5970 toasted,please help

[mystiv]

Hello,
I got a used 5970 a couple of days ago.
At the time i couldnt tell the difference so when i got home i pluged an 8 pin EPS plug instead of an 8 pin pci express plug to the card.
The card started with max fan and both leds red but no signal.
I tried a couple of times then quit.
today i bought a 850W psu with an 8pin pci express plug.

Every time i try to boot i get a black screen with a red error message "power plugs not connected" with both plugs connected.
Im sure the reverse polarities toasted something.Can i find and fix this?
thanks in advance!

[mariushm]

Re: 5970 toasted,please help

Post large clear pictures of the both sides of the board near that connector.

In the best case scenario, some protection diodes may be toasted and you can replace those.

[mystiv]

Re: 5970 toasted,please help

Here are the best photos my phone can do.If they are not good enough i can take some macro shots with my brother's camera.

[ratdude747]

Re: 5970 toasted,please help

fixed your post, please use the "manage attachments" tool and inline insert the attached image... posting low res copies of offsite pics = not good.

[mystiv]

Re: 5970 toasted,please help

Thank you,will do.

[mystiv]

Re: 5970 toasted,please help

I tested what looks like a diode with a multimeter and the cirquit breaks there.



Is it a good idea to brige this with a pencil and see if the card works?

[Mad_Professor]

Re: 5970 toasted,please help

test it on the diode setting to confirm.

R stands for resistor and the infinity symbol means highest level of resistance.

But I can't determine if that's an actual marking on the pcb or something you added to the photo since it does not show up on the other photos.

I don't know what function those smds serve since there is no markings to indicate but there is a matching set up above on the second connector.

Keep looking I don't think this is it.

Look for fuses or bad transistors, I don't see any diodes on the board or any marking for a diode.

[Agent24]

Re: 5970 toasted,please help

Going by the colour that looks like a small ceramic capacitor, which will naturally test infinite on a resistance test.

[ratdude747]

Re: 5970 toasted,please help

Going by the colour that looks like a small ceramic capacitor, which will naturally test infinite on a resistance test.

agreed, that's a SMD ceramic cap.

[mystiv]

Re: 5970 toasted,please help

I added the arrow and r=infinite to highlight the part.Looks like its not the problem after all.Bridged it with a pencil and got the same "power plugs not connected" error.

[mystiv]

Re: 5970 toasted,please help

I measured the componets connected to pin no 8 with a multimeter.
One of the four identical (mosfet?) thingies appears shorted while the other three have infinite resistance between their 3 pins.



All four are marked 1AM T. I have an old ati card with a similar thingy marked 1AM 5.Should i solder it and see if the card works?

[Agent24]

Re: 5970 toasted,please help

If this is correct: http://clivetec.0catch.com/SMD_Codes1.htm then the 1AM means an NPN transistor, model 2N3904 (In fact, Motorola MMBT3904L) You could likely purchase these new very cheaply.

I would be wary of removing one from another card unless you know you can do it easily, it would be quite easy to overheat it.

[mystiv]

Re: 5970 toasted,please help

Its correct, the T mark on the side means built in malaysia!