Riva TNT2 16MB - attempt to repair

[trodas]

Once upon a time, there was a graphic card. Not fast one and on the top of that, it used all bad caps. So regardless how hard she try, she was destined to fail from the very beginning. CapXon caps made that promise:

http://i4.photobucket.com/albums/y134/trodas/RivaTNT264MB1-1.jpg

Luckily for the poor card, the user that bought her used her only very sporadically and he also connected her on quality PSU:

http://i4.photobucket.com/albums/y134/trodas/RivaTNT264MB2-1.jpg

So time went by slowly. Till something went wrong and the picture on screen get corrupted:

http://i4.photobucket.com/albums/y134/trodas/RivaTNT264MB3.jpg

Regardless that the card still show BIOS/DOS screens with text nicely, user demanded windws and installed a new GFX card. After that, his PSU ( FSP 250-60GTA ) told him "by by" and died on him. Probably sort of card-revenge that she got replaced by a ATI 9250 128MB card. PSU failure:
http://s4.photobucket.com/albums/y134/trod...SP250-60GTA.jpg (http://s4.photobucket.com/albums/y134/trodas/?action=view&current=FSP250-60GTA.jpg)

But again luckily form the poor cardie - I pitty her, so I decided to save her and fix her. Instead of only 22uF 25V caps I used quite much better ones:

http://i4.photobucket.com/albums/y134/trodas/RivaTNT216MB4.jpg

Of course I measured firs and the whole cardie is powered from 3.3V rail.

http://i4.photobucket.com/albums/y134/trodas/RivaTNT216MB5.jpg

Rams are powered directly from the PSU 3.3V line, so if you want O/C them better, just increase the 3.3V line to say 3.5V... :D

http://i4.photobucket.com/albums/y134/trodas/RivaTNT216MB6.jpg

GPU main regulator produce 2.6V output for core and the two closest caps to the GPU support that voltage. All other show 3.3V on them. I still think that regulating from 3.3V to 2.6V is crazy as the difference is only 0.7V and that it not enought for good regulation and they should power the GPU from 5V rail, getting 2.4V to regulation = much better. But, well - too late.

http://i4.photobucket.com/albums/y134/trodas/RivaTNT216MB7.jpg

However no matter how hard I try, the board is still showing the very same picture, so recap was sucesfull, yet it did not fix the bug. I suspected from the beginning that the resistor pole used to make the 75 ohms VGA output is to blame, so I going to remove it and instead of removed CE filter caps install separate and better 75 ohm resistors and we see... ;)

[Solaris17]

u have mad soldering skillz.

[trodas]

Oh, thanks. But it is not all that hard :) This recap was, in fact, kinda easy. Harder will be the removal of the IMHO guilty resistor pole RP1, witch provide the necessary 75 ohms resistance to ground for the RGB signals from the card.

[Solaris17]

lol still never tried a recap you should run me through it sometime...right now im modding the NB of my mobo again so ppl here know how to make it sli that requires a little soldering but its pretty easy :)

[FreedomEclipse]

I had the same card.... an Nvidia TNT2 32Mb... not quite sure if it was a pro model or not. i was too young & inexperienced & busy trying to find a way how to recover my home work when windows98 crashed