Nice video, thank you very much. May be as an idea, I saw some similar videos from Russian guys and they all told, that if on of the MOSFETs blew up, it is usually not sufficient just to replace it. In the best case it will work for another week or so and, in the worst, like in yours, it will blow up immediately again. They say, that if you have to replace a MOSFET, you always also have to replace the controller, because it usually is the reason, why the MOSFETs blew up in the first place anyway.
I think you're right. This video ended up being super popular, so I might take another swing at this, just to see if we can finish the job. It'll be a while though!
@@Adamant_IT Yes, i also believe the controller has turned on both mosfets (high and low ) at the same time, creating a path to ground through the low side mosfet probably, blowing the high side one. Replacing the controller too, might solve the issue
@@yosuhara No - its the mosfet driver chip Adam mentions: NCP 81062 from ON electronics. They are available from Aliexpress.com Links to the ON datasheets site: www.onsemi.com/ www.onsemi.com/pub/Collateral/NCP81062-D.PDF www.onsemi.com/pub/Collateral/NCP81174-D.PDF Apparently the mosfet driver chip fails by turning on the lo-side mosfet simultaneously with the hiside mosfet, thus taking out the weaker of the 2.
YOU ARE REALLY AMAZING. MY REGRET IS WHY I DIDNT FIND YOUR CHANNEL EARLIER! A GOOD CRAFTSMAN ALWAYS SHOW HIS MISTAKES SO WE ALL DONT MAKE THEM! YOU ARE EXCELLENT EXAMPLE! REALLY LIKE YOUR TROUBLESHOOTING CYCLES!
That was really entertaining. Shame it didn't turn out as you hoped but hey, after all the replacement surgeries and explosions you still got it to work. That's a big win in my books. Keep it up! :D
thank god for these videos. I have a evga 960 that had a similar meltdown, Inductors exploded and it shorted, and the fan bearing blew out. the blue pcb burnt to a brown color. hoping it didnt destroy the traces in the pcb, that will make this repair a thousand times harder... But i wanted to try and practise repairing components. And this video was exactly what i needed! thanks a bunch!
Lol i did the same thing you did too! I plugged the 960 into a lower wattage psu, a 550 and it took power and fan kicked on, just didnt produce an image.. so i tossed it into my system to be faster with troubleshooting and plugged it into a 850w and suddenly i smell a burning smell, the fan is twitching and came to the conclusion my 850w surged into the card and fried a bunch of stuff.
I always watching your videos, and thank you that u mentioning the degree Celsius of hot air. Make more videos where here and waiting and starting learning
I watch your videos like i watched The Shawshank Redemption or other great movies :))Imagine in high school i was the electronic class and none of those teacher talked like that and was so boring.Now...i watch with big curiosity, you explanation are so good and i understand no matter if my english is bad. :)) GOOD JOB!
Thank You. And yes, learned alot (and I was sure I knew everything🙄). I enjoyed the magnum length video version. I ordered a pizza and told my GF to get lost. OK, I didn't do that.. I just let the air out of her 🤤 Anyhoot, you fought the good fight. Think I will pickup one of these classics. It will feel like an old trusted friend. Cheers 🇺🇸😁🇬🇧
Interesting look into buck regulators. The only thing you didn't try was swapping out the driver i.c. I think that was faulty (thermally unstable) and provided the path to ground for the high side f.e.t. The driver i.c. probably switched the f.e.t. on for too long, killing it.
id love to see you fix some rx 570s an 580s i have a bunch i could send u man, i need fixed, but to see u do it would help me fix mine i love how u go over everything an explain it, SO AWESOME MAN i love you!!
I like your videos very much. Your speach is 98% understandable for a non native, non supreme speaker :) You can teach me electronics - in English! - That is way more rare than you may think...
I love the cheap compact testers/o-scopes. However in this case I'd love to see a decent analog scope, at least in an educational video. Just constructive criticism. Nicely done though.
True that, he's getting confused a lot just because the scope is limited and doesn't show properly what's going on. I think he should see full 12V on the mosfet output, mosfet is either off - 0V or on - 12V, it should not show anything in between.
@@Arek_R. That's not actually true, with such high switching frequency you can't constantly hold 12V or 0V at the output, I will always be something between. And for such purposes there will be no difference between cheap and professional o-scope, only slighly change in readings accuracy. Personally I use ad1102ca from Atten which isn't either cheap or expensive, but didn't notice difference when compared to cheap ones or some high end for thousands of $ ;)
In my experience (not specifically related to graphics cards), if your MOSFETs short, you should assume the drivers have been damaged and replace them as well.
Great demonstration of how buck regulators work in real life. 👍👍👍 After theoretical explanation in a couple of previous videos it's nice to actually see it "in action". 😊😉 Thx for the effort.
Still, a great vid. I had no luck trying to replace a broken off 3.0 USB header pin on an older ASUS mobo, by desoldering/soldering (plan was to us a leg from a LED) but still felt satisfied with my effort in trying.
"the short magically disappeard" :D There's no magic, the problem lays in the method you use to solder the mosfets (or actually any QFN-type components with thermal pads), placing to much solder on pads and then trying to push it out is a bad idea, 'cause you push it in all 4 directions, 3 visible and also the one that goes to G and S pads of the mosfets which you can't see but for sure will make a short circuit ;) So in my opinion it's better to clean the pads from old solder and use solder paste (even some cheap chineese one), SnPb is preffered (by me) 'cause of lower melting temperature :) @1:09:40 you start thinking why it shorted again and burn upper mosfet while it has no connection to GND, it's all caused by failed PWM controller and/or driver which drives low side mosfets constantly so at output you have GND all the time and when swiching upper one it simply burns out ( double lower side mosfets can handle that short, single upper one will blow up)
Forget your Kyles, Jayzs and Linusus.... This real IT problem solving! I wouldnt attempt it myself though... My clumsy fat fingers wouldnt be able to be this precise
I'm a retired electronic tech from the USAF and I've seen a capacitor test good but then go short. Replacing the capacitor corrected the issue of a system blowing a fuse. I'd say replace the Q1 cap even if it tests good.
I find it funny that right after I left the video and commented you need to read schematics, you start looking at schematics. Albeit not the card manufacturer schematics. I wonder why? Also critical because the phase ground didn't end there, couldn't you have traced it farther? I do understand though you showed how you can figure out without schematics what goes where, which is handy if it is obscure or old, but that card wasn't either. Can't you get small business loans to cover ultrasonic cleaners and Schematics websites? I can't find them for free but idk. Thanks, this was awesome! I learned a ton. Entertaining as well.
Please use Flux and see the magic how your soldering will be ! For soldering and desoldering use Flux please ! Very good informative videos I am so thankful to you for your effort and work! Best regards,
Sir, it's 3:48am in the morning... WTHECK just happened.. all I heard was turbo dead.. Mosfett just dropped dead!! 😂R.I.Pieces Mr. Mosfet. Sorry sir, I was quite happy for your accomplishment. Use the donor card.. what else can work as an inductor replacement? Dr. Frankenstein we need an Abby Normal Brain.. A better Mosfet that can handle a fuller load. This way the resistors can still take care of some of the flow.
It's hard to imagine it's worth your time to attempt to repair a 960 board. I don't know about the U.K. but a board like this is worth about $150 functioning, it seems like too much time and effort for not enough potential reward. Anyway, I really enjoy your videos, keep them coming!
at the start of page 13 of the datasheet at 21:57 sec, it's clearly written "if a phase is unused, the differential inputs to that phase's current sense amplifier must be shorted together and connected to the output"
If you have time a nice video would be one where you show how to test each item and what it should look like if it is good. I have several bad video card that I purchased trying to learn. I took a power supply and put 5 volts and 1 amp into the back video card 6 pin plug and tried to follow where the voltage stopped. I jumped the mosfet gates with 5 volts to try to get the mosfet to turn on, and in spots it did. Ground on one side of caps but got no futher. A video starting at the 6 pin and checking each item saying what you should see and what you did see moving along would be great. You know what things should read and jump right along, but a video for more or less beginners step by step would help alot of people I am sure. Thanks for your time and videos.
cleaning with isopropyl alcohol will help a lot and I believe that part that you did not know what it did is some kind of a boos or buck converter for voltage depending on the configuration.
These two pcb's are absolutely identical, I bet down to even a single wire and its physical pos. on the pcb, so it is highly unlikely that that you couldn't take any individual part and exchange it between the two pcb's - with only one exception - if the two boards has significantly different timing specs. Just about all semiconductor manufactorers have don those designs since the mid 60's and Intel, AMD, Realtek and yes Nvidia and ATI too - you get a complete design with schematic diagrams, BOM and most often even Gerber and drill file. I once had a collection of 8 different MB's that original was a Intel BX-440 - only difference was the color of the solder mask, occasional different color of a connectors plastic (never the position) and the top silk screen that stated the name of the OEM - as I remember ASUS, MSI and First apart from Intel, I can't remember the last four :-) They were carbon copies of each other - except from major build quality variations ;-)
Hi I am loving your videos on repairs keep them coming. How ever it is not really a VRM, that term was used when the voltage regulator was on a small pluggable module, hence Voltage Regulator Module. I am guessing the the topside FET is not switching properly maybe the bootstrap capacitor or driver IC is not working properly. The input inductors are only for EMI reduction, if they were not fitted and it went short all that would happen is the PSU would go into chirp mode assuming you do not have any other components in the board that would fail 1st. I believe the weird chirping you saw on the scope was a sign it was not switching correctly, and the waveform on the output of the FET will be a pulsed one from GND the 12V, I am assuming your pocket scope cannot display the correct waveform.
Question is.. have you tested the coils which the mosfets are working together with? If they all have the same characteristics to different frequencies, or if other components have measured values slightly off specs. It's a longshot, but it might be the cause of why it's the first mosfet that shorts, if the harmonics might be off tune causing standing waves, or if some other component interferes. I was thinking, maybe you could trick it into running 2 phases instead of one at lower and moderate load to smoothen the transition to 3 (or 4) phases? I really enjoy your videos and your waffling :)
you may not get many viewers that will stay and watch the whole video, but those that do stay greatly appreciate your hard work!!
81 comments but no comments let me fix that
"we did actually burn test this one" You sure did! 🤣
darn it to late to make the joke xD
should have found it earlier xD
Quite literally
Nice video, thank you very much. May be as an idea, I saw some similar videos from Russian guys and they all told, that if on of the MOSFETs blew up, it is usually not sufficient just to replace it. In the best case it will work for another week or so and, in the worst, like in yours, it will blow up immediately again. They say, that if you have to replace a MOSFET, you always also have to replace the controller, because it usually is the reason, why the MOSFETs blew up in the first place anyway.
I think you're right. This video ended up being super popular, so I might take another swing at this, just to see if we can finish the job. It'll be a while though!
Good advice.
@@Adamant_IT Yes, i also believe the controller has turned on both mosfets (high and low ) at the same time, creating a path to ground through the low side mosfet probably, blowing the high side one. Replacing the controller too, might solve the issue
@@gaspardeelias2485 You mean NCP81174?
@@yosuhara No - its the mosfet driver chip Adam mentions: NCP 81062 from ON electronics. They are available from Aliexpress.com
Links to the ON datasheets site: www.onsemi.com/
www.onsemi.com/pub/Collateral/NCP81062-D.PDF
www.onsemi.com/pub/Collateral/NCP81174-D.PDF
Apparently the mosfet driver chip fails by turning on the lo-side mosfet simultaneously with the hiside mosfet, thus taking out the weaker of the 2.
I CANNOT TELL YOU how GOOD your content is ... and more importantly, how SUPERIOR your educational value is to anything I've seen.
I paid 15k for electronics school and I learned more in this video than I did in 2 years at school.
Dude, this is epic. I never knew it would be such an emotional roller-coaster. Haven't watched to the end yet but I'm rooting for you
I am watching you solder at 2am and find it fascinating. Love your videos 👍
I’m watch these every night before I go to sleep. Wonderful info!
YOU ARE REALLY AMAZING. MY REGRET IS WHY I DIDNT FIND YOUR CHANNEL EARLIER!
A GOOD CRAFTSMAN ALWAYS SHOW HIS MISTAKES SO WE ALL DONT MAKE THEM! YOU ARE EXCELLENT EXAMPLE! REALLY LIKE YOUR TROUBLESHOOTING CYCLES!
Oh yay! I just watched the ghetto fix and was hoping there was an update video, and behold, here we go! Thanks again for the great content!
Please try to do it you are the best guy explaining well throwing out lot of knowledge and experiment
Thank you for the details and explaining clearly how all this works. Very helpful. Would like to see more.
"It's Turbo dead! Ohhh Nooo" thank you, thank you, Thank You!!! I will be bogarting this quote over and over. Thanks for being human!
I really like your channel as you don't floss over problems but show everything warts an' all, well done keep it going.
Bravo, Graham! Super informative and entertaining.
That was really entertaining. Shame it didn't turn out as you hoped but hey, after all the replacement surgeries and explosions you still got it to work. That's a big win in my books. Keep it up! :D
I would guess the driver chip was turning on the high side and low side at the same time common issue with switching supplies
I have tried these MOSFET replacements and failed each time. But I never tried to dig that deep and improvise. Thanks for very interesting video!
Great video & with a great deal of patience, well done :)
that was crazy long and so educional video ! Respect for making videos like this to people understand little more more stuff :)
Love your determination and commentary.
thank god for these videos. I have a evga 960 that had a similar meltdown, Inductors exploded and it shorted, and the fan bearing blew out. the blue pcb burnt to a brown color. hoping it didnt destroy the traces in the pcb, that will make this repair a thousand times harder... But i wanted to try and practise repairing components. And this video was exactly what i needed! thanks a bunch!
Lol i did the same thing you did too! I plugged the 960 into a lower wattage psu, a 550 and it took power and fan kicked on, just didnt produce an image.. so i tossed it into my system to be faster with troubleshooting and plugged it into a 850w and suddenly i smell a burning smell, the fan is twitching and came to the conclusion my 850w surged into the card and fried a bunch of stuff.
I always watching your videos, and thank you that u mentioning the degree Celsius of hot air.
Make more videos where here and waiting and starting learning
Great video. Know how buck converters work, but never though about how they're used for multi-phased VRMs. Thanks for the education.
Man you are the teacher I never had🤗
Thanks for your videos. I'm really getting interested in electronic boards and their components now :-)
I did learn a lot from this video, thank you.
i learn a lot with this Honest vlog.... i'll continue watching and leaning on you vlogs....
'Honest' is a very apt word. He shows his failures and mistakes, not just his triumphs.
Brilliant! Loved this video!
Thank you for the interesting lesson.
I watch your videos like i watched The Shawshank Redemption or other great movies :))Imagine in high school i was the electronic class and none of those teacher talked like that and was so boring.Now...i watch with big curiosity, you explanation are so good and i understand no matter if my english is bad. :)) GOOD JOB!
Thanks very good and nice video I learnt so much from you.
Brilliant info - really useful and educational... many thanks for taking the time to share.. Subscribed ! :-)
Thank You.
And yes, learned alot (and I was sure I knew everything🙄). I enjoyed the magnum length video version. I ordered a pizza and told my GF to get lost. OK, I didn't do that.. I just let the air out of her 🤤 Anyhoot, you fought the good fight. Think I will pickup one of these classics. It will feel like an old trusted friend.
Cheers
🇺🇸😁🇬🇧
The fuck
Interesting look into buck regulators. The only thing you didn't try was swapping out the driver i.c. I think that was faulty (thermally unstable) and provided the path to ground for the high side f.e.t. The driver i.c. probably switched the f.e.t. on for too long, killing it.
50:20 i was so happy watching this moment your way of explaining things is amaizng
Thank you so much!
I really learned a great deal!!!👍🏼😎👍🏼
I DONT USUALLY STAY FOR THE LONG VID....but i was fascinated so I finished the video
Thanks for posting this video - I learned a lot :)
id love to see you fix some rx 570s an 580s i have a bunch i could send u man, i need fixed, but to see u do it would help me fix mine i love how u go over everything an explain it, SO AWESOME MAN i love you!!
I like your videos very much. Your speach is 98% understandable for a non native, non supreme speaker :) You can teach me electronics - in English! - That is way more rare than you may think...
Very good try. I really enjoyed this video. Thank you.
Really enjoyed this video. Thank you.
Very nice video. I learned a lot I found an ATI RX series card in my closet going to try and fix the short with my new machine.
Thanks for another great and very interesting video ! ;)
Terrifc video learned a lot . I am playing around with some ebay failures , Looking into reflow if no obvious failures.
I dont have a desk top pc. Mostly laptops I own.. but as a electrical technician.. this Is informative and interesting to watch
On top of the great content in your channel, I love your English! 👍👍
Agree
Boy, (i'm 63) you have done a good work. It will be that you not have fixed the phase, but for sure you have teached something of english to me!
So very interesting video. Very educational.. i injoy watching.
Fantastic video!!!
Been at NorthridgeFix , felt guilty so checking in. 😂😍
Thank you for the amazing explanation
Thnx for sharing knowledge... u are great man
I love the cheap compact testers/o-scopes. However in this case I'd love to see a decent analog scope, at least in an educational video. Just constructive criticism. Nicely done though.
True that, he's getting confused a lot just because the scope is limited and doesn't show properly what's going on.
I think he should see full 12V on the mosfet output, mosfet is either off - 0V or on - 12V, it should not show anything in between.
@@Arek_R. That's not actually true, with such high switching frequency you can't constantly hold 12V or 0V at the output, I will always be something between. And for such purposes there will be no difference between cheap and professional o-scope, only slighly change in readings accuracy. Personally I use ad1102ca from Atten which isn't either cheap or expensive, but didn't notice difference when compared to cheap ones or some high end for thousands of $ ;)
The difference isnt accuracy. The sample rate / memory depth, determine what can be displayed on the screen.
Good work, respect chap
Love the videos very educational
SUBSCRIBED! Keep up the good work and Thank you for this information! :)
Wow, this came full circle! Good info though!
Very interesting video!
More please !
Nice work mr. !
Graham bro, you are really awesome.....
awesome video! ive got an rx480 im trying to fix and this is super helpful.
In my experience (not specifically related to graphics cards), if your MOSFETs short, you should assume the drivers have been damaged and replace them as well.
I have a GTX 970 looks like liquid damage , short out PC . Happy to post it for a attempted diagnostic video
Great demonstration of how buck regulators work in real life. 👍👍👍 After theoretical explanation in a couple of previous videos it's nice to actually see it "in action". 😊😉 Thx for the effort.
Killer video, good info
Another great informative video, please Sir keep them coming but also please don't endanger the lives of yourself or your staff
Still, a great vid. I had no luck trying to replace a broken off 3.0 USB header pin on an older ASUS mobo, by desoldering/soldering (plan was to us a leg from a LED) but still felt satisfied with my effort in trying.
Great video.
Amazing video keep it up
Great vid!
"the short magically disappeard" :D There's no magic, the problem lays in the method you use to solder the mosfets (or actually any QFN-type components with thermal pads), placing to much solder on pads and then trying to push it out is a bad idea, 'cause you push it in all 4 directions, 3 visible and also the one that goes to G and S pads of the mosfets which you can't see but for sure will make a short circuit ;) So in my opinion it's better to clean the pads from old solder and use solder paste (even some cheap chineese one), SnPb is preffered (by me) 'cause of lower melting temperature :)
@1:09:40 you start thinking why it shorted again and burn upper mosfet while it has no connection to GND, it's all caused by failed PWM controller and/or driver which drives low side mosfets constantly so at output you have GND all the time and when swiching upper one it simply burns out ( double lower side mosfets can handle that short, single upper one will blow up)
How can you be so cool?! Thanks Sir!!
man youre amazing i love you
great content. thanks!
Good video 🔥💥💥
Forget your Kyles, Jayzs and Linusus.... This real IT problem solving! I wouldnt attempt it myself though... My clumsy fat fingers wouldnt be able to be this precise
I'm a retired electronic tech from the USAF and I've seen a capacitor test good but then go short. Replacing the capacitor corrected the issue of a system blowing a fuse. I'd say replace the Q1 cap even if it tests good.
you have exactly the same multimeter as me xD
Man, I'd love to work in a repair shop with you, haha
I find it funny that right after I left the video and commented you need to read schematics, you start looking at schematics.
Albeit not the card manufacturer schematics.
I wonder why? Also critical because the phase ground didn't end there, couldn't you have traced it farther?
I do understand though you showed how you can figure out without schematics what goes where, which is handy if it is obscure or old, but that card wasn't either.
Can't you get small business loans to cover ultrasonic cleaners and Schematics websites?
I can't find them for free but idk.
Thanks, this was awesome! I learned a ton. Entertaining as well.
Superb!!!!!
Please use Flux and see the magic how your soldering will be ! For soldering and desoldering use Flux please ! Very good informative videos I am so thankful to you for your effort and work!
Best regards,
Sir, it's 3:48am in the morning... WTHECK just happened.. all I heard was turbo dead.. Mosfett just dropped dead!!
😂R.I.Pieces Mr. Mosfet.
Sorry sir, I was quite happy for your accomplishment. Use the donor card.. what else can work as an inductor replacement?
Dr. Frankenstein we need an Abby Normal Brain.. A better Mosfet that can handle a fuller load. This way the resistors can still take care of some of the flow.
Im glad i found your channel mate. Great content and easy to understand even for someone that have no idea what the hell are you doing xD aka me )
Lovely bro
I like your way keep going on :D
It's hard to imagine it's worth your time to attempt to repair a 960 board. I don't know about the U.K. but a board like this is worth about $150 functioning, it seems like too much time and effort for not enough potential reward. Anyway, I really enjoy your videos, keep them coming!
Why is C160 backwards on the card?
3rd LFC video and i learned a lot already.. subbed!
Why this youtube only recommend your video just now?
at the start of page 13 of the datasheet at 21:57 sec, it's clearly written "if a phase is unused, the differential inputs to that phase's current sense amplifier must be shorted together and connected to the output"
Well spotted - that might've been the purpose of the resistors around the unpopulated driver chip.
Nice channel mate i subscribed!
aewsome dude, keep it raining...
If you have time a nice video would be one where you show how to test each item and what it should look like if it is good. I have several bad video card that I purchased trying to learn. I took a power supply and put 5 volts and 1 amp into the back video card 6 pin plug and tried to follow where the voltage stopped. I jumped the mosfet gates with 5 volts to try to get the mosfet to turn on, and in spots it did. Ground on one side of caps but got no futher. A video starting at the 6 pin and checking each item saying what you should see and what you did see moving along would be great. You know what things should read and jump right along, but a video for more or less beginners step by step would help alot of people I am sure. Thanks for your time and videos.
cleaning with isopropyl alcohol will help a lot and I believe that part that you did not know what it did is some kind of a boos or buck converter for voltage depending on the configuration.
well made video
These two pcb's are absolutely identical, I bet down to even a single wire and its physical pos. on the pcb, so it is highly unlikely that that you couldn't take any individual part and exchange it between the two pcb's - with only one exception - if the two boards has significantly different timing specs.
Just about all semiconductor manufactorers have don those designs since the mid 60's and Intel, AMD, Realtek and yes Nvidia and ATI too - you get a complete design with schematic diagrams, BOM and most often even Gerber and drill file.
I once had a collection of 8 different MB's that original was a Intel BX-440 - only difference was the color of the solder mask, occasional different color of a connectors plastic (never the position) and the top silk screen that stated the name of the OEM - as I remember ASUS, MSI and First apart from Intel, I can't remember the last four :-)
They were carbon copies of each other - except from major build quality variations ;-)
Thank you
Hi I am loving your videos on repairs keep them coming.
How ever it is not really a VRM, that term was used when the voltage regulator was on a small pluggable module, hence Voltage Regulator Module.
I am guessing the the topside FET is not switching properly maybe the bootstrap capacitor or driver IC is not working properly.
The input inductors are only for EMI reduction, if they were not fitted and it went short all that would happen is the PSU would go into chirp mode assuming you do not have any other components in the board that would fail 1st.
I believe the weird chirping you saw on the scope was a sign it was not switching correctly, and the waveform on the output of the FET will be a pulsed one from GND the 12V, I am assuming your pocket scope cannot display the correct waveform.
Question is.. have you tested the coils which the mosfets are working together with? If they all have the same characteristics to different frequencies, or if other components have measured values slightly off specs. It's a longshot, but it might be the cause of why it's the first mosfet that shorts, if the harmonics might be off tune causing standing waves, or if some other component interferes.
I was thinking, maybe you could trick it into running 2 phases instead of one at lower and moderate load to smoothen the transition to 3 (or 4) phases?
I really enjoy your videos and your waffling :)