XBOX - blown capacitor

Buddy Smith wrote: : Hi,

: My xbox was damaged due to lightning. It appears that one capacitor was : quite thoroughly fried.

There is probably more damage than just the cap, if your xbox was zapped by lightning. It will probably be more economical to buy a new one.

: There is a picture here:

: (Look for C7G6 in the bottom right corner, next to the nice burn : mark....)

: I want to solder another capacitor on the board in it's place, but I'm : not sure what the value of the old one was, or how critical that value : might be.

: I believe that this part of the board has something to do with power : regulation, because of the large capacitor that is in the area.

: Any suggestions?

: --buddy

The link appears dead to me so I can't look. As someone else said though, if it blew up a capacitor there's almost certainly much more damage.

I already did buy another one ;) I'm just trying to see if I can repair this one for the novelty of it.

Oops, that should be:

--buddy

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.

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?

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 too small to be one of the larger chip capacitors like C7G8. It also looks like that the traces that C7G6 was soldered to have evaporated along with the capacitor. If up is north, I'm not sure what the trace looked like on the south end, but on the north end, it looks like there was a short trace from the capacitor to a via, which is a connection between different layers of the circuit board. But it looks like there's no metal there anymore to solder to. If you're lucky, the metal is there and is just covered in soot. If the metal is all gone, 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.

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.

You might also ask in alt.games.video.xbox to see if anyone there has fixed the same problem. There is a microsoft.public.xbox as well, but I think the EULA lets the Redmond Hit Squad come after you if you suggest opening up an Xbox. Googling for "xbox repair" also gives a few sites that talk about common problems.

Matt Roberds

was

Wow, that vaporized the pads and everything. Can you trace what it was connected to? Pretty much any semiconductor in the circuit will be toast. I have a feeling that xbox is a parts unit now, if any subassemblies even survived.

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

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.

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.

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.

I wish I knew what it did :)

ttyl,

--buddy

Quite nice huh?

The hard drive, DVD-ROM drive, and power supply are all fine. I have a suspicion the power surge came over the ethernet line, since the power supply has no visible damage and is working properly.

--buddy

That's a pretty good assumption, or the A/V cable from the TV.

I forgot to mention that i lost two NICs, a router, and the NIC on my cable modem at the same time :)

--buddy