andrewb

Looks like I was able to nail a problem with all the Jetway MotherBoards firing up with M2-ATX and possibly other types of PSUs, especiually at low temps.

Problem explained:

When a PSU starts up, some rails tend to 'overshoot', which is OK, if the PSU is designed well and if the overshoot is no greater that 5% on a specific rail.

Looks like the Jetway boards are really fussy on the 12V rail, during the startup sequence. If voltage goes over 12.5V at startup (BTW, within the ATX spec), the boards will fail to post, ESPECIALLY at low temperatures. Please note that this problem happened on only 5% of their motherboards, the rest work ok! (but enough to give us a huge headache)

While trying to find a fix to this problem I realized that this is a Jetway M/B specific problem. As we also distribute Jetway Morherbords, I called Jetway support. To my amazement, Jetway/Taiwan fixed the problem in less than 3 days! (Try this with VIA, hehe).

Voila, now all Jetway motherboards can now 'overshoot' the 12V rail and guess what... You can take the 12V rail up to 14.5V now. (do not try this at home).

What is also very impressive, is that we tested the Jetway M/B at -40Celsius and the M/B started every single time. We used a Half-Cube temperature test chamber, -40C is the max that this chamber can produce.

Starting Jan-15-2007, all Jetway motherbords will include this fix.

-Best,
Andrei