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[lAze_a55]

Check the capacitors on the motherboard for leakage, maybe one is faulty.

[DarkMatter]

@lAze_a55

QUOTE

Check the capacitors on the motherboard for leakage, maybe one is faulty.

The odds of leaky capacitors on two brand new power supplies is so remote, that it would never be considered as a fault.
By the way, how is he supposed to check a leaky capacitor?

@hubballi
Since you've tried 3 PSU's including the original, you MUST have a fault on your motherboard. There's a good chance you have a major short somewhere.
Here's one check you can make easily:
* Take the top cover off your X-Box
* Remove the hard drive entirely and try turning the unit on
* If it still doesn't fire up, then disconnect the ROM drive, then try again
* If still no result, place your ear near the PSU (not too close) and try powering up again. Listen for any ticking sound. If it does tick, then you have a motherboard short on one of the voltage rails

If all of the above gives you no results at all, then I can suggest other checks you can do, but you need the aid of a digital multimeter to do further investigation. Please let me know if you have one, then we can go from there.
Regards,
DarkMatter

[lAze_a55]

QUOTE(DarkMatter @ Dec 18 2008, 06:14 PM)

@lAze_a55

The odds of leaky capacitors on two brand new power supplies is so remote, that it would never be considered as a fault.
By the way, how is he supposed to check a leaky capacitor?

@hubballi
Since you've tried 3 PSU's including the original, you MUST have a fault on your motherboard. There's a good chance you have a major short somewhere.
Here's one check you can make easily:
* Take the top cover off your X-Box
* Remove the hard drive entirely and try turning the unit on
* If it still doesn't fire up, then disconnect the ROM drive, then try again
* If still no result, place your ear near the PSU (not too close) and try powering up again. Listen for any ticking sound. If it does tick, then you have a motherboard short on one of the voltage rails

If all of the above gives you no results at all, then I can suggest other checks you can do, but you need the aid of a digital multimeter to do further investigation. Please let me know if you have one, then we can go from there.
Regards,
DarkMatter

Hmm I don't know, actually think about what I posted instead of implying I'm a dunce. A: I said "motherboard", not power supply. I would not assume 2 entirely different brand new power supplies were faulty B: Maybe I didn't clarify well enough, but I was referring to an actual leaking capacitor, as in electrolyte seeping out of the cap. Unless your blind, spotting a "leaking" cap is fairly straight forward, ie bulging top of the canister or a substance at the base or top of the canister.

I know it's possible, cause I have fixed one personally. I'm not saying it will fix his box, but it's worth looking at since 2 new ps's neither work. Also are you 100% sure they are the correct power supplies for the correct version of motherboard. There are 3 variations after all and none are of the 3 are compatible with each other unless they are after market "universal" one's.

[Alex548]

Just throwing this out there. . .  is your motherboard a 1.6?
If so, you have a blown transistor on the motherboard and the PSU's are fine.

[DarkMatter]

@lAze_a55

QUOTE

Hmm I don't know, actually think about what I posted instead of implying I'm a dunce. A: I said "motherboard", not power supply. I would not assume 2 entirely different brand new power supplies were faulty B: Maybe I didn't clarify well enough, but I was referring to an actual leaking capacitor, as in electrolyte seeping out of the cap. Unless your blind, spotting a "leaking" cap is fairly straight forward, ie bulging top of the canister or a substance at the base or top of the canister.

I know it's possible, cause I have fixed one personally. I'm not saying it will fix his box, but it's worth looking at since 2 new ps's neither work. Also are you 100% sure they are the correct power supplies for the correct version of motherboard. There are 3 variations after all and none are of the 3 are compatible with each other unless they are after market "universal" one's.

My deepest apologies lAze_a55, you are absolutely correct. Stupid me kept thinking of the PSU's and not realizing you were talking about the motherboard. And when it came to leakage, I again assumed wrong. I thought you were talking about reverse current leakage.
Once again my apologies my friend.

@Alex548

QUOTE

ust throwing this out there. . . is your motherboard a 1.6?
If so, you have a blown transistor on the motherboard and the PSU's are fine.

Good point Alex548, it would give the same symptoms.

Regards,
DarkMatter

[lAze_a55]

QUOTE(DarkMatter @ Dec 19 2008, 03:18 PM)

@lAze_a55

My deepest apologies lAze_a55, you are absolutely correct. Stupid me kept thinking of the PSU's and not realizing you were talking about the motherboard. And when it came to leakage, I again assumed wrong. I thought you were talking about reverse current leakage.
Once again my apologies my friend.

@Alex548

Good point Alex548, it would give the same symptoms.

Regards,
DarkMatter

No prob! I was just throwin something out there to try and help him out and that was about the most experience I had was with the faulty caps. I didn't ever spend too much time trouble shooting into the electronics of the boards I modded. If I couldn't chip them to stop a frag then I just got rid of them and picked a cheapy from Ebay and tried again.

I've changed a transistor on 1 xbox and it was a 1.6. Well atleast I guess that's what it was. It was the small square chip with 3 leads right above the gpu to the left. I toasted it myself by accident by grounding one of the leads if I recall right. But as Alex said, that would definitely be worth looking at cause they can go fairly quietly and won't really show any obvious signs that they are the faulty component.

[hubballi]

Can anyone help ?

[Heimdall]

You're right - the serial number says it's a 1.4.

Just to confirm, you have a Conexant video chip, no GPU fan, and 2 rows of pins on your PSU connector?

I've always found that UnleashX (latest build only) and XBMC (all the versions I've ever used) get the version right .... but as your Xbox won't start that's no help!!

[hubballi]

QUOTE

Take the top cover off your X-Box
* Remove the hard drive entirely and try turning the unit on
* If it still doesn't fire up, then disconnect the ROM drive, then try again
* If still no result, place your ear near the PSU (not too close) and try powering up again. Listen for any ticking sound. If it does tick, then you have a motherboard short on one of the voltage rails

I have done all the above checks with still no power. Tried listeing to the PSU while powering up and NO ticking noise. I don't have a digital multimeter.

[hubballi]

Can you help me here Dark Matter ?  

[Alex548]

Is your power/eject board connected? Double check to make sure it is.
If you have access to another power/eject board, try swapping them out & see if that helps.

[hubballi]

QUOTE

Is your power/eject board connected? Double check to make sure it is.

Yes, it is plugged into the board.

[hubballi]

No.......................................................?

[lordvader129]

if you have another xbox try the power supplies in there, or if you have a PSU tester use that

other than that theres not much to say, other than you might need to replace your motherboard

[DarkMatter]

QUOTE(hubballi @ Jan 6 2009, 07:24 PM)

Can you help me here Dark Matter ?  

Do you need help in identifying the model of your X-Box or how to fix the PSU?
If its the model number, then its a Version 1.4.
If you need help with trying to find out what's wrong with the PSU, then you need a digital multimeter. Any checks will be impossible without one. Sorry about that.
You can buy a cheap digital multimeter from Radio Shack.
Regards,
DarkMatter