Help identifying resistor on Nvidia GT 650M GPU - Page 1
Forum section: electronics / repair

author: rickmoranis
author_rank: Newbie
timestamp: April 16, 2016, 05:24:51 pm
content: Hi all. I need to identify what sort of tiny surface mount resistor this is and ask for advice on how you would go about soldering one on. I do not have a SMD reflow kit but I am willing to get one if it takes that to fix this. I do have a Hakko FX-951 with several small tips. The image shows which resistor it is. I know very little about GPU hardware itself but I'm guessing this part is crucial to its operation because it no longer works with this resistor missing. I've attached a pic showing the missing resistor outlined in red, it was detached from the GPU and lost afterward.I have tons of laptops with nvidia GPU's that I could take one off of, I'm just clueless as to exactly what the rating of this resistor is and if it is a common component I could remove from donor device.The gpu is an nVidia GT 650m GK107 (N13P-GT), I can tell from this nvidia hardware documentation PDF (https://media.readthedocs.org/pdf/envytools/latest/envytools.pdf) that the following products use the same GPU, but I just don't know nearly enough about component level hardrware to know if this resistor is something common among other GPUs as well.device id product0x0fc0 GK107 [GeForce GT 640]0x0fc1 GK107 [GeForce GT 640]0x0fc2 GK107 [GeForce GT 630]0x0fc6 GK107 [GeForce GTX 650]0x0fd1 GK107 [GeForce GT 650M]0x0fd2 GK107 [GeForce GT 640M]0x0fd3 GK107 [GeForce GT 640M LE]0x0fd4 GK107 [GeForce GTX 660M]0x0fd5 GK107 [GeForce GT 650M]0x0fd8 GK107 [GeForce GT 640M]0x0fd9 GK107 [GeForce GT 645M]0x0fe0 GK107 [GeForce GTX 660M]0x0ff9 GK107 [Quadro K2000D]0x0ffa GK107 [Quadro K600]0x0ffb GK107 [Quadro K2000M]0x0ffc GK107 [Quadro K1000M]0x0ffd GK107 [NVS 510]0x0ffe GK107 [Quadro K2000]0x0fff GK107 [Quadro 410]You may be asking yourself 'why is it so important to you to repair a GPU from 2012? buy a replacement for 10 bucks'... unfortunately for me it is not so easy. The computer is a macbook pro retina a1398 MC976LL/A EMC #2512 Mid-2012 and all of these macbook pro retina editions used a proprietary interface for their SSD, you cannot swap SSD's between the models, so if I were going to just replace the motherboard I'd have to make absolutely certain the MBP was the same EMC# produced in the same months. The motherboards are rare and expensive or I could buy an entire replacement laptop but they still hover in the $1,000+ range.Thanks so much for any help you can offer.

author: wraper
author_rank: Unknown
timestamp: April 16, 2016, 05:32:04 pm
content: This is a capacitor, just remove from another GPU and use instead. Value is not so critical. Although I have a doubt this capacitor was a source of the problem you might have.

author: rickmoranis
author_rank: Newbie
timestamp: April 16, 2016, 05:34:35 pm
content: haha good to know! Is there any way of telling which kind? as far as i could tell there were no letters/numbers/series of colors. Just an off beige.. thing

author: wraper
author_rank: Unknown
timestamp: April 16, 2016, 05:42:42 pm
content: resistors have a black top side and are half of the thickness.

author: Rasz
author_rank: Super Contributor
timestamp: April 17, 2016, 03:43:36 am
content: value doesnt matter all that much, its just a bypass capand as wrapper said its not the source of your problemsno offence, but if you cant tell cap form resistor its better to start by describing the problem

author: Fulcrum
author_rank: Regular Contributor
timestamp: April 18, 2016, 09:45:53 pm
content: Could be that OP has a legitimate reason the replace it, guys.What is the reason for you wanting to replace it? Is it physically damaged, or what?

author: rickmoranis
author_rank: Newbie
timestamp: April 18, 2016, 11:17:49 pm
content: Yes the legitimate reason is the MBP worked perfectly fine before and now it doesn't at all. Now it just beeps 3 times upon attempting to boot, no video display, no post. Most of the documentation will tell you 3 beeps = bad ram module, however, the RAM on this unit is soldered directly to the MB and it never used to beep 3 times upon boot.This isn't my first rodeo with mac hardware. I've replaced numerous mac logic boards from the 90s - now. I've replaced keyboards on MBPs that require taking out 50+ 000 phillips head screws. I've repaired literally hundreds if not thousands of laptops in my ~20 years of experience. I discharge static off me before I begin working, I lay out all pieces on ESD safe pads and keep every removed component in or on a static bag while I work.The only thing that went wrong when I was replacing the battery in this MBP was that when i lifted the heatpipe the capacitor appeared to be stuck to the thin plastic shimmy that prevents the heatsink from making contact with the solder points on the top of the caps. I believe the cap was stuck to the shimmy and it came off with the shimmy/heatpipe. I don't typically do component level repair but this situation warrants it because 1) it is my bosses computer, 2) a replacement motherboard will be hard to find and expensive, 3) a replacement identical model laptop is over $1,000 and my boss isn't going to want to pay that for a 4+ year old laptop.I was really just hoping someone here could shine some of their knowledge into my darkened ignorant mind. Knowing little about components I don't really understand the very basics-- do these things have to be mounted a certain way or does it not matter which end is which? Are they exceptionally fragile to the heat of a soldering iron or can they withstand a good bit of heat without being destroyed? Will too much solder change the resistance thereby rendering the component ineffective? Can other stuff like wire glue be used or is that not appropriate for various reasons? etc etc etc.

author: vze1lryy
author_rank: Regular Contributor
timestamp: April 19, 2016, 03:08:49 am
content: GPU won't cause beeping on these models. You probably pressed on the CPU too hard since they share a heatsink... been there, done that. The real question is why is the CPU heatsink/heatpipe being touched for a battery replacement? Is there a part being left out here?That is a ceramic capacitor without polarization, but again, it isn't the problem. My best guess is if the heatsink was screwed with the CPU was crushed, with its integrated memory controller, which is why you hear beeping.This model board is a POS anyway. Even if the GPU isn't your problem now, it will be in three months. Apple has an extended warranty program set up for it that expires in December, these chips were shit!

author: imidis
author_rank: Frequent Contributor
timestamp: April 19, 2016, 07:09:18 am
content: Don't work on too many macs, but generally, video on laptops issues don't really result in any beeps, maybe artifacts, maybe no video. But you can try replacing it. Curious to see a pic of all the components that were under the heat sink for visual clues.

author: Ice-Tea
author_rank: Super Contributor
timestamp: April 19, 2016, 09:24:22 am
content: Quote from: rickmoranis on April 18, 2016, 11:17:49 pm- Doesn't matter which end goes where.- It will accept a fair deal of heat but in general: keep the heat exposure as short as possible- Too much solder does not matter as long as you don't short two pads together- I have no idea what wire glue is- Chances that this is the reason why your board malfunctiones are limited.

author: senso
author_rank: Frequent Contributor
timestamp: April 19, 2016, 11:07:20 am
content: It wouldn't surprise me that when you unscrewed the heatsink the solder balls of the gpu broke/popped, already happened to me, old laptop, start dismantling to clean and there goes the gpu, the solder balls where already stressed and when you remove the heatsink that pressure is no longer there, and pop.GPU failures can be fun, can go from small artefacts after long periods of heavy load, can be random artefacts under no load, random driver crashes and no artefacts, swapped colours, bands, lines, to being difficult to boot, booting without image, or just plain dead, swap the dead gpu and they come back again to life.This is a bit exacerbated in the Macs, because airflow is mostly existent and they run hot hot hot.

author: rickmoranis
author_rank: Newbie
timestamp: April 19, 2016, 06:59:25 pm
content: Thank you all for your input.In reference to the last few comments-I took the heatpipe off because my boss informed me that the machine ran ultra hot and the fans were spinning at full speed all the time. Having seen this problem with 100s of laptops it was obvious that the heatsinks had some lint/dust/hair etc clogging them which prevented the fans from effectively cooling the heatpipe. Having worked on 1000s of laptops I knew that it almost certainly also had some garbage silicon thermal paste that was likely dried out and cracked off sandwiching the CPU/GPU and probably acting more as an insulator at this point than a conductor of heat. Also, having seen posts about peoples disappointment with apple heatsink finishes (they are not even close to mirror finish, not even remotely polished surfaces, tonnnns of pits/grooves in the metal) I decided I wanted to look at the points of contact to see if I needed to polish them down.So, I took the heatpipe system for all of those reasons. I did so extremely carefully, working at a slow pace as to not cause any microfractures between the solder joints because of the previous information given by my boss (that it got hot as hell and the fans ran at 100% all the time). Having known that the machine had been running hot in the past it made me all the more cautious about putting even the slightest amount of pressure on the heatpipe or any of the PCBs inside.If it does end up being microfractures in the solder joints I do not have access to a BGA reballer but I can get access to an SMD reflow station. Have people had any luck putting these boards into ovens like they do with full sized pci-e graphics cards?

author: imidis
author_rank: Frequent Contributor
timestamp: April 19, 2016, 09:06:56 pm
content: Why fixate on a problem that may or may not exist?It is telling you the beep code for RAM. So, it is most likely a ram issue. Bad ram or bad ram connections can cause the beep code and no video display. If it did get hot enough to kill the components it would like be an uneconomical repair.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: April 19, 2016, 11:07:45 pm
content: Oven works. Just ask Louis Rossmann. He's posted in this thread already.If you do take a heat gun and heat the GPU for a short amount of time and it works you will know that that is most likely the fault.