Evga Z390 Dark motherboard repair project / missing components - Page 1
Forum section: electronics / repair

author: mirco_the_machine
author_rank: Newbie
timestamp: March 03, 2022, 12:14:46 pm
content: Hi everyone,I have picked up this lovely Z390 Dark board, that unfortunately is missing quite a few parts. I don't know anything about it's history. I tried powering it on with CPU and a memory stick installed, but got no response to pressing the power button. The (diagnostic?) LEDs did light up in white when I bridged the PSU, and the green LEDs next to the white ones did glow quite dim.I took pictures as good as i can, marked and labeled the spots where parts are missing.Many of the missing parts seem to be caps and, with my limited knowledge, I would say are not crucial for the board to boot. I hope someone around here can help me identify what parts need to be soldered on at what place.I personally do not have much experience with, or equipment for soldering small SMDs. My plan is to let a professional do the soldering. If you can suggest someone in/around Germany, feel free to drop a comment or pm.Thanks in advance for any help!

author: mirco_the_machine
author_rank: Newbie
timestamp: March 03, 2022, 12:16:56 pm
content: imgs0

author: mirco_the_machine
author_rank: Newbie
timestamp: March 03, 2022, 12:17:40 pm
content: imgs1

author: mirco_the_machine
author_rank: Newbie
timestamp: March 03, 2022, 12:22:10 pm
content: imgs2

author: mirco_the_machine
author_rank: Newbie
timestamp: March 03, 2022, 12:23:48 pm
content: imgs3

author: TiN
author_rank: Super Contributor
timestamp: March 04, 2022, 03:58:38 am
content: Man, that board was murdered. Based on damages, might not be easily fixable.I checked some old photos, and here's the list from your labels (crazy work with labels lol, I'd just use paint instead)0. Q29 should be same as others nearby, AO3414 if I remember right. Those transistors are just for LED indication drivers.1. You can clean mess with qtip and 99% IPA2. 0 ohm 0402 resistor, one under it that's barely hanging is 1Kohm3. 0 ohm 04026, 13, 15, 16, 17, 18, 22. 100nF 0402 16V capacitor4. 0 ohm 04025, 12. 51 ohm 0402, I think board should still boot without those ones. Hidden pad nearby is for XDP port used for development only.8, 9, 10. 22uF or 47uF 0805 capacitor, same as one next to it7, 47uF or 22uF low ESR 1206 capacitor11, 20, 21. 3A 0805 inductor. kinda important one, gives power to chipset14. 10k 0402 resistor19. 6A 0805 inductor, also important one23, 24. I'd try 10k 0402 there, something to do with WiFi card25 had 100nF 0402 capacitor for high-speed USB3 bottom port. Now without pads you need to expose copper tracks next to former pad and doctor cap with thin wires to there. Easy to do but need a microscope and steady hands.Good luck with repairs. E399 board was fun project and first one where I rotated CPU + DIMM socket for cleaner layout and better power delivery. I was inspired on that from DFI NF4 LanParty's which were awesome overclockers in AMD days.Also check that BIOS chip is not stolen. Board will not power up without BIOS chip in place. Or you could flip BIOS selector switch to number 2 or 3.

author: mirco_the_machine
author_rank: Newbie
timestamp: March 09, 2022, 06:29:44 pm
content: Thanks so much for the information, I really appreciate your help. Gave me some hope for the board.What I found on Mouser so far:- 0: N-Channel MOSFET, ZXMN2B14FHTA (https://www.diodes.com/assets/Datasheets/ZXMN2B14FH.pdf)- 2 3 4: 0401 1/16 watt 0 Ohm, CRCW04020000Z0EDC (https://www.mouser.de/datasheet/2/427/crcwce3-1762584.pdf)- 6 13 15 16 17 18 22: 0402 0.1uF 16V, VJ0402V104ZXJCW1BC (https://www.mouser.de/datasheet/2/427/vjw1bcbascomseries-1762447.pdf)- 5 12: 51 Ohm 0402, 71-RCS040251R0FKED (https://www.mouser.de/datasheet/2/427/VISH_S_A0002273315_1-2568039.pdf)- 14 23 24: 0402 10 kOhm, TNPU040210K0BZEP00 (https://www.mouser.de/datasheet/2/427/tnpue3-1762586.pdf)- 19: 0805 inductor 6A,FBMJ2125HS250NT (https://www.mouser.de/datasheet/2/396/TaiyoYuden_chipbeads01_e-1274227.pdf)- 7 8: 1206 Tantal 22uF 16V ESR=2 Ohm, F951C226KSAAQ2 (https://www.mouser.de/datasheet/2/40/AVXC_S_A0011739185_1-2538296.pdf)Feel free to check, but I think the parts should be okay.Though, there are some parts where I'm not sure what to order:Quote from: TiN on March 04, 2022, 03:58:38 amregarding 9: I looks like there was a 1206 SMD on there. You wrote 0805. I guess it does not matter in the end, but what could matter, is the rated voltage. Does one simply use 16V everywhere except the Vcore-rail?regarding 10: how much rated voltage is necessary?Quote from: TiN on March 04, 2022, 03:58:38 amregarding 11, 20, 21: I think there were 0402 parts on these spots. I did not find 3A 0402. Do you think this would be okay?:https://www.mouser.de/datasheet/2/597/0402hp-270660.pdfQuote from: TiN on March 04, 2022, 03:58:38 amregarding 25: how much rated voltage is necessary?