A8N-E DEAD after Hypertransport and Voltage

[klau1]

Hi, although I've been a long time fan and reader of Anandtech, this is my first post.
After getting sick of the noise level of my two 120mm fans I finally decided since I wasn't playing games lately, it was time underclock my Athlon X2 3800 @ 2.5GHz to something below it's default 2.0GHz.

I restarted into the BIOS, noticing that the "FSB" freq doesn't go below the default of 200MHz, I decided to down clock the Hypertransport from 5x to 2x, and undervolted my cpu to 0.8v. I did this after noticing that setting any setting below 1.1 v only results in 1.1 v. I tried 1.0, same, so I tried 0.9 same, then I realized that even if it was working properly, CPU won't get much lower without a MHz underclock, so I set 0.8v with Hypertransport of 2x, then all hell broke loose. The system fails to even power on, let alone POST. After Clearing the BIOS, taking out the battery, unpluged for 12hrs, same result. What happened?

 

[customcoms]

Underclocking the HT bus will not underclock the "fsb" frequency (i.e the cpu), only the ht bus (the one that runs at 2000mhz). You could have lowered multipliers. As for why the board won't power on, that you'll have to take up with asus...

 

[Zap]

Are you sure it's the motherboard that's toast? There has been some evidence that too large a disparity between core voltage and memory voltage can kill A64 chips.

 

[klau1]

I tried the Internal Multipliers, but unlike the Operons, the X2s are locked above and below default. According to you then, underclocking in only possible via "FSB".

Update on situation, Zap thats exactly what I thought didn't make much sense to me either. Though I'm not a pro, I've had plentiful of experiences in overclocking various components, some with more success than others, but never a melt down like this. So right after I wrote my last post, I decided to take out the mobo for RMA As I did that, I felt a heat wave in the back originating from the PSU..

At this pt, I saw hope, if it's PSU shortage, most likely only a PSU replacement is required, so I quickily took out my trusty old Antec 400 PSU retired from the Socket A days and tested it out on this mobo even though it didn't have the extra 4 pins for X2. Surpisingly it semi POSTed, only freezing at the POST (due to lack of 4 pins?) but definitely powered up. Then I took my original 939 Antec 380 PSU and just pluged in the 4 pins and jump started with GREEN to BLACK, turned on the Antec 400 at the same time and ALL of a SUNDEN, everything worked!!!! The BIOS fully POSTed and everything. Of course I was careful to leave my x1900's 4 pins and all other components unpluged to minimize possible risk of farther damage. So at this pt, it was clear that the Antec 939 380 PSU needed replacement. But just for kicks, I unpluged the Antec 400 Socket A, and completely plugged in the Antec 939 380 PSU, and everything worked AGAIN!

Could it have been dust shorting out some circuits that got shoken off durring this excerise?

 

[klau1]

just to clarify, the x1900 was unplugged only durring the first trial, after PREPOST powerup proved successful which included a msg from ATI x1900 saying the 4pins must be plugged for farther boot, the second trial included ATI x1900 being plugged in as well.

 

[Zap]

Possibly a short, but more likely between the case and motherboard.

 

[corsa]

klau1...why dont u just enable Cool & Quiet

 

[Madellga]

Get a better PSU, OCZ, Enermax, Tangan.

From my side, never had an issue with Enermax, using since 1999....

 

[klau1]

C&Q is enabled of course...

Isn't Antec more expensive/ higher class then enermax? I've had both PSUs before, however Antec was the first one I had capable of 3% voltage regulation.

edit: 3%

 

[Heidfirst]

Originally posted by: klau1
I tried the Internal Multipliers, but unlike the Operons, the X2s are locked above and below default.

not on mine they aren't ...
Above yes other than on an FX are locked but you can run lower dividers than the default.