Asus Crosshair VI Hero QCODE 8 no post

[artesano1969]

Hi all

I'm trying to get this board back to life. It came with minimal damage -a missing inductor and three socket pins broken; all is now repaired and checked.

However, it is not posting. All I see is qcode 8 (not 08, just "8") in the upper display.

I've checked all voltages, checked the BIOS chip, tha various xtals... The CPU itself is fine, as I have other boards for testing where it works ok.

Any clue of where a "qcode 8" may come from?

Many thanks!

Pablo

[artesano1969]

So, I've built the USB005 and check VRM which is not reporting any issue. However, I can't check its firmware because I don't have another source. I'll try to get one and report back, just in case I find something else. I've read qcode 8 is related to CPU power delivery, but it does not looks to be the case. I just want to rule it out.

Meanwhile, if someone comes through this thread and can share any info, would be very welcome.

Best regards

Pablo

[McKey]

Hi Pablo!
How can you repair broken pins? They were just bent?
And just to be sure: Did you reseted the bios? Voltage on the coin cell? Did you tried to remove the cell?
Miki

[artesano1969]

Hi McKey,

Well, a couple of them were slightly bent, but two more were broken and I decided to try to swap them with new ones rather than the whole socket. Using my DIY prehater, hot air station and precision tweezers I went ahead and successfully replaced them. This was my third attemp -I tried the same in a couple of occasions in older motherboards and the removal works always well...but I cannot say the same about putting the new ones in.

Best regards

Pablo

[McKey]

Im wondering how he did this:
https://youtu.be/dgNRJuzMan0

The exeact heat, airflow and the used solder are missing to pull this trick...

[artesano1969]

Hi McKey,

I use to set my preheater to 220°C (hot plate temperature) but given that it's a custom artifact this indication will probably not be very useful. In my case this tipyically yields around 160°C depending on the motherboard (my hotplate is made up of four heating elements, each delivering max. 600W, and a single temperature controller).

On the hot air station I use 320°C at 25% airspeed with 1cm nozzle (angled type, to be able to see what I'm doing through my magnifying glasses).

You may need more heat for power or ground rails.

Before soldering, I apply an small amount of low temp solder paste to the pin pad under the microscope.

I hope this helps.

Best regards

Pablo

[McKey]

Hola Pablo!
I just tested my low temp solder paste, it is advertised as 185°C paste, but the foxconn socket starts to melt before the paste. I will try more airspeeds. I have spare boards and sockets to test...

Back to the QCODE 8. Do you have a DDR socket tester? My CPU problems are often coming from bad traces to the DDR memory, so thats always the first that i check. What if you try it with only 1 dimm, and you switch that dimm around the sockets?

Regards,
Miki

[artesano1969]

Hi Miki

Unfortunately the board is not even reaching that point. It goes to qcode 8 without trying to check RAM; the same happens with no RAM at all. I bought a second non-working CH6 to compare to and, believe it or not, is affected by the same issue. It's neither the PSU nor the CPU as they work fine in other boards.

I've successfully read the firmware from both EPF036 and compared them: Exact match (and EPFs are working because I can read them). Also desoldered the flash memories of both KB3720Q chips; compared them and, again, exact match -both KBs seem to work or at least present signs of life.

I've even read the configuration of the ASP1405i . In this case I found a difference but, as long as the second board presents yet another defect (it goes of one sec after powering on) I cannot conclude anything -I've got a thread about it, asking for a good omen to provide me with the right configuration, just in case.

I'm running out of ideas about what can cause the code 8. Next, I'll go for SuperIO chips, but I still need to investigate them and there are no datasheets available -I requested them to Renesas but no luck yet; I'm not a professional and I'm not pretending to be.

On the other point, about replacing AM4 pins: I got really low temp solder paste from Aliexpress (138ºC and 158ºC respectively) and I don't think they make a lot of difference in this use case, because the pad is so tiny. I do it because I tend to over-engineer things :-) Probably the unleaded solder left in the motherboard pad will not care at all about whether the pin pad has low temp solder or not! It will need somethig to help sticking in place, but that's all.

In any case, my advice is to test in low value boards as usual. For me, the most difficult step is inserting the new pad correctly in place, because I'm not using a microscope and my hands are not what they used to be.

Best regards

Pablo

PS.- I'm looking for a working CH6 to be able to measure every single pin in order to diagnose my two failed boards. I'll then extract all the firmware again and will post it here just in case someone needs it in the future.