The component side is b and numbering starts on the left. The burnt pin is B7, which is a clock pin. AFAIK, that should not carry much current, so no idea why it burned.

I strongly suggest you avoid testing potentially damaged and/or damaging hardware on anything other than a sacrificial board . This cheap as chips video card is not worth risking a motherboard, IMHO .

Hopefully somebody more knowledgeable than I am will chime in with some options .
If that does not happen, I suggest you chuck the card to recycling before it claims a victim ( if it hasn't already, that spark did not sound reassuring).

I call these hardware trap. It causes a short in other components so the owner sells it as "untested".
Another unfortunate soul buys it, burns out his mainboard with it, then he sells it too to recover some of his losses.
The card starts it's long journey on auction sites and causes a lot of damage. It appears then disappears again only to reappear a few months later.
Just do the right thing, smash it to pieces.

I do not know what happened with the previous owners, how the pin burned...
Your advice is wise, that's why I'm not gonna try it anymore since I actually do not have a a sacrificial board or someone have an advise how to fix it.
Spark aside the mb seems work fine, luckily...
Unlucky the card is not that cheap, it is a savage xtreme 32mb, quite rare... :\

I know it's difficult, I had a CPU-killer mainboard before. It looked perfectly fine but fried the CPU instantly. I couldn't find anything wrong with it so I foolishly tried another CPU with the same results. Desoldered the external connectors and trashed the rest.

Well for sure i'm not going to sold it, but your story about the motherboard made me think there could be a short on the card, I will check with multimeter, while waiting for advices, eventually I will throw it...

This is strange. The burnt part is the one that doesn't carry any current when the card is properly inserted (pins in the AGP socket are staggered, and only contact the golden fingers in the area where they are wider). You don't need to repair anything, just gently scrape away the burnt parts in the eventuality that they become conductive.

How the initial damage might have happened is beyond me. Maybe improper insertion, or being mis-aligned in an universal AGP Pro slot, since the card doesn't seem to have the "wing"/registration key at the end of the connector.

I would certainly not toss the card, but wouldn't test it on a valuable motherboard either. Also carefully inspect the contacts inside the AGP slot on the board that sparked, as any damage could turn it into a "hardware trap" and the cycle will go on.

Good catch, the spark came out from a mb with universal agp slot, while the first time I have probably tried it in a agp 2x slot! Also thanks for clarifying that the golden fingers are the area that make contact with the slot.
I also tried the continuity tester and apparently there is no short, also the burnt part isn't conductive.
What can I use to scrape away the burnt part?

About the mb with the spark I tried the system with another sacrificable video card and it worked fine, should I try to inspect the agp slot with a magnifier?

I was referring to the initial damage (from the previous owner), maybe it was mis-aligned in an AGP-Pro slot. The standard (non-Pro) slot doesn't really allow this to happen.

The burnt stuff can be removed by carefully scraping with the tip of a very sharp blade.

Slot should be inspected, check for burn marks and if all the contacts retained their "springiness". Magnifying glass and good lighting help a lot.

Got it.
I inspected the agp slot, it seems in good shape, no tracks of burns, is it right?

Edit: I tried the card in a 440bx system and it boots fine... so what? I'm perplexed...

Are you sure it's a burnt spot and not some sort of physical damage? I've had cards look like that when the seller shoves multiple cards in a box with little to no packing materials

I don't know how flaky the pin material is (difficult to really see well from the pic), but you wouldn't want the contact material to let go of the contact to short some other part of your rig.
I'd agree with the mention to remove the pin material as to at least have it not cause any more future potential disasters this way.

I wouldn't throw out the card but I would definitely (clearly) label it!