Toshiba satellite p755-s5390 windows 7

I'm have trouble starting my computer up after doing a ram upgrade. I when from the original two 2gb ram cards to one 8gb card. Iv tried it in both slots and didn't find any issue with me using one card from what iv looked into. I get a black screen after logo goes away on power up. I have had this isue for two days and could use some help. Iv pitches another 6gb ram card and hard drive just in case should have both next week. If anyone can help I would appreciate it.

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Also my mother bored supports up to 8.5gb so there should be a problem with using 8 or at least I don't think

Put back the original memory.
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I think that the main problem is that you have 8 G in one module.
If you use only one you lose the double channel feature. Some computers has a module limit size.
You should have bought 4+4 G (two modules).
Please give us the new memory specs.
satellite_P755-S5390.pdf

You're having this issue due to your motherboard can only read 4 gb per memory slot. You will need 2x4gb for your pc to read a total of 8gb. Several entries below your post, someone linked memory from crucial, that would be the correct ram that you need. Hope this helps if you have not gotten already sorted out.

Skunk6300 said:

You're having this issue due to your motherboard can only read 4 gb per memory slot. You will need 2x4gb for your pc to read a total of 8gb. Several entries below your post, someone linked memory from crucial, that would be the correct ram that you need. Hope this helps if you have not gotten already sorted out.

I'd hope that "19smokeyjoe94" has resolved this, after a year.