Faulty I game board...my fault?

[Tilt]

Hi,

My I game board had a problem so I sent it to a technician, I was said my board was ok but the eprroms were corrupt. He changed them and I was said the board was ok.

When I got the parcel today, something had come off the board, see picture, at the bottom, in the middle ( the black "square" called "3INXlNX"), I do not know if I put it back the right way.

Could anyone tell me? Could anyone tell me the role of this " square" and could that cause the board not to work properly?

In case, it is not put properly, how can I remove the damn thing?

Thanks a lot.

CYRIL1973

[Tilt]

« Reply #1 on: May 09, 2011, 03:22:06 PM »
Hard to see since the picture is not that big. But generally all of the chips are put in the same direction, so that looks good. Also, one of the corners should have a beveled edge that should match up with a bevel in the socket. This is supposed to keep someone from plugging it in wrong. It's not foolproof though. But I'm sure someone else can verify it for sure.

poppo

« Reply #2 on: May 09, 2011, 04:31:06 PM »

   
It's installed backwards.  In your photo the XILINX words are upside down.  Pull the chip out, rotate it 180 degrees, and re-install it.  The XILINX should appear as you would normally read it.  If you look carefully you'll see there's one of the corners is slightly cut off in a diagonal / (or bevel as poppo stated) that indicates where pin 1 is .  On your socket you'll notice a matching cut off corner.  After you fix that keep your fingers crossed that you didn't damage the chip if you powered it up as shown.

I take you you probably don't have a PLCC chip puller? The next easiest way of pulling it is to get a couple of paper clips, straighten them out, and make a small 90 bend on the ends, it should look like an L when you're done.  Insert one into the upper right corner of the chip socket and the other in the lower left corner of it.  Gently pull up evenly and it should come out ok.  Make sure no pins got bent in the process.  Put it in correctly and see what happens.  Good Luck!

Tilt

« Reply #3 on: May 09, 2011, 04:43:26 PM »

But aren't the others all that way too? Look at the 'Phillips' on the other chips (I flipped the picture over). But the diagonal corner should tell for sure.

poppo

[Tilt]

« Reply #4 on: May 09, 2011, 05:29:50 PM »

   
Yeah, poor engineering.  I'm used to seeing pin 1 always oriented the same direction on a board.  IGT is willy nilly, whichever way they felt like apparently.  Anyhow, here's a photo of one of my boards that shows it with the correct orientation.  Same as the i960 cpu chip. 

Tilt

[Tilt]

« Reply #5 on: May 09, 2011, 05:47:34 PM »

Yep. It's upside down. Now all he can hope for is that it didn't    Most chips don't like to be plugged in backward.

poppo

« Reply #6 on: May 09, 2011, 06:01:37 PM »

Yeah, sometimes you get lucky and it doesn't harm anything, other times it's toast. I've done it a time or two with a Base Chip or GME without damaging anything, but I've never put a FPGA in backwards so we'll have to wait for Cyril to post the results. 

Tilt

« Reply #7 on: May 11, 2011, 03:56:10 PM »

Hi,

Nothing got fried in the end even though the processor was actually upside down. When I put it back properly, the machine worked great.

Thank you all for your posts.

CYRIL1973