The RAM might be bad and if the old RAM still works, you might already have the culprit.
Tried reseating the RAM? Tried placing the largest stick of RAM in the number 1 slot and all other sticks in the remaining slots?
Most importantly, since you've given us NO information about your computer, does it support the extra 512 MB? Older Windows 98 machines and such may not support the amount you've given it.
Hope this helps.
Grif
I added 512 DDR samsung ram to my computer, and now it won't turn on. Iv added ram before and never had this kind of issue. Any ideas

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