Help fixing Motherboard Asus - Page 1
Forum section: electronics / repair

author: leham
author_rank: Regular Contributor
timestamp: April 08, 2015, 07:12:16 am
content: Hi guys, so I recently picked up a ASUS P6x58-D-e sold as faulty.Basically this system will no POST.The seller said it just stopped one day..What happens is the board will power on, cpu heats up but the D-ram LED stays lit.Things I have tried;Resetting Timings RamOK! buttonReflashing the bios to latest version externallyvarious Ram sticks (from a working PC)Reflowing the north bridgeThe VRMS for both the CPU and Ram heat up

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2015, 07:37:11 am
content: Have kept a few old MB's going with new caps, pull a few and check values and ESR.Some are very particular to the flavour of RAM, the manual will state compatible types.Also move combinations of RAM between slots, that sometimes works.

author: Grapsus
author_rank: Regular Contributor
timestamp: April 08, 2015, 09:46:12 am
content: Have you tried attaching a buzzer to the motherboard ? Some boards are capable of giving some kind of indication even without RAM attached (BIOS starts with CPU cache as RAM).

author: SaabFAN
author_rank: Frequent Contributor
timestamp: April 08, 2015, 08:29:30 pm
content: Aside from a buzzer, also put a POST-Card into one of the PCI-Slots. ATX-Motherboards are sending 2 Bytes on a specific port during the POST, showing you at which point of the POST-Process there is a fault.Although from what you're describing, it seems like the RAM cannot be initialized correctly. Suggesting something to be wrong in either the routine that is initializing the RAM, a faulty memory controller (inside the CPU), faulty RAM, a blown RAM-Power Supply, or damaged connections from the RAM to the CPU (Damage to the socket, the PCB traces or the contacts inside the RAM sockets), or simply a stubborn Board.If something is wrong with the power supply, it might be fixable. If not, you probably wasted your money. Mainboards are very highly integrated devices. Finding faults that aren't obvious is next to impossible.Btw. Check the socket for burns. Idk if it applies to this board, but for about half a year Intel CPUs made for a specific socket could fail by burning pins on the socket.

author: leham
author_rank: Regular Contributor
timestamp: April 09, 2015, 07:01:58 am
content: it's a fairly recent board, being a 1366 socket it's BGA, the CPU is working as I bought it separate and it heats up.Could a reflow help?There appears to be a diode missing from around the ram, it's close to the CPU overvolt jumper but looks like it runs into a ram slot.The power section for the ram gets warm if left on for a few minutes.

author: leham
author_rank: Regular Contributor
timestamp: April 09, 2015, 08:18:26 am
content: I'm on mobile sorry, what about the chipset??Edit:Ok so I attached the buzzer and it makes not a sound..With no ram it gives a ram error, 1 long beep and 2 short ones..

author: nctnico
author_rank: Super Contributor
timestamp: April 09, 2015, 10:50:03 am
content: How about the changing RTC battery? If that is dead, the motherboard will also stop working.

author: leham
author_rank: Regular Contributor
timestamp: April 09, 2015, 11:13:04 am
content: Yeah tried thatWith a new one and with none at all

author: Grapsus
author_rank: Regular Contributor
timestamp: April 09, 2015, 11:44:05 am
content: Quote from: leham on April 09, 2015, 08:18:26 amThat's interesting. It might suggest that at least some very low level code gets into the CPU and tries to initialize the RAM. Since without RAM there is an explicit error and with RAM everything just hangs, we could speculate that the low level code initializes the RAM, then tries to access it and at that moment something catastrophically fails and disrupts the BIOS code. I'd make 100% sure the RAM module is working (use memtest86), then try moving it across several sockets, check RAM power for quality and finally check connections between the RAM and the chipset. The last step is probably impossible unless you work in a well equipped electronics lab and even then it would be too much trouble for a 50$ board.

author: leham
author_rank: Regular Contributor
timestamp: April 09, 2015, 11:53:33 am
content: This is a $300 boardWell acording to evilbay anyway hahaI'll have another poke around tomorrowAnother odd thing is the onboard power button (RED led backlit when off) turns the system on fine but the led does not turn off (I'm not 100% it does turn off when powered on)

author: leham
author_rank: Regular Contributor
timestamp: April 11, 2015, 11:51:55 pm
content: bump