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Mobo have many random bugs at BIOS starts

Level 8

Is here any REAL PROFESSIONALS that could help with this strange problem??? 😉

Mobo is Asus Maximus IV GeneZ:
(Insalled latest BIOS without needless "Intel Smart Response Technology" = 3402.)

Mobo is about 2011 and can’t be returned by the warranty. Also PC equipped with high performance i5-2500K and still now a very good PC and I dont really want to throw it away.

At internet I found more than 30 threads about some boot problems with this mobo, but not one of them don’t approach to my situation.

Maybe some REALLY PROFESSIONAL at ASUS MOBOs can help with this problem?

=== Already about 4 years this PC/mobo behavior have some problems:
- Some random problems at cold-start (power-on) - hangs at BIOS/POST (1st or 2nd POST picture, or inside BIOS, or at boot initialization), error codes more often: 92, b2, A2; rarer: b4, b6, 34; very rare: b7, db, 78:
92 = PCI Bus initialization is started
b2 = Legacy Option ROM Initialization
A2 = IDE Detect
b4 = USB hot plug
b6 = Clean-up of NVRAM
b7 = Configuration Reset (reset of NVRAM settings)
DB = Flash update is failed
78 = ACPI module initialization
34 = CPU post-memory initialization
- Sometimes, about in one third of cases of entering into the BIOS, PC hangs in the BIOS (Usually with an error b6. Do I change the settings or just view settings. Also it’s happened at a variety places - monitoring, list of built-in devices, Q – Fan, etc. I did not clearly notice any exactly relations.) With this hang up, subsequent reset does not helps, only a full poweroff shutdown is required and sometimes even a BIOS/CMOS/NVRAM reseting (clr_cmos or a special button on the mobos back). (Maybe CMOS/NVRAM faults and BIOS can’t read the settings from it?)
- For 4 years the number of problematic launches increased and number of good starts decreasing... that its more like the problem is not electronic (logical), but electric (physical/mechanical).
+ If BIOS/POST starting are passed and PC started to booting Windows - then at 99% of booting everything worked absolutely fine and stable.
+ Also stable works Windows SleepMode and getting out from the SleepMode – it’s never does not fail!
- With the exception of two problems that happens at overall stable Windows:
- The active recording to external USB drives (via USB2 or USB3 rear or front) at 50% of cases were hanging out the PC.
- Also sometimes PC hangs out at some different moments for about 1-2time at month.

== But a few days ago the problem got worse, the behavior become even more random, but overall number of effective starts Windows drops to about only a 5%!:
- hangs up at most of cold starts (power-on) at: before/at/inside/after BIOS/POST or with black screen;
- with Windows suggests to pass chkdisk – PC hangs at randomly at 3-4-5-9-40-50% of HDD checking;
- or if cancel the chkdisk – PC hangs at Windows at different times for about 1-3min.

=== Tests and observations (for 4 years it’s not the first attempt to radically solve the problem):
- Firstly I was trying to change components right in the PC case: graphics card, another PSU, different memory - it's dont give any results, the bugs/problems still present.
- In-BIOS Voltage Monitor displaying 9 voltages, but 3 of them have not changing even once: 5v=5.120v, 12v=12.096v, CPU PLL=1.799v (had not paid attention, maybe before those numbers was the same).
+ When I removed all components from the PC case, make "clean build,removed all secondary elements (cards, coolers, connectors to front panel, etc), and leaving only: [ CPU + CPU cooler + 1memory + SSD ] - the PC is become much more stable while booting the BIOS, chkdisk works longer, but PC is still hung out after 3-5min. But BIOS-POST now normally starts at about 60% of PC power-on.
+ At last test config I replace the keyboard&mice connected via USB2 (through a USB-hub built into a decent monitor) to a PS/2 keyboard – PC becomes even more stable - if it passes the start stage of BIOS POST, then the computer finally began to boot and stably works at Windows for any time! Overall percent of effective boots reached ~90%!
+ At 2&3 configs I run MemTest from USB-flash a couple of times and it does not show any problems.
But still several times there were hangs, usually after changing the settings inside the BIOS: b6, b7, 27, db, 78.

My hypothesis is - some component on mobo increasingly stronger starve of not enough power (power degradation):
- The lack of power is exacerbated by the connection of the entire bindings-peripherals-graphics card, fans, external USB (BT-transmitter, IRDA, etc.) - the power is not enough even for BIOS booting! PC is buggy and hangs as often as possible!
- If remove all the small addons - the power becomes enough for a more stable start and run BIOS, but power still not enough at active file load tasks like chkdisk and Windows (maybe it’s a disk controller? and/or USB cotroller? inside the chipset bridge?).
- With all device disconnecting and using only PS/2 keyboard, only built-in video, one SSD drive, without case fans - the computer runs stably, normally booting and works at 90-95% of starts! (hangs only sometimes inside the BIOS).
- When PC is starting - the BIOS query all components - monitoring power, temperature, rotation, etc. and request to all devices - maybe that's because at the BIOS stage and inside BIOS the most issues and faulty happens?.
+ As I already wrote, if Windows booted and worked >5min - then PC works absolutely steady for weeks – all key components works stable on maximal loads like 3D-games, archiving, etc – it’s means that the problem is not at CPU, not at memory, not at video cards, not at HDD controller and not at HDD themselves.
+ If Windows starts and works >5min - then also a SleepMode works absolutely stable – maybe because the problem mobo component was not completely de-energized??? – So, what components on the mobo are initialized at cold boot (PC power-on), but not reinitialized when PC wake up from a SleepMode???

Have you any other assumption of what is the problem is and how to resolve it???

I have some experience with mobo repair so I want to try to repair this mobo too. Can you help to find the buggy power element on the mobo???

Level 11
Maybe a dry, cracked, or cold solder joint somewhere on the motherboard. Be careful around eyelet joints because of the multi-layers.

Had an old abit am2 nForce MoBo that did "funny" stuff like some of the things your is. I had to re flash the BIOS every now and then. Don't know why but...... That's what fixed it for a while???? Maybe a blast with a heatgun on LOW or a bake in the oven if BIOS flash doesn't help. Also maybe fresh TIM on chipset/VRM's (if you can of course not looked at MoBo tbh).


> AMpndiode
I don't think that problem at joint, because as a physical element - joint changes only at 200-400*C and so cannot gives so many random problems. Joint just passes electricity or not. And at mobo starts/works there are not so high temperatures to change joint's behavoiur. Also mobo does not get any physical impacts/shakes that can change position/contact of a joint.

> Darkstalker420
TIM and even absent of TIM (Thermal Interface Materials like thermal grease etc) can't give so fast problems as hangs on BIOS/POST and then don't gives any problems at CPU/HDD high loads. This assumption is wrong.
The possbile problem inside BIOS-chip don't unswer to a question - why PC hangs at mass data copying to USB-drives and sometimes just at some different moments at Windows???

More like its a power degradation of some power elements that feeds the chipset/bridge which transmits the power for USB devices through itself... but which element exactly???

Also is anyone have seen the freezes Voltage values at monitoring (like 5v and 12v at this mobo)??

Level 9
"Mobo is about 2011 and can’t be returned by the warranty. Also PC equipped with high performance i5-2500K and still now a very good PC and I dont really want to throw it away."

Sorry cant help you but just wanted to say I have the same set up and the i5 2500k (oc4.6) and the damned thing wont die and good as day one!. Agreed dont throw it away and good luck 😉

Thanks dude 😄

Any new suggestions or at least answers to a questions???

Are anyone have frozen voltages values at BOIS voltages monitorings??