there is a removable memory card then re-seating, removing completely, and/or replacing it may or may not resolve the problem.
There are additional actions a user can take to diagnose this, but they are usually beyond the scope of a typical home user.
ESD and Power While Debugging/Testing Components
be sure to follow all power-off AND
disconnected, battery removal, etc. and handling requirements (e.g. Electro-Static-Discharge (ESD) protocols) before and while removing and replacing parts in a computer, and/or when the computer case is "open". These are usually detailed in the user manual and in replacement part kits. If power and ESD protocols are not followed 100% the computer or components, may be damaged. Such damage may be immediate, catastrophic, and easily seen (e.g. massively corrupted hard drive causing boot or run-time failures), or latent and difficult to discover (e.g. lost/corrupted data in one or more files, intermittent and random "problems", etc).
First, look at both the card and the computer's memory slot connectors for obvious contamination. To clean connectors on the card
you can use a lint-free cloth or high-quality cotton swab lightly dampened (not soaked) with medical alcohol (alcohol and water ONLY and preferably 90-99% alcohol). Wait til 100% dry. Check for remaining particles, residue, etc after cleaning. Do not
"blow" on it to dry it or remove particles. For the connector in the computer, use a canned-"air"-for-electronics as instructed on product. I recommend using one that uses purified air only...not a refrigerant or anything with a "bittering agent". Do not
use an abrasive eraser or any sandpaper/burnishing-cloth as that can remove the very
thin gold-plating on the connectors...which will lead to corrosion later...which may lead to unpredictable problems including data-loss. Important Note: the gold plating on some connectors/cards may be damaged by as few as 20 insert/removal cycles. It depends on the designers and manufacturing processes. Thinner and more fragile plating is coming into products as cost-cutting is accelerated throughout the industry, and a memory card is usually considered to be a component that is not frequently installed/removed, tempting more manufacturers to use thinner plating to reduce costs.
minor clarifications, expand Note1 to reinforce importance of following power and ESD protocols, and add Note2 details re cleaning connectors