DIYbanter - View Single Post - XBOX

wrote:

Does it use an external power supply? If so I'd check that first to see
if it's putting out the correct voltages. If it has an internal power
supply, check the fuse that should be located somewhere near the line
cord input.

It does use a separate power supply. I have confirmed that the power
supply is working properly (it even works in another xbox).

If the power supply seems OK, can you get the new Xbox apart? (You'll
void your warranty.) You might be able to determine the value of the
fried cap by looking at the same place in the new one. You can also make
voltage measurements at the same places in the new and broken ones to
see if there are other problems. Does the broken one even try to start
up (hard drive tries to spin up, power light blinks) or is it totally
dead?

It tries to boot up. I can see at least one fan stuttering, but it does
not boot successfully. It either won't come on at all or will come on
for less than one second before turning off and trying again.

I agree that this part of the board looks like something to do with
power regulation. C7G6 looks like it _was_ a small ceramic? chip
capacitor, the same physical size as C7G7. The spot on the board looks

This is indeed the type of capacitor that it was. I don't have the
other xbox apart enough at the moment to find out if it's the same size
as the larger or smaller of the chip capacitors.

you might still luck out if this via went all the way through the board -
you'd have to take the board out and turn it over to know for sure. For
comparison, there is an undamaged via just north of the burn mark and
just south of the C7G10 label.

There are two vias on either side of where the cap used to be that are
connected to it, so I do have a point I can connect to to replace the
cap.

Another question is: what did this capacitor do? If it was just being
used to filter out high-frequency noise from a supply rail (which is
somewhat likely in a power supply), and nothing else is damaged, the
box may work reasonably well without it. But if it was in the control
circuit of a switching regulator, the box may not even start up without
it.

I wish I knew what it did

ttyl,

--buddy