Fix for M2-ATX and Jetway!

andrewb · 01-09-2007, 12:06 AM

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

Rillee · 01-09-2007, 12:42 AM

So i should replace my jetway board instead of my m2-atx, because im having boot problems?

Wiredwrx · 01-09-2007, 12:00 PM

Quote: Originally Posted by Rillee

So i should replace my jetway board instead of my m2-atx, because im having boot problems?

Sounds about right.

Michael

Ralphh85 · 01-09-2007, 12:51 PM

so what does changing C35 do then????? does it stop it from "overshooting"??

good to know what the problem is tho!

Ralph

andrewb · 01-09-2007, 07:56 PM

The C35 change on M2-ATX is addressing some timing problems, not affecting the Jetway issue....

Staritng next week all M2-ATX will also have C35 modified to 10nF. I will post soon the M2-ATX revision changes (minor).

Quote: Originally Posted by Ralphh85

so what does changing C35 do then????? does it stop it from "overshooting"??

good to know what the problem is tho!

Ralph

sajeev · 01-10-2007, 05:09 PM

I have the same problem with the jetway 1.5 and m2 psu. I bought mine from cartft.com few weeks back. If I send mine back to them and explain to them about the fix how will I know the new motherboard they send me wil have the fix on it?

Rillee · 01-11-2007, 12:43 AM

Quote: Originally Posted by sajeev

I have the same problem with the jetway 1.5 and m2 psu. I bought mine from cartft.com few weeks back. If I send mine back to them and explain to them about the fix how will I know the new motherboard they send me wil have the fix on it?

im also going to send back my jetway 1.5 to cartft.com. They told me too send it back in the end of January, and i will also get the newest version of the m2-atx. I hope this will fix my boot problems.

xcha · 01-18-2007, 06:36 PM

How do I know if I have a revised version or not? I bought three boards within the last month(dec 2006). I have these boot issues and now one of my boards don't even boot up bios. Please respond back with anything you know.

specs: m2-atx and 512 ram on jetway c7 board.

agiorgitis · 02-08-2007, 10:08 AM

I'm about to order a Jetway M/B and M2-ATX. How can I know if the MB is the new revision? What should i ask the supplier? (I want to ask him if it's the new revision before ordering it)
Thanks...

Kai · 02-27-2007, 01:57 PM

Quote: Originally Posted by 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 does this translate to in visible terms to the computer user? As in motherboard turns and does this, while that doesn't do that.

I have a Jetway low power and am wondering if that is the exact problem I'm having or not. The problem seems to have surfaced with freezing temperatures. It was fine before.

Motherboard will power-up
LED on
cpu fan goes on
BEEP
keyboard light goes on, then goes off....no keyboard power
vga screen does nothing....no vga power
motherboard continues to run LED and fan
USB CD-rom also appears to have power

Same exact thing or no?

diosagain · 04-19-2007, 09:51 PM

I am having the same problems except now I brougt the motherboard back into bench and its not booting at all. The fans turn on and the board turns on but their is no vga feed and its not turning on i guess. I really don't know what to do.

tom_rosenback · 05-19-2007, 12:56 PM

I have got a strange problem at startup also.

My configuration consist of a Jetway J7F2WE1G5D motherboard, a M2-ATX powersupply and a SATA hard disk.

When starting up the computer it doesn´t find the harddisc, if reset the motherboard with the reset switch the motherboard finds the disc and Windows starts up as normally...If I restart Windows it also finds the disc. Has this something to do with the earlier mentioned fix? Can anyone help me with this? BTW I have got the latest bios installed, v.9.0 at the moment.

// Tom

pirotlord · 06-01-2007, 01:28 PM

This sounds like the EXACT same problem I am having with my M2-ATX and a Jetway 1.5ghz mobo. It never wants to startup on cold mornings.

Who can I contact to have this fixed?

I bought mine on ebay so...

Is there a DIY kind of fix for this??

gibroni · 06-02-2007, 12:21 PM

So this means I'm not getting the M2. Any suggestions for another powersupply? I'd like to power a touchscreen with it too. How are the pico PSU's?

morris_the_cat · 06-02-2007, 12:26 PM

Quote: Originally Posted by pirotlord

This sounds like the EXACT same problem I am having with my M2-ATX and a Jetway 1.5ghz mobo. It never wants to startup on cold mornings.

Who can I contact to have this fixed?

I bought mine on ebay so...

Is there a DIY kind of fix for this??

You must have the exact same setup as I. I too would like a DIY guide or something. I figure I have until December to work on this when the weather starts dipping below 0C. On those days I have to restart it after the 1st boot try, i guess after it warms a little???

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