1.3 Has No Power, Potential Catastriphic Damage?

[infernal_byte]

I purchased a broken no power Xbox (v1.3) at a game store recently, and decided to take a look and see what the issue was. When I got the Xbox, it did not respond to being plugged in or pushing the power button. I've heard that the clock capacitor is an issue with the Xbox, and noticed that there was corrosion by it. It took me a while to take the capacitor off, almost like it was fused to the board. I was able to eventually get it out, but I ended up breaking off the cathode. (I am relatively new to repairing electronics and although I feel confident soldering, my desoldering skills need some work :-P) It seems like the corrosion is much worse than I initially thought. I am aware that the clock capacitor alone does not cause a no power issue, but rather it corroding the traces around it. What should my next steps be for the repair? Should I take a look at the A trace, or write off the console?

Thank you in advance for any help/advice!

Edited January 20 by infernal_byte

[FrostyMaGee]

Could you post a close up picture of the power rails at 6-8 on the underside of your motherboard (underneath where the clock cap was situated)? 7 is probably where the issue may lie but you should look at them carefully to see if there are any broken traces or other instances of trace rot there that need to be repaired. That’s a good place to start with visual inspection given the condition of the clock cap you described. 

[Raidernick]

Kind of hard to see but on the image of the bottom of the board on the bottom right where the black square is, under that, there are several traces that run along the edge of the board. Near the bottom of the black square where those traces make a zig-zag they look corroded, but it's hard to tell with the bad image and flux everywhere. If those traces are bad the xbox will appear completely dead and the power button won't do anything.

[infernal_byte]

I have taken some more photos and uploaded them to this album. It does appear that trace 7 where it zig-zags is corroded. I wasn't able to pry off the black pad covering the trace, but I assume I'll still have to rerun this trace. I've also taken a look at the clock cap location first thing in the morning, and this picture makes it look bad. I hope I can clean all of that corrosion off

[Raidernick]

Yeah at least that one trace is bad. There are test pads from the beginning of the trace to the end of the trace that you can test on to see if there is continuity through the whole thing. As for the clock cap area, you DEFINITELY need to clean than before doing anything else, and make sure you get under the caps around where it was as they all definitely have corrosion under them.

[Marty]

There is some serious damage to a resistor below where the clock capacitor used to be.

What happened?

[Raidernick]

1 hour ago, Marty said:

There is some serious damage to a resistor below where the clock capacitor used to be.

What happened?

That's actually a ceramic capacitor and it looks like it exploded.

[FrostyMaGee]

5 hours ago, Raidernick said:

That's actually a ceramic capacitor and it looks like it exploded.

It really does look like that may have happened. Yikes! That might explain some of the rest right in that area. Along with a leaking clock cap of course. It’s definitely rough looking in that whole part of the mobo. I’d like to see what it looks like after he does a good cleaning to reassess. 

[FrostyMaGee]

I’m just seeing a lot of corrosion spots that are worrisome though. Hopefully it’s not too far gone. 

[infernal_byte]

I have some good news. It looks like all the traces that run through 6-8 appear to be fine! I checked for continuity through all of them and they seemed to be good all the way to the top of the board, including the one in the bottom right corner. I also went and took an old toothbrush with 91% IPA and tried to get at the corrosion. Like @Raidernick said, it does look like something exploded on the board. Some basic Googling told me that the ceramic capacitor (C7G7) was rated "8nf 0603". I'm hoping that it's not required to run the box, as it looks like the trace is basically destroyed.

I also took some more photos, it's nice to be able to see things up close! There is still some corrosion along the backside of Q7G2. I plan on giving this area of the motherboard a good soaking with a baking soda, vinegar, and IPA. R7G3 appears to have come loose from the corrosion. C6G3, C6G1, and C7G6 appear to also be leaking. I planning on replacing these caps. Thank you @FrostyMaGee and @Raidernick for helping me out! I would throw you a beer if I could Hopefully I can get some more insight on anything else I should check before I try to power the box. If there are any other angles I should upload, I can upload them Album here.

[FrostyMaGee]

Just off the top of my head I’d suggest replacing C1E1, C2E4, and C3E2 (the three near the cpu just in case I didn’t recall all the location codes correctly lol) when you’re replacing the others. They are 3300 microfarad 6.3v and are 10mm diameter by 25mm length for that revision board. These can have a direct effect on your power as well (though in this case there are probably multiple things). They look ok from your pictures but at this point are really old anyway and should be replaced. Since you’ll be replacing some other radial caps already I thought I mention them. 

[infernal_byte]

So I was able to give the board a good cleaning and replaced the capacitors that were leaking around the clock cap. I haven't replaced any of the other capacitors yet, but I plan on it once I can get it to at least power on for a bit. The board seems to be looking much better now, I am just waiting on some UV solder mast to come in so I can cover the exposed copper.

I tried to power on the system, but it still isn't showing any signs of life. I checked for shorts on the PSU (Foxlink) connector on the motherboard, and I saw some low resistance on the pins. Blue circle shows low resistance.

I'm not sure if I checked the proper way, so I have a video of me going through all of the PSU pins here. New board pics here, these are before I put on C7G1 and C7G6.

I also checked on the P/E Traces and it seems those are solid. I'm a bit stumped as to where the short could be. I imagine that the area where the resistor blew up is where the short is, but I'm not sure how I could fix that properly. I got a grinding pen and was able to remove most of the carbon that was around that area. The area around Q7G2 seems like it has a rusted solder joint? R7G3 is also loosely attached, but I'm not sure if it's needed to power this revision of Xbox. I'm currently waiting on a replacement to get in. What do you guys think the short is being caused by? Is it normal for these pins to have low resistance?

Edited February 8 by infernal_byte

[arfows]

Are you seeing any voltage output from the power supply when its plugged in?  specifically are you getting 3.3vdc from purple?  Doesn't need to be connected to xbox when you take the reading for standby voltage

[infernal_byte]

Apologies for the necro, but I was able to get the Xbox working again! I checked the standby voltage as recommended by @arfows and found that there was no output on that line. I also noticed that the power supply was heating up quite a bit. I ended up getting a Delta psu as a replacement and it solved the issue. Got it all TSOPed and it's working flawlessly after some basic testing. Just need to take it online with Halo 2 for it's final exam Thank you all for your help!

[jjjwelch]

I just came across this thread and was going to tell you to check the psu. I have gained many boxes from bad psu's. For future reference, always check the joints on the power inlet on the psu, the joints have a tendency to crack and become an open circuit\poor contact.