Blown 4870 :(

shadyMrPatch · **Blown 4870 :( -** 05-10-2010, 21:27 | posts: 4 | Location: Norwich, UK

Just a quick question...

I have a 4870 512 from Club 3D (i think). I replaced the stock cooler with a reserator, put sinks on the VRAM and put fans in to blow over the whole lot. Its been running this way for a year or so with no problems.

Load temps never beyond 60c.

Anyway after a reboot this morning I got a bios beep code saying that my VGA adaptor had failed.

I have got it booting now however there is a heat sink left on the graphics card that is red hot, its the one at the end of the board where the 6 pin power connectors go.

Its almost untouchable after nothing but 15 minutes of reboots/looking at post screen/looking at BIOS screen.

Can anyone confirm if this is an expected tempoerature as I'm no longer sure that I've actually borked the card... (I'm slightly concerned that its the mobo now :/ )

Cheers,

Rik55 · *Last edited by Rik55; 05-10-2010 at 22:35.*

Sounds like the cards VRM's (Voltage Regulator Modules - MOSFET chips- as seen under the cards aluminium heatsink) and they do get very hot under load. Not sure if it should get that hot on the BIOS screen though.

shadyMrPatch · 05-10-2010, 23:32 | posts: 4 | Location: Norwich, UK

yeah - sounds like thats what I'm talking about. Thanks for the reply.

Thing is nothing has changed internally for ages, not really since I added the extra fans to keep the VRAM chips cooler, and that must have bee 7-8 months ago. Now suddenly.. boom

Anyway - although I'm booting I can't get anywhere with it. It hanging at bios, or if it gets past that it launches into the Win 7 install from disk and freezes at the first graphical 'starting windows' bit.

I've knackered something, now its a case of swapping parts out til I find whats up... ho hum.

shadyMrPatch · 05-15-2010, 17:02 | posts: 4 | Location: Norwich, UK

Final update:

First - thanks for your suggestions, however the card/computer has mysteriously started working again. I pulled all but the essentials out and pointed a large desk fan at the gfx card and it booted first time, went straight into the fresh windows install I had on there and ticked over seemingly unfased by the recent problems.

I ran GPU-Z and Riva tuner. Both were reporting the GPU core temps at about 43C, and the VRM temps at about the same. Stable for 15-20 minutes.

I ran a couple of instances of rthdribl [http://www.daionet.gr.jp/~masa/rthdribl/] which pushed the GPU to 98% give or take, the core temp went to about 58, the VRM 1&4 temps were around 60C, 2&3 at about 62-3C whilst pulling about 50 amps. Which seemed pretty reasonable.

After 20 minutes of this I returned it to idle and turned off the desk fan after the VRM temps had dropped back to the low 40's. VRM temps climbed to 55-58C.

I put it under load again and the VRM temps climed to 95-98C and stuck there, I gave it about 20 minutes again and they didnt go any higher. This seems terrifyingly high to me but google would have me believe that this isn't unusual, certainly with stock coolers.

I've stuck everything back together again and its been idling for 30 minutes now and the VRM temps are low 50's which would suggest that having the sides on and everything in place is assisting the airflow over the VRM sink. I haven't put it under load yet but I think I'm back to a fully functioning computer.

I would imagine that once under load I'll see an upper temp on the VRM of 95C, which is pretty much what I remember from when I first put my WC stuff in, and hasn't been a problem for the last year or so.

Thanks for the replies, I hope that this might be of use to someone else in the future and if I ever work out what the f%&k happened I'll come back and update.