Toasted a 7950 - Page 1
Forum section: electronics / repair

author: dovah-chan
author_rank: Newbie
timestamp: November 30, 2014, 03:10:32 am
content: Okay so a few days ago, a friend of mine tried to install an Arctic Accelero Mono Plus aftermarket GPU cooler for his 7950 that I got him as an early christmas present (also if anyone else here is knows a thing or two about GPUs its that reference coolers are LOUD).Anyways, when he handed the card back to me the following day after his attempts to install it I got this:http://imgur.com/a/B4MqXSo I gave him my 7970 and now I'm sitting here with a dead card trying to figure out what can be done for it. It's only a minor inconvenience as I was planning to upgrade to a 390X once it comes out but I thought it would be a fun project to try and repair this thing. The card will power on and work somewhat so its not completely dead and I don't think any other onboard components were damaged other than that small area near the power phases. (it just gives a solid green screen on start up and then after booting past the motherboard logo and windows logo it then the display shuts off:http://imgur.com/a/1ObvR)I also noticed upon closer inspection that one of the main power inductors (labled R22) is black on the inside of it versus all the others which are just the regular silver. I'm assuming thats where it went 'poof' at. Is there any hope for this card or should we just scrap it (or hang it on a wall or something)Oh and the exact card model is the HIS H795F3G2M

author: Shock
author_rank: Super Contributor
timestamp: November 30, 2014, 02:09:43 pm
content: If you can remove that mosfet and clean the surrounding area keeping the pads intact it should be repairable. The carbon will need to be cleaned from all surrounding components. You can measure those neighboring components and compare them against the others that don't have carbon all over them. Any torn pads or burns into the PCB and your chances of success go way down. You want to use ESD precautions handling the card and I think a hot air station is probably required if you need to replace the choke.Less thermal paste next time.

author: Rasz
author_rank: Super Contributor
timestamp: November 30, 2014, 02:31:37 pm
content: well, obviously the problem was not enough electricity conducting thermal paste around the chip ....search here for a video of a fixhttps://www.youtube.com/user/1servicecore/videos?sort=dd&view=0&shelf_id=1there was one with exactly same problemwarning - it might will involve dremeling out pcb because you have quite a burn there and lot of charred pcb, all in all Im guessing it is beyond your capabilities, easiest solution is to sell that card on ebay with clear description - someone able of fixing it will grab the dealyour monkey friend either-used conductive thermal paste and it shorted components on the chip-ran the card with no cooling to 'just test something'-shorted it while it was running by .. I dont know what he was doing, measuring something? screwing around with screwdriver while it was powered on?

author: dovah-chan
author_rank: Newbie
timestamp: November 30, 2014, 04:34:04 pm
content: He used a tube of IC Diamond I gave him, which I don't believe is conductive but the G1 thermal adhesive that came with the cooler for attaching the RAM heatsinks was conductive if I remember correctly. Not to mention that the cooler itself is not compatible with the card. On Arctic's website it says that any 7950 manufactured before February 2013 is not compatible.It appears on the package it was manufactured on the 16th week of 2012. I mounted the cooler myself just to check and it wasn't making proper contact with the cold plate. It's nothing that a shim or something couldn't fix since the die doesn't have an IHS. Anyways I'll see what equipment my dad has in storage and if he hasn't gotten rid of his soldering equipment we might give it a go. Although I think it might be a headache-free option to just sell it off and get him an R9 280 which are dirt cheap at the moment.Also found the video which has the problem and the fix:

author: Shock
author_rank: Super Contributor
timestamp: November 30, 2014, 06:05:29 pm
content: Shame that guy doesn't do English subs or translation. He was pretty brutal with that hand drill. Wonder if He was grinding till He saw a short open or was just going for it. I couldn't tell if He lowered the voltage and under-clocked it as a result or this is the first one He had done.

author: bithead9
author_rank: Contributor
timestamp: November 30, 2014, 06:51:32 pm
content: WOW that thing is charred good.The 2 SMD caps next to it ? One is melted down and the other is missing. Did you remove the other cap? Looks like they are all paired on that board. If you are going to TOSS it out then get an Xacto knife and cut the fried chip off the board. If you go carefully enough you will not cut the PCB. Once it is off you can use a regular solder iron to remove the remnants.In fact you can just cut sideways and break the chip apart (who cares you are replacing anyway). then you will not damage the board. Score it over and over until the chip breaks away. You still need to do it slowly so as not to pull the traces off from the pins on the board.

author: Rasz
author_rank: Super Contributor
timestamp: November 30, 2014, 08:02:19 pm
content: ? c???!.?? ????!yep this is the oneQuote from: Shock on November 30, 2014, 06:05:29 pmI think he says he simply cleaned until there was no more charred material in the hole, then compared resistance. From what I remember he was very gentle with that dremel. underclocking was to check if its stable without one power phase.I was "lucky" to grow up in the eastern bloc = mandatory russian in school (at least they let us learn our mother language after the ww2, unlike first time around in 1780 when they simply forced russian as only permissible language country wide :/)Quote from: bithead9 on November 30, 2014, 06:51:32 pmdude NO, never use force, all you accomplish is stress, fatigue and micro cracks all aroundGFX pcbs are BRUTAL, >12 layers of copper, its very hard to solder on them without preheater

author: dovah-chan
author_rank: Newbie
timestamp: December 01, 2014, 03:26:44 am
content: I might try to repair it this weekend if all goes well in my scheduling. Going to need to a whole afternoon for this thing. I haven't removed any caps or chips at all yet because I haven't had the time.Higher quality picture for the astute eyeAww screw it I can't be darned to clear time for this thing (not to mention we don't have the right equipment anymore since my dad sold his welding and soldering gear off when he moved last month apparently). I also have very fidgety and shaky hands so I'd probably screw it up anyway.Here is the eBay posting if anyone here is interested. [url=http://m.ebay.com/itm/171563857645?nav=SEARCHOh and just for the people here, if one of you guys buys it I'll throw in the accelero mono plus for free.

author: TiN
author_rank: Super Contributor
timestamp: December 04, 2014, 01:49:40 am
content: Easiest from time perspective would be using external VRM for it. Lot of people using it for overclocking for extra power.One of market available units isEVGA EPower, if a 100$USD sounds ok

author: amyk
author_rank: Super Contributor
timestamp: December 04, 2014, 09:29:11 am
content: Quote from: TiN on December 04, 2014, 01:49:40 amQuoteIt's more like an arc welder.

author: Spyke
author_rank: Contributor
timestamp: December 06, 2014, 04:50:01 am
content: The Arctic Accelero Mono Plus comes with little tiny stick-on aluminium heatsinks for the VRM's. Its more likely he shorted one of the mosfets out rather than the heatsink on the GPU with the excessive thermal paste causing it.

author: Shock
author_rank: Super Contributor
timestamp: December 06, 2014, 12:42:38 pm
content: A little extra thermal paste here, a little slip of the screwdriver there, a little hot plug and plug from time to time, with a dash of rubbing vigorously on your pants before working on a board. It all adds up to the same thing really.