GTX 1080 Ti repair - Page 1
Forum section: electronics / repair

author: maggi373
author_rank: Contributor
timestamp: September 01, 2021, 12:27:40 am
content: So i did AIO water cooling on my msi gtx 1080 ti gaming card and wanted to use my pwm fan controller on my fans for gpu and not use motherboard or software. Meanwhile i waited for the 4 pin gpu fan connector to arrive in mail, i just soldered some wires on the backside of the connector directly. And this worked fine for a month and here we are today. I got a new sound card put it in and well a wire broke loose while i was mounting it. The pins for the fan connector is really small, so the wire didnt have much to grab on. Only noticed the wire after install and fans at 100 percent while in windows since i ran an custom fan curve via msi afterburner, it was rpm wire that got loose. I tought no worries, i just resolder it and i did. When i turned on the computer again i got no screen and i turned it off and on again then i smelled it. Daamn, i only soldered the pwm and rpm sensor cables. Ive been looking for visible damages but only found that D4 next to fan header had a indent circle on top so it might be blown. So i get no output for monitors but the system boots to windows with it plugged in but theres no igpu. I think i tried to connect an dp cable into it while booting after fixing the loose wire and heard an spark noise.So far i have soldered off D4, wich is an SOT-23 like package. Text is W** P9 probably WCM but its unreadable. Only shorts that could have happened is between pwm and rpm or rpm and 12v on the header, with my interference, pcb was clean. the sot package has its Pin 1 is connected to rpm and pin 2 is on pwm. the other side with the third pin goes to an controller it seems. I will take off cooling again tommorrow and take high res pictures at the same time, really late here. I need help with troubleshooting it, i really need it to work since i dont have money to get a new one. There is only 4 ohms between pwm and ground, wich is low, but nothing around the D4 nor the D4 itself is to blame for this.

author: maggi373
author_rank: Contributor
timestamp: September 01, 2021, 05:09:25 pm
content: So the fan connector is delivering an 12v output and i tried to check if there was any pwm but the oscilloscope didnt show any but it might be the no fan speed feature of the card. The gpu is reconised in windows btw, checked with another gpu connected. So i think i might have fried some compentents that is delivering video. I was able to cyptomining on it tho.

author: testpoint1
author_rank: Frequent Contributor
timestamp: September 02, 2021, 01:56:11 am
content: I think maybe your cooling system is in malfunction, you said the pin "Fan_PWM" to ground is 4 OHM, it was broken, actual value is 0.6V for the fan (Fluke F87 meter, red cord to gnd), 0.4V of PCB; please check the attached diagram, if D4 also broken, that means the 12V already from your cooling system to D4, that will destrory the circuit concern to NV3V3. now the bit coins seems the price is increasing, you may consider to buy a used RTX 2080 card, about 800 USD, the power consumption will low than GTX 1080 TI (about 20%), but the performance will higher than 20% GTX 1080 TI, if you are in US, you can buy one from me, I will give you one month warranty.

author: testpoint1
author_rank: Frequent Contributor
timestamp: September 02, 2021, 02:07:06 am
content: repair procedure:1. disconnect your cooling system, use a common fan instead of it for test;2. desoldering D4, check the NV3V3 short status, if that is in short status, it is hard for you since it has 56 pins, attached;3. if NV3V3 no short, power on to check if that is OK, if not, may exceed your capability.

author: maggi373
author_rank: Contributor
timestamp: March 06, 2022, 01:41:37 am
content: i checked several times to see if i got response, and when i was going to remove this post i saw your reply, didnt get email either. work done before i saw your reply today, D4 was fine even with the blob on it. But i have confirmed that there is an short for power to bios. I remember that it sparked when i put in my monitor during boot and the magic smoke escaped. With the thermal camera it looks completly fine except for the short showing, and i measured the pwm ciruit and couldt find any problems, going to check nv3v3 tommorrow. didnt have enought time today to do more work.

author: maggi373
author_rank: Contributor
timestamp: March 06, 2022, 01:49:28 am
content: ok, im kinda bored right now, too awake for bed, going to drive back to my lab, its 10km from my home and do some measurements and get the sd card with the pictures

author: maggi373
author_rank: Contributor
timestamp: March 06, 2022, 01:52:34 am
content: an unfocused thermal picture of short

author: maggi373
author_rank: Contributor
timestamp: March 06, 2022, 03:22:16 am
content: R291 and D4 has been checked fine, and with d4 desoldered there is still 4 ohms to ground and short with diode test with red on ground. Also the short on U2 between ground and lx wich goes to L1. but, new devolemt, while i took pictures with the thermal cam and showing some parts on the card turning on, it does not anymore. now showing only heat at r1039 to u4539. 0.1ohms of both sides on l1 and 0v with diode on lx on u2