MacPro 5.1 Ram led lit need help

Hi all!!! Ok I have a ram problem on my MacPro. I was notified by Clean my Mac that said that I needed to close some apps because I was low on ram. At first I couldn't understand why I was low on ram I have 13gig and I open about 1-4 apps at a time but not every day so I couldn't understand why I was low on ram so I checked sys info on my ram and OMG I only had 4 gigs left out of 13gigs!!! Slot 1,3,4 sa marked as EMPTY!!! OMG now what?? So I did a few test and I have a few Mac pro groops on FB but not much help there so I hope to get some here. I will copy/paste my tests that I reported on FB. BTW I cleaned all ram sticks connection with alcohol and sprayed the slots with air. Let's just say that the tray needed a good blast of air!! Ok here's my test:

1: Ok did my first test and I've put the good ram in slot 1 (it was in slot

2) and no led BUT got white power flashing non stop no codes. I still

have my org 1 gig ram (2) that I know that they are good and see what it

does.

2: Ok just put one of the "supposedly" dead ram stick in slot 2 and working.

So for now not a bad ram. But now why didn't my first attemp the led

didn't light up on the good ram but it didn't boot got white power

button flash non stop and I put the kida bad one in slot 2 but booting

and it was in slot 1 but got a led lit up??? How confusing this is!!

3: I will attempt to put my 2 org 1 gig mem stick in lot 1 and 3 and see what

it does. Ok just put my 2 org 1gig ram in slot 1 and 3 no leds and I got 6 gigs

now!!!! Now this IS confusing here. Right now my mind is full of ????

YES happy to see that 1 of my supposedly bad ram is ok and working but

yesterday it wasn't working and had a led on slot 1 (3 + 4 for the other

rams). Is there a reason why that my good 4 gig ram didn't get my mac to

startup and got non stop power button flashing or is it because when

using just 1 ram stick must be put on slot 2? For now confusing.

4: Ok put all the ram back and getting the leds lit 1/3/4. So could it be

just a bad ram?? I will remove my 1 gig in slot 4 and replace it with a

good 1 gig that I just tried.

5: Ok no work same led lit on all 3 slots. Hmmm I might have a bad ram I

think that is causing this but I get a chime at startup. So now I'm just

???? as what to do next. So for now I will put back my 2 1gig sticks so

I can get a bit more mem than the 4 gig (6 is better than nothing and

see what I can do next.

6: Ok did a small test to see what it would do, I just removed the 1 gig ram

in slot 4 to see what it would do, now I only have 1 lit led on slot 1

but now getting 8 gigs of ram. So now what???

7: Ok last test for today I just moved my 4 gig stick from slot 3 to slot 1

and no leds on and I get 8 gig for now. So now I have slot 1 and 2 with

dimms and 3 4 nothing and no leds lit.

So now what to do?????? I do have the repair manual for my mac (see pic ) but not much help there maybe I'm not reading it right. So ANY help to try to find this problem WILL BE WELCOMED!!!

Serge

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