black screen caps and scroll blink 3 time

[pat000007]

I have 2 hp elitebook lapto. One of them make black screen on startup and caps and scroll key blink 3 times.

It is suppose to be memory module error

I take my memory stick from one laptop to the other and the memory stick work fine.

What could be the issue?

Thank!

[WAWood]

@pat000007 

The memory errors include not only the stick but also the motherboard slot.  So, if you've replaced the stick with a good one that you know works, then the motherboard is at fault -- and replacing those is both very difficult and very expensive.