Q: 2006 Macbook screen stays black, machine beeps 3 times, and sleep light blinks 3 times before repeating when powered on

Three beeps usually means faulty ram...this article explains how to remove/install memory in various models.  You might try removing the memory modules, then insert each and see if it will start with all or if one is faulty.

Acording to MacTracker your MB uses 200-pin PC2-5300 (667MHz) DDR2 SO-DIMMs.

You can get warranted RAM from several sources, but stay away from eBay and Amazon - you've no guarantee what you're getting there.

Most used vendors for Macs are Crucial and OWC (MacSales).

Just enter your details in the chooser and see what's avaialble.

Crucial will scan your MB for you to get the exact right modules if you allow them. (perfectly safe).

Crucial generally stick with Apple's certified maximum (4GB in your case).

OWC do their own testing and will offer a bigger kit if it's known to work (in your case 6GB)

Don't use ValueRAM if you go to another vendor - stick with premium lines.

According to the Everymac site, http://www.everymac.com that MacBook takes PC2-5300 DDR2 667 MHz ram, which Apple says can be up to 4 GB, but some suppliers such as Crucial and OWC say can be as much as 6 GB.  If you want to replace the ram, both of those sites are Mac specialists and will provide guaranteed high quality, Mac compatible memory modules.

If you have an Apple store/genius bar accessible it might be worth your time to take the MacBook in and have the techs run some diagnostics just to be sure the fault is in the memory modules and that there isn't an additional problem before you invest in new memory.

Yes, and you can get more specific going to the apple in the upper left of the menu bar, About This Mac, More Info, System Report, and look at the info under hardware...will have Mac and a number which indicates the machine type, such as 2,1 or some thing like that.

Try these.

http://www.crucial.com/uk/store/listparts.aspx?model=MacBook%202.4GHz%20Intel%20 Core%202%20Duo%20%2813-inch%20White%29&Cat=RAM

http://eshop.macsales.com/MyOWC/Upgrades.cfm?sort=pop&model=294&type=Memory

If in doubt, give them a call - you'll find either of them very helpful.

Sorry, that Crucial link was for the UK store - here's the US one -

http://www.crucial.com/store/listparts.aspx?model=MacBook%202.4GHz%20Intel%20Cor e%202%20Duo%20%2813-inch%20White%29&Cat=RAM

Hey, try newegg. I found that my ram was much cheaper on newegg than most other sites. You can usually read reviews to guarantee that it'll work for your product! Good luck!

http://www.newegg.com/Product/Product.aspx?Item=N82E16820226044

Newegg used to be really good, but about two weeks ago there was a user on here who had purchased ram from them.  The ram did not work, they insisted on charging a 15% "restocking" fee to take it back.  Might be cheaper, but better hope it works or it wille end up costing more.

They charge a restocking fee if you purchase the WRONG item. If it is faulty, they'll ship you a new one for free. I've also had them replace parts for free, and I've had the manufacturer reply to my review when stating it didn't work, and the manufacturer was happy to replace it SOLELY from a bad review.

That was a user's oops.

Better to buy from a decent source in the first place, then…