Asus B550-E Motherboard repair no power help. - Page 1
Forum section: electronics / general

author: abel2b
author_rank: Newbie
timestamp: March 05, 2024, 06:46:07 pm
content: Hi, I need help repairing Asus ROG Strix B550-E gaming board.Motherboard died after removing GPU for cleaning, after plugging all back, board is dead no lights on logo, edge leds, DRAM, CPU, Boot LED´s or Q-code display nada!PSU is okCPU tested on another board okGPU tested on another board okRAM also tested on another board ok.+5VSB on PSU okPSON on PSU ok+3V on F-panel power button okSUPER IO NCT6798D (pin 60 PWRBTN#) high/low okPU4000 regulator +3VSB_ATX okon PHD6000 header I haveSKTOCC# (3V) ok3VSB_ATX okI do not have 3VSB_SIO on pin 45 of SIO (NCT6798D), RSMRST# or SLP_S3 signal necessary to boot .I have B550-Plus, B550M-Plus. B550-F boardviews and all have same SIO (NCT6798D) but very different board layout and minor component differences from B550-E...I have an idea what's going on, but I don´t know what voltages are necessary in standby to make board ready to boot, and which coils on the board are responsible, I´ve checked all coils and didn´t find any shorts but like I said I don´t know which is which or who is supposed to be on while on standby...?So if someone can tell me what SIO and PCH must have standby voltages to boot or SIO power up sequence it would help a lot, also schematics and boardview would be apreciated...THX

author: thm_w
author_rank: Super Contributor
timestamp: March 05, 2024, 11:30:16 pm
content: Cross posted here:https://www.reddit.com/r/AMDHelp/comments/1b6vof9/asus_rog_b550e_dead_no_power/Please link in the future.You haven't mentioned it, but I'm sure you've already checked most of these:- cmos battery is good?- cmos has been reset?- BIOS image has been reflashed or verified? (if you have the tools)- PSU is "ok" but no mention of using another known good PSU to test the system?- No damage to the PCIE port caused by removing the card?

author: abel2b
author_rank: Newbie
timestamp: March 06, 2024, 12:58:00 pm
content: Quote from: thm_w on March 05, 2024, 11:30:16 pmHi, thank you, for response....- yes I installed new cmos battery and resest pin ...- I have tool to flash bios but I didnot yet because RGB Led logo should at least light up in standby upon powering psu via +5VSB- I believe PSU is ok, I tested on another system and is working fine- very close inspection does not shot any damage or bent pin on PCIE slot....

author: 50ShadesOfDirt
author_rank: Regular Contributor
timestamp: March 07, 2024, 02:58:04 pm
content: If I were troubleshooting this mobo, I'd have the user guide for it at hand, and I'd strip it down to just mobo, cpu, and ram, and work from there to figure out why it won't even POST. Everything else but p/s disconnected. I'd even put just the essentials on a bench/a-s mat (takes the case & components out of the way), if you have this environment.If mobo doesn't have built-in graphics, try some other (inexpensive) graphics card for video output, but keep it simple. The expensive graphics card may have some issue of its own (given that you pulled it for cleaning), and you don't want to muddy the picture with it in place.If still no joy, check mobo for swelling, blown caps and such.Plenty of internet sites out there for troubleshooting the mobo in a pure "bench-like" test setting, so they guide you further.Hope this helps ...

author: Messtechniker
author_rank: Frequent Contributor
timestamp: March 07, 2024, 05:08:15 pm
content: Sure you have connected the extra 12 V power connector?

author: abel2b
author_rank: Newbie
timestamp: March 15, 2024, 03:02:48 am
content: Hi, guys sorry for the tardiness, had some other work to do...Quote from: 50ShadesOfDirt on March 07, 2024, 02:58:04 pmYes I have plain bare essentials on the table nothing else.What you mean by user guide ?Quote from: Messtechniker on March 07, 2024, 05:08:15 pmYes I have extra 12V connector from PSU connected