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Old 08-17-2011, 07:10 AM
bluemimmosa bluemimmosa is offline
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Question Modifying a xbox360 PSU with input 110v to work on 220v.

hello, i have a xbox360 that i got from US, and with that i got a 110v input AC power supply unit. but since i dont have a 110v converter or i dont want to make it a part of the xbox360 system, i am hoping to convert the power supply unit to work with 220v. After opening the PSU, i found two varistors each labeled for 110v, so i removed them and, then plugged into the 220v line and it worked great. But after 15 minutes of playing, my psu got a blown noise and now dead, i opened and looked it again, and found that, the PSU fuse was broken, so i replaced it with high ampere fuse and plugged it in, but it exploded loudly this time? so my question is what we need to do to convert a 110v input psu to 220v input psu.
Thanks in advance.
best regards.
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Old 08-17-2011, 07:23 AM
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Kermit2 Kermit2 is offline
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At this point you will need a new AC power supply unit. Putting a bigger fuse in equipment which blows a fuse is ALWAYS a big no-no. The entire circuit was intended to use 110 vac, the fact that it worked for 15 minutes with a 220 vac input is a credit to the safety factors built in by the designers.

Next time use a voltage convertor. Many people use them when traveling to Europe. They convert 220 to 110 and allow US equipment to operate on the higher voltage.
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Old 08-17-2011, 07:25 AM
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http://www.overstock.com/Luggage-Bags/Travelon-High-low-Converter-Kit/5036406/product.html?cid=202290&kw={keyword}&adtype=pla
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Old 08-17-2011, 11:10 AM
tom66 tom66 is offline
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Never ever replace a fuse with a higher value unless you know a good reason to do so.

In fact, you should have replaced if anything, you should have replaced with a *lower* value, because at 230V it will draw less current than 115V.

I'm impressed it didn't damage your Xbox because the power supply output would have had higher output ripple and would find it more difficult to regulate the 12V and 5V outputs. If the MOSFETs in the primary side shorted, the Xbox may have seen a large output spike, up to 1/10th the input voltage rectified (for a typical 1:10 SMPS transformer) so around ~32V. Not sure what that would do to the 20V rated MOSFETs and 25V rated electrolytic capacitors in the Xbox. Be careful.

You likely blew up the primary side electrolytics too.
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Last edited by tom66; 08-17-2011 at 11:18 AM.
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Old 08-17-2011, 11:17 AM
tom66 tom66 is offline
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Quote:
Originally Posted by Kermit2 View Post
http://www.overstock.com/Luggage-Bags/Travelon-High-low-Converter-Kit/5036406/product.html?cid=202290&kw={keyword}&adtype=pla
Hmm, I'd be wary of those. I saw one recently that had only a diode in line with the output!! :O The idea was that the diode would halve the waveform and so halve the power and effective voltage. Unfortunately that doesn't actually work, as P = V^2 / R. 230VAC into a 100 ohm load gives 529W; 115VAC into a 100 ohm load gives 132W; halving the time 230VAC is available has double the 115VAC power, so 265W. That's for resistive loads. For things like power supplies, who knows? Probably would blow them up.
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Old 08-17-2011, 12:40 PM
elec_mech elec_mech is offline
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bluemimmosa,
First, varistors, like fuses, are safety devices, you should NEVER remove them unless you're replacing bad ones. They help protect your electronics from surges. Ideally, they blow instead of your expensive electronics.

Second, as everyone has already mentioned, but this still bears repeating, DO NOT replace a fuse with a higher rated one. Like Tom66 said, the power supply is going to draw the same power. If the voltage goes up, the current draw is less.

Third, if this was designed for the U.S., then it is 110V at 60Hz. Not only are you attempting to provide twice the voltage to the supply, you're also changing the frequency. In all likelihood, this is a switching supply and can accept 50Hz, but READ the label on the power supply, it should tell you this. If it is only rated for 60Hz, then a travel adapter going from 220V to 110V won't do you any good.

Fourth, to answer your original question, no, you cannot simply remove a few parts and change the fuse to change the input voltage of the power supply. Check to make sure the power supply will accept 50Hz then go buy a properly rated transformer. A travel adapter will be okay if and only if a) the power supply can accept 50Hz and b) the wattage of the travel adapter is the same or above the wattage of the power supply.

Or find a genuine XBox power supply rated to work on 220V, 50Hz. There is a good chance you've already damaged the existing power supply and/or your XBox, so finding a new, properly rated supply might be your best bet.
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Old 08-17-2011, 12:46 PM
elec_mech elec_mech is offline
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More info here:

http://support.microsoft.com/kb/907635

I'd recommend looking for a local gaming store and see if they offer replacement power supplies for your Xbox. Bring your existing power supply so you can get the right wattage and plug - it appears they make three flavors, see the article above.
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