Help: Late 2009 27" iMac issue; screen video only in safe mode

[mtbdudex]

Well I purchased a new late 2015 5k 27" iMac as my main computer November 2015, so the still working Late 2009 27" iMac was put into my wife's craft room as her computer, form November 2015.

It's on the latest OS X El Capitan (10.11.x) ., had 8GB or RAM, I saw 16GB RAM for $45 via Amazon so installed that 3 weeks ago.

Well, 2 weeks ago it started to act flaky, by that these weird start up screens were showing up.
First a normal start up screen, then 50% in a Double start up like this:

If you waited a long-long time it would finish the start up.
Limped along for 3-4 days like that, then it showed these screens and would not finish the start up

.

Well, I thought maybe system got corrupted,so I did:

1. PRAM reset
2. VRAM reset
3. Ran disk first aid via the Recovery tools start up method

Nadda nothing helped

.

I said "screw it", did a total reformat of the drive.

attempted to do a full restore, it got locked up part way thru the restore, loaded the system but not applications!

Tried a fresh install of OS X there

That also locked up part way thru

I then proceeded to .... yep, I wiped the external FW800 2TB hard drive, as I have a 6TB NAS where I put the last TimeMachine complete backup set to, and attempted to install latest OS X there for a boot disk w/o any system Junk there.
That would NOT finish using the 2009 iMac as the computer, as screen weird things showed up, and I could not finish the initial setup menus.
I finished that by going thru sloowwww USB2 on my new iMac 2015 to make a external boot drive.

Oh, I also found my original DVD's and ran the full hardware tests

I was so hoping to finda reason for this weirdness, nadda it said "all ok" ??

.
Tested the new 16GB memory, then I went and re-installed the original 8GB memory, still saem start up issues and

.

Full test took 43 minutes,nothing found

So - that's where I am, looking at this start up locked screen

In SAFE MODE, via shift key, it does load

 

[danniexi]

I'm going through a similar issue. however, my iMac (late 09 27") will not boot up at all. took it to the genius bar, did a full diagnostic test, found out that it's the video card not working. they said they highly doubt its the logic board.

here's the kicker: the cost of the video card is $599. wtf. i've searched ebay, and two listings came up that were cheaper (around $250) from a shady manufacturer from china claiming that they were refurbished. i have yet to find anything else that is from a remotely reliable source and decently priced. such a shame since this is my main computer and as of now, have to rely on my macbook air to all of my general computing needs. i have already contacted two third-party repair shops that might get the part at a cheaper rate, but awaiting responses from both.

as of now, i'll either repair or pretty much be forced to buy a new one. not sure if i want another iMac as of now. I was hoping it would last me a few more months before a new redesigned rMBP is announced, but my plans might change.

 

[MacVidCards]

These guys are solid:

http://www.dvwarehouse.com/661-5314...4670-256MB-for-iMac-27-Late-2009-p-38152.html

They have a variety for different iMacs.

We are still looking for a local LA partner to develop replacement iMac cards with.

 

[mtbdudex]

Some videos, here's going from single to dual start up bars, happens at 49 seconds

Trying to install OS X again, bad board causes weird issues

Safe Modes starts up but look at the video bands before finished

 

[MacVidCards]

black bands rising from bottom is standard "no drivers" behavior, what it means to use "safe boot", only the EFI drives the card

 

[mtbdudex]

These guys are solid:

http://www.dvwarehouse.com/661-5314...4670-256MB-for-iMac-27-Late-2009-p-38152.html

They have a variety for different iMacs.

We are still looking for a local LA partner to develop replacement iMac cards with.

I've got the 4850 512MB graphics card in it, how much is that card?
[edit] wow $389, not cheap at all .. http://www.dvwarehouse.com/661-5315...12MB-for-iMac-27-Late-2009---NEW-p-38382.html

When I ran hardware tests why does it not come up as bad??