I am currently trying to fix a blown xbox SMPS, that has shorted after
someonen split coke into the unit.

I found it had a blown MOSFET which has been replaced. I have checked
all the transistors and diode and the they all seem to be fine, an no
obvious signs of blown resistors or caps.

There is also a few IC for voltage regulation, but am having a few
problems trying to find info in regards to them.

Since the PSU is effectivly an ATX PSU, what is the next step???

I haven't checked any of the coils, and would not expect them to fail. I
have been using another (also) faulty psu to compare parts readings. The
other unit just failed, no blown MOSFET, but still doesn't power up.

I was thinking it could be the optocouplers, but do these fail????, and
how do you test them??? A diode test on the pairs seem to test fine.

Any help appreciated.

Thanks

TEX

"TEX" wrote in message ...
I am currently trying to fix a blown xbox SMPS, that has shorted after
someonen split coke into the unit.

I found it had a blown MOSFET which has been replaced. I have checked
all the transistors and diode and the they all seem to be fine, an no
obvious signs of blown resistors or caps.

There is also a few IC for voltage regulation, but am having a few
problems trying to find info in regards to them.

Since the PSU is effectivly an ATX PSU, what is the next step???

I haven't checked any of the coils, and would not expect them to fail. I
have been using another (also) faulty psu to compare parts readings. The
other unit just failed, no blown MOSFET, but still doesn't power up.

I was thinking it could be the optocouplers, but do these fail????, and
how do you test them??? A diode test on the pairs seem to test fine.

Any help appreciated.

Thanks

TEX


Check for resistors that may have opened, particularly the dull ceramic
looking flameproof resistors.

Apparently the unit is tuned based on parasitic capacitance of some of
the components. Hence the difficulty in tracing down the fault.

http://www.delta.com.tw/products/pow...N-96AP%20A.pdf

Others have tried, but failed, hence the large number of ppl selling
replacement PSU's on the net. How do ppl go about fault finding with a
design like this???

Thanks

TEX

James Sweet wrote:

"TEX" wrote in message ...

I am currently trying to fix a blown xbox SMPS, that has shorted after
someonen split coke into the unit.

I found it had a blown MOSFET which has been replaced. I have checked
all the transistors and diode and the they all seem to be fine, an no
obvious signs of blown resistors or caps.

There is also a few IC for voltage regulation, but am having a few
problems trying to find info in regards to them.

Since the PSU is effectivly an ATX PSU, what is the next step???

I haven't checked any of the coils, and would not expect them to fail. I
have been using another (also) faulty psu to compare parts readings. The
other unit just failed, no blown MOSFET, but still doesn't power up.

I was thinking it could be the optocouplers, but do these fail????, and
how do you test them??? A diode test on the pairs seem to test fine.

Any help appreciated.

Thanks

TEX



Check for resistors that may have opened, particularly the dull ceramic
looking flameproof resistors.

Others have tried, but failed, hence the large number of ppl selling
replacement PSU's on the net. How do ppl go about fault finding with a
design like this???


That's Microsoft for ya! :-p - Reinhart

"LASERandDVDfan" wrote in message
...
Others have tried, but failed, hence the large number of ppl selling
replacement PSU's on the net. How do ppl go about fault finding with a
design like this???


That's Microsoft for ya! :-p - Reinhart

Microsoft didn't design the power supply, they outsource that sort of thing.

That's Microsoft for ya! :-p - Reinhart

Microsoft didn't design the power supply, they outsource that sort of thing.

Exactly. They probably outsourced with a company willing to accept the lowest
bid. - Reinhart

"LASERandDVDfan" wrote in message
...
That's Microsoft for ya! :-p - Reinhart

Microsoft didn't design the power supply, they outsource that sort of
thing.

Exactly. They probably outsourced with a company willing to accept the
lowest
bid. - Reinhart

Probably, it's called business, every successful company does this. Name one
piece of consumer electronics gear that's designed with field serviceability
prioritized over lower cost.