Announcement

Collapse
No announcement yet.

EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

    I did it again – I had to fulfill my inner desire to fix yet another old piece of hardware. This one is actually kind of worthwhile, too – it’s an EVGA e-GeForce 7600 GS AGP video card, model P/N: 256-A8-N542-T2. With the popularity of “retro” PCs from the Win9x to XP era going up, and the diminishing supply of decent AGP cards, it is expected their prices will go up. Or is it? I bought the this video card rather on the cheap side (~$9 USD shipped to my door), because the eBay seller listed it for parts or repair (and correctly noted the bad capacitors.)

    So, here is the GPU, as I received it:

    Sacon FZ capacitors at their finest again!

    I was feeling a bit uneasy, because way back I acquired two other EVGA GeForce 7600 GT cards (PCI-E versions) with bad Sacon FZ caps, thinking they would be easy repairs. They were anything but that. In fact, I never succeeded to fix them, because both of them blew their RAM chips when the caps went bad. I tried replacing those too, and got the cards to sort-of work (with artifacts, at least.) However, this experience has made me always be a bit cautious when dealing with EVGA cards and completely busted Sacon FZ caps. In particular, when Sacon FZ caps go bad, their capacity drops like no other. The Sacon FZ on the 7600 GS card above were no exception – they all measured in the 600-1000 pF (picoFarad) range!!!

    Of course, at under $10 and no one else interested in the above 7600 GS, I figured I might as well try to save it from its doomed fate otherwise. Like always, I started by cleaning the card, noting down which caps filter each rail, and then taking high-res pictures, in case something goes up in smoke (after the repair).
    https://www.badcaps.net/forum/attach...1&d=1591483007
    https://www.badcaps.net/forum/attach...1&d=1591483007

    There are 5 major rails on this video card, and I marked the caps for each:
    1) 12V rail for GPU VRM high-side (2x 16V, 470 uF caps with a single blue dot)
    2) 5V rail for RAM VRM high-side (1x 16V, 470 uF cap with two blue dots)
    3) GPU V_core (3x 6.3V, 1500 uF and 1x 6.3V, 1000 uF caps with a single blue stripe)
    4) RAM V_dd (2x 6.3V, 1000 uF caps with two blue stripes)
    5) GPU V_tt (1x 6.3V, 1500 uF cap with three blue stripes)

    I did NOT try powering the video card with the bad caps in this state – not even for a brief test. Instead, I went straight to removing them.



    The above pictures should also reveal how the caps are connected.
    C29 and C34(?) - input 12V rail (GPU VRM high-side)
    C137 - input 5V rail (RAM VRM high-side)
    C76, C50, C77, and C71 - GPU V_core (GPU VRM low-side)
    C100 and C135 - RAM V_dd (RAM VRM low-side)
    C59 - GPU V_tt

    As usual, not knowing if the card would work or not, I didn’t put brand new caps on it. Instead, I recapped it with whatever caps I had on hand (all used pulls & tested, except for the single new Rubycon ZLH cap.)


    1) 12V rail ---> 1x United Chemicon KZG 16, 1500 uF (in place of C29)
    2) 5V rail ---> 1x Rubycon ZLH 6.3V, 820 uF (in place of C137)
    3) GPU V_core ---> 2x Nichicon LF 2.5V, 820 uF polymers (C71 & C77) and 1x Nichicon HZ 6.3V, 2200 uF (C50)
    4) RAM V_dd ---> 2x Nichicon LF 2.5V, 820 uF polymers (C100 & C135)
    5) GPU V_tt --> 1x Nichicon HZ 6.3V, 2200 uF (C59)

    Not going to talk about the ESR of my replacement caps, because obviously they are light-years ahead of the Sacon FZ caps (even when they were new.) Capacitance-wise, I did drop the GPU V_core slightly from 5500 uF total before (3x 1500 + 1x 1000) to 3840 uF total now (a little over 30% drop.) But that shouldn’t be an issue, especially for testing. For OC-ing, it would probably be better to have slightly higher capacitance, since this card’s GPU V_core VRM is single-phase only. I’ll probably end up gutting the Nichicon HZ caps, since they have a 2005 date code (known to be affected by the issue Nichicon had with their HM, HN, and HZ series between 2001-2004 and a few from 2005.) Will likely replace them with 2700 uF Rubycon MFZ… or rather, add a second Ruby MFZs on the GPU V_core and put something more regular in the range of 1500-1800 uF on the GPU V_tt, since it’s a linear rail and doesn’t care about ESR as much. That will be for another revision, though.

    Now the more interesting question at hand – did the video card work?
    Well…

    Yes it did.
    And all of the caps and VRMs run super-cool.

    On the other hand, the GPU chip core is not so cool: 56°C idle with an open case in a warm 28°C (83°F) room temperature. Putting any load on the card for more than 2 seconds easily brought the GPU core to above 60°C, despite the stock fan running full blast all the time (and being very loud, too.) For a GPU chip based on nVidia’s 7000-series, bumpgate damage is guaranteed if the card is used with any significant load. So I did not test it further, aside from a 5-second 3D load test to check for artifacts. The next step would be a heatsink / cooler mod – something I do/show in this thread:
    https://www.badcaps.net/forum/showthread.php?t=70502

    So, this one is… to be continued.
    Attached Files
    Last edited by momaka; 06-06-2020, 04:46 PM.

    #2
    Re: EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

    I had an AGP video card just like that and the 7-series was the last of the eVGA video cards confirmed to still use Sacon FZs. I chucked that one by the mid-2010s, IIRC!

    Because I didn't have the required stuff to expel the Sacon FZ caps and recap it properly!

    And when I decided to chuck it, I didn't recall any caps bulging, but with Sacon, I don't give a fuck!

    That GeForce 7600GS (I got my GeForce 7600GS in 2007, BTW) was on my 2004 Asus A7N8X-X, which was the same one with the KZGs suddenly bulging when sitting on a floor, FFS!

    Also, IIRC, Nvidia terminated AGP support after 182.08. IIRC, Windows refused drivers on AGP after 182.08.
    Last edited by RJARRRPCGP; 06-06-2020, 05:12 PM.
    ASRock B550 PG Velocita

    Ryzen 9 "Vermeer" 5900X

    16 GB AData XPG Spectrix D41

    Sapphire Nitro+ Radeon RX 6750 XT

    eVGA Supernova G3 750W

    Western Digital Black SN850 1TB NVMe SSD

    Alienware AW3423DWF OLED




    "¡Me encanta "Me Encanta o Enlistarlo con Hilary Farr!" -Mí mismo

    "There's nothing more unattractive than a chick smoking a cigarette" -Topcat

    "Today's lesson in pissivity comes in the form of a ziplock baggie full of GPU extension brackets & hardware that for the last ~3 years have been on my bench, always in my way, getting moved around constantly....and yesterday I found myself in need of them....and the bastards are now nowhere to be found! Motherfracker!!" -Topcat

    "did I see a chair fly? I think I did! Time for popcorn!" -ratdude747

    Comment


      #3
      Re: EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

      Excellent work momaka as always, thank you for your write up.

      Comment


        #4
        Re: EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

        Thanks diif, glad you like it.

        More cards to come, for better or for worse.

        Have an XFX GeForce 6800 XT AGP that needs posting too.

        Comment


          #5
          Re: EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

          In my opinion the only thing that makes this card valuable is that it is one of the most powerful AGP cards.

          Excelent work as always momaka. Does it support hardware acceleration on youtube?

          h264 with LAV codec and media player classic?

          Comment


            #6
            Re: EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

            Originally posted by goodpsusearch View Post
            Excelent work as always momaka. Does it support hardware acceleration on youtube?

            h264 with LAV codec and media player classic?
            Thanks!

            I'm not sure if YT still supports HW acceleration on this card. But I'd like to think it does, because up until recently, computers with onboard GeForce 6100/6150/6200 chipsets still saw considerable improvement in YT performance over other IGPS from the same era. Last I checked some time ago (maybe a year or two), YT still officially supported acceleration on GF 6 and 7 series.

            What I can confirm is that on my test PC (single-core Athlon 64 3200+ OC'ed to 2.5 GHz), the CPU usage with the 7600 GS is a lot lower when trying to play back 1080p high-bitrate MKV video. With a crappy video card that doesn't support acceleration (older ATI Radeon or GeForce FX 5x00 / GeForce 4 Ti), 1080p is a choppy slide show at best. With the 7600 GS, it works smoothly for the most part, but occasionally does stutter.

            I haven't tested YT recently on that test PC, mainly due to issues with it (LAN is flaky, as are the USB ports and pretty much anything else connected to the SB.) But last time I did try it (around a year ago), YT ran smooth all the way up to and including 720p @ 30 FPS. I think I was testing a GeForce 7300 GT AGP back then, which also uses a G73 core, but slightly crippled (less pixel and vertex shaders.)
            (Post on the 7300 GT can be found here.)

            Originally posted by goodpsusearch View Post
            In my opinion the only thing that makes this card valuable is that it is one of the most powerful AGP cards.
            Yeah, it's up there on the list, but there are still more powerful cards than it.
            Radeon HD3850 and HD4650 AGP come to mind, of course.

            The GeForce 7800 GT AGP and 7900 GS AGP are also a lot more powerful than the 7600 (actually, they are the most powerful DX9 cards from nVidia.) On the ATI side, the Radeon X1950 Pro is also more powerful than the 7600 GS, as are the HD3650 and HD2600, despite both of these last two being only 4-ROP, 8-TMU cards (they make up for it mostly by the higher core clock and more efficient shader architecture.) The X800 (XL, Pro, XT) is more powerful than the 7600 GS, too. But it is a DX 9.0b card only, so it's not an exact apples-to-apples comparison. If anything, I think the X1650 and X1600 are about the same as the 7600 GS, if not slightly weaker.

            What I like about the GeForce 7600 GS, though, is that it is only rated for 27 Watts TDP.
            https://www.techpowerup.com/gpu-spec...00-gs-agp.c751

            This makes it a really cool and efficient GPU, provided that the right heatsink is installed (on mine above, it clearly isn't... though of course I will change that eventually. )

            Also worth noting is that the GT version (which only exists for PCI-E, BTW - don't get excited about the no-name eBay 7600 GT AGP cards from China ), while clocked higher to 560 MHz (vs. 400 Mhz... or about 40% increase in clock) is rated for 40 Watts TDP (almost 50% higher power output over the GS.)
            https://www.techpowerup.com/gpu-spec...e-7600-gt.c152

            Apart from that, the GS and GT versions use the same exact G73 core, so a GS should technically be convertable to a GT with a core OC. Likewise, a GT can be converted to a GS by lowering the clock. The only that separates the two are the RAM speeds, with the GS almost exclusively using rather slow DDR2. The other thing I'm not sure about is if there are any differences in the core voltages between the GS and GT. But they might not be, as was common with early GPUs.
            Last edited by momaka; 06-16-2020, 05:37 PM.

            Comment


              #7
              Re: EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

              I've got 3 HD4650 AGP gpus, all of them working.

              2 of those are Asus with very good coolers and the other one is a no name one with a pathetic heatsink installed on top of the gpu.

              The PCI-e to AGP converter IC gets quite toasty though

              Comment


                #8
                Re: EVGA e-GeForce 7600 GS AGP 256MD2 [256-A8-N542-T2] with bad caps - fixed

                Originally posted by goodpsusearch View Post
                The PCI-e to AGP converter IC gets quite toasty though
                Indeed it does on those ATI cards. The bridge chips really do need a heatsink. Not sure how big, though. I have a few ATI cards with such chips that I plan on putting a passive heatsink, just to see how that works (well, it will certainly be better than a bare IC core, but it may still not be enough without moving air / airflow.)

                On that topic, nVidia bridge chips are not much better either - at least the GeForce 6 series, that is (like GeForce 6600 AGP and GeForce 6800 AGP.) I was actually working on a 6800 XT earlier this week (modding the cooling solution after recapping it.) With a Northbridge-sized heatsink on the bridge IC and a small 40 mm fan hooked on 7V, this was just enough to keep the bridge IC probably in the area of 50C. With just the heatsink and no fan, I couldn't touch it after a few minutes - it was that hot. So the crappy heatsinks some manufacturers put (both on the GPU and bridge IC) are almost always not good enough.
                Last edited by momaka; 07-02-2020, 07:21 PM.

                Comment

                Working...
                X