MS6337 ver 1

[bugmenot]

I was given an MS6337 815 pro v1 motherboard from an old computer. The symptoms are the board will no longer power up (PSU does not turn on). I have tried different PSU's and the same result, PSU doesn not turn on.

I later found out the person who owned it said it stopped working staight after he tried a pin-mod on his coppermine celeron. (The celeron still works).
I examined the board and All caps on the board are fine the only slight damage I can see to any part of the board is a chip called "CET CEB703AL" by the cpu socket. What does this chip do, would it stop the PSU working.

[Gianni]

Re: MS6337 ver 1

The first picture is not very clear but if I'm not wrong the component you are talking about has a burnt corner.
This is a Power MosFet and it is a part of VRM feeding the CPU.
If the PowerMosfet is shorted, the main PSU won't start because it is overloaded.
You have to check it with a DMM.
I'm afraid probably also the PowerMosfet controller is ruined.

Ciao
Gianni

[Toasty]

Re: MS6337 ver 1

He's probably blown something elsewhere in the board. That MOSFET really doesn't look like it's blown or overheated.

The question you need answered is: After the mod a) it never worked again, or b) it worked for a while and then stopped.

If it's A, then he blew something in the board and it's probably in the layered traces. If it's B, then it may be worth investigating that/those MOSFET's. There are also many microscopic IC's in and around that socket. If any of them are blown, I'm afraid it's over.

Toast

[bugmenot]

Re: MS6337 ver 1

It's A, the board never worked again straight after the mod. So I take from that you are sayind a dead mosfet would not be the cause of it?
The mod was on the Celeron CPU but that still works, it somehow just damaged the board (the memory and everything else was not damaged)
The board will power on for around 1/10th of a second in a flash before it goes off again. I noticed it has 4 diagnostic leds and they just quickly flash as green red ,red ,red, which the manual describes as "early chipset Initialization". I need to find what a voltage mod to a CPU would damage on the motherboard first(I closely examined the Mofets and all the caps look in very good condition).

[Toasty]

Re: MS6337 ver 1

Yes, a dead MOSFET could be the cause, but them blowing in that short a time period doesn't make sense.

What makes sense is that he did something wrong on the chip and it shorted the input power to the CPU and took out one of the smaller chips nearby and/or it burned an internal trace in the board.

Is the CPU working with the mod? Or, did he he undo the mod and it still works?

If you can fix it for cheap, go for it. How much is your time and effort worth? For $40 you can get one off flea bay...

http://cgi.ebay.com/ws/eBayISAPI.dll...m=120404448671

Toast

[i4004]

Re: MS6337 ver 1

i have ms6337 le5 and i can do fet measurements on it(i won't be taking cpu from the socket, though)...
i changed all the lytics on that board except those near the cpu that were fine...all those chhsi's were marginal(not real bulging, though..just slightly increased esr)...but they did last over 6 years....and it didn't happen overnight..it took it more and more time to heat up enough to start working...



toasty is probably correct, chacnes are he burnt something while tinkering...
why was he doing that anyway?
to overclok it..?
gosh...yea

[PCBONEZ]

Re: MS6337 ver 1

Yellowed from heat maybe?

[Krankshaft]

Re: MS6337 ver 1

Yup looks that way or maybe it's residual flux.

That center pin is probably connected to the metal heatspreader on the back of the FET so if it was heat there is your conduction path.

[Toasty]

Re: MS6337 ver 1

Since he answered 'A' to my question in #3, I highly doubt there was any chance for them to get the least bit warm.

I remember reading about this type of mod many years ago and the chance for damage, to either CPU or mobo, was high. It is a speed hack for the Celery processors on certain chipsets that were found to be able to step up in speed (+500MHz) if you did the mod and were able to adjust some voltages in BIOS. IIRC it "fakes out" the mobo by telling it "I'm a 133MHz FSB CPU".

We're going back somewhere in the past 10 years, so this is fuzzy as I never did it.

Toast

[370forlife]

Re: MS6337 ver 1

Kind of funny that they had to mod the cpu back then to make it overclock that much, while today we are pushing our multiple core cpu's gigahertz's past their ratings.

[Scenic]

Re: MS6337 ver 1

I remember reading about this type of mod many years ago and the chance for damage, to either CPU or mobo, was high. It is a speed hack for the Celery processors on certain chipsets that were found to be able to step up in speed (+500MHz) if you did the mod and were able to adjust some voltages in BIOS. IIRC it "fakes out" the mobo by telling it "I'm a 133MHz FSB CPU".

We're going back somewhere in the past 10 years, so this is fuzzy as I never did it.

Toast

hmm... seems like what you described is what i did with my old celeron...
(but i found that out by "accident"... forgot to set the FSB back from 100 to 66MHz while playing around with different CPUs.. and that's when i started testing to get the 566MHz Celeron running stable at 850MHz..)

Celeron 566MHz (128k, 66MHz FSB, 1.5V, SL46T)

set the FSB to 100MHz and raise the voltage "a tiny little bit".. (to 1.55V or 1.60V)
-> 850MHz
set the FSB to 133MHz, raise the voltage quite much (1.75V to 1.80V)
-> 1133MHz