Overclocking 1700+ on Soyo KT400 Ultra Platinum

I have heard all the wonderful thing about the AMD Tbred 1700+ but having trouble getting it to run at 166MHz.
My friend has an AXDA1700DUT3C, I myself have an AXDA2000DUT3C. We both have the Soyo KT400 Ultra Platinum boards. We have tried many setups but could not get them to run at 166MHz (we want higher though).
We tried with Antec 450W PS, Kingston HyperX PC3500, Thermaltake Volcano 7+, ...
Any idea what's the problem that we are having? I am suspecting the Soyo board but I saw other people with Soyo got their 1700+ running at 190MHz. Could it be the new BIOS? I have flashed them with the new 2aa7. I will probably try the older BIOS to night but want to ask to see if any of you guys might know the answer. Thanks.

if you could give us some more info on your 2 cpu's data...
full reading of the steppin AIUHB/JIUHB 0230 (yearweek) of those chips, along with your mem modules, (generic/maker) which memtimings are you using currently and what are your cpu's running at this time?

Welcome to the Forums

Have you tried increasing the CPU voltage any?

Have you set the AGP/PCI bus divider in the BIOS for 166 FSB speed? It might look something like 5:2:1.

Yeah my friend hit 190FSB but he has the chip unlocked and had to play with the dividers and ram settings. Just be patient and try a bit @ a time. Good Luck and wecome to the forums.

Thanks for all your responses.
I am at work right now and don't have all the reading here with me. We bought the 1700+ from NewEgg and at the time, I checked the reading and it is a Tbread B with a built day like 031x. We tried all sorts of memory. At first we used Nanya PC2100, then Samsung PC2700, then Kingston HyperX PC3500. I don't think memory is the problem because the last memory we tried is the Kingston HyperX PC3500 which supports CAS 2 and we set the memory timings at the slowest setting (2.5-3-3-7).
We used Antec 550W PS so it can't be the PS either. I think the default voltage on both CPU are 1.6V. I have pumped it up to 1.725V just try to run it at 166MHz but it would not boot into Windows at all. 160MHz will failed Prime95 in about 5 minutes.
I have tried flash the motherboard back to BIOS 2aa5 (the newest one is 2aa7) and still have the same problem. I am suspecting the problem is with the heatsink. We used Volcanos 7+ but previously we used the Soyo utility tools to check the temp and it does not show the correct temp. The Soyo tool always showed below 42C but the temp in BIOS showed around 51C. I did not think about the heatsink because we used the Soyo tool and it showed 42C + Volcanos 7+ supposedly supports 3500+ (as claimed on their website), we also used that grease called something Silver III. It could be that I used too much grease. I already ordered the SK7 and it should be here next week. Will try again with the new heatsink but I doubt the problem might be with the motherboard.

Just to be more specific, here are the steps that I go through:
1) Machine has been off for at least 12 hours (CPU is cold).
2) Turn it on, go right to BIOS.
3) Change "System Performance" to the lowest setting: "Normal" which I believe setting the memory timings to 2.5-3-3-7.
4) Change "CPU Frequency" to Manual and enter 166MHz.
5) "CPU to PCI divider": either automatically changed to 5 or I will change it to 5.
6) Change "DRAM clock" to 166MHz
7) Change "CPU Ratio" to 8.

Save BIOS setting and let it boot.
Can't boot into Windows.
Go to BIOS and change the CPU Frequency to 160MHz.
Boot into Windows but fail Prime95 in 5 minutes.

I really wish I had an Abit to try.