BillFences Posted August 9, 2022 Report Share Posted August 9, 2022 (edited) Hi, I'm trying to repair my xbox v1.6 with a Delta 220v PSU because it doesn't power on at all(even the fan isn't spinning). Backstory: the xbox stopped working all of a sudden(it worked just the day before even with the leaked/bulging caps), so thinking that maybe the power and eject buttons got broken, I tried to turn it on by shorting the SW1 Eject or SW2 Power(I can't remember which) to GND according to this diagram of the front panel connector. I don't think this was a good idea since the xbox didn't turn on and I heard a small spark but I'm not totally sure. Now from the PSU, not plugged into the motherboard(so in stand-by I guess), I get a ~5v reading from the orange wires but 0.1v from the blue wire(which should be 3.3v even on stand-by according to this table) and ~0 volts from the other 3.3v and 12v rail as it should be. Moving on to the motherboard, after removing all the bad capacitors, I still get a short between the 5v rail and ground(measuring the pins of psu connector on the motherboard). I also tried measuring the caps under the CPU(starting from C2P1 to C2P17) and they're all shorted to ground. The caps C2E2 and C1E1 too. Also, measuring the VRM(?) FAN5059M I'm getting a short on the pins(apart from GND) 2_SW, 6_VID2, 8_VID0, 20_VFP. All this leds me to believe that the CPU is fried but I can't really wrap my head around how I could have done that, is there something I'm missing/misunderstanding? Image 1 mobo Image 2 mobo Image 3 cpu caps Edited August 9, 2022 by BillFences Added specification Quote Link to comment Share on other sites More sharing options...
Prehistoricman Posted August 9, 2022 Report Share Posted August 9, 2022 What resistance do you read as "shorted to ground"? If it's just the continuity beep, then you can't trust this because it has some arbitrary threshold. Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 9, 2022 Author Report Share Posted August 9, 2022 10 minutes ago, Prehistoricman said: What resistance do you read as "shorted to ground"? If it's just the continuity beep, then you can't trust this because it has some arbitrary threshold. Oh yeah, you're right I completely forgot about that. In resistance mode it's less than 1 ohm(it oscillates between 0.1 and 0.2 ohms) for the caps under the CPU, C1E2, C2E2 and C1E1. For the caps C1G10 and C1F2 is 153 ohms. Quote Link to comment Share on other sites More sharing options...
Prehistoricman Posted August 9, 2022 Report Share Posted August 9, 2022 I get about 30 ohms for C1E2 and the caps under the CPU. 155 ohms for C1G10. This sounds bad for your CPU but the issue could still be some other component involved with that power rail such as the switching regulator controller or the switching transistors. Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 9, 2022 Author Report Share Posted August 9, 2022 (edited) 28 minutes ago, Prehistoricman said: other component involved with that power rail such as the switching regulator controller or the switching transistors Could you tell me their codes on the PCB? And how I can figure if they're broken? Edited August 9, 2022 by BillFences Quote Link to comment Share on other sites More sharing options...
Prehistoricman Posted August 9, 2022 Report Share Posted August 9, 2022 In your first post, you said that the blue wire was 0.1V. This is normal because the signal comes from the motherboard. Plug in the power connector and re-check this signal. You also measured continuity around the FAN5059M chip. The readings for pins 2 and 20 are abnormal, but they are to be expected when you measure the other shorts to ground. Essentially you are measuring the same wires. 50 minutes ago, BillFences said: Could you tell me their codes on the PCB? And how I can figure if they're broken? U2T1 (the FAN5059M chip) which you could desolder and re-measure the resistances. I don't know about the transistors. You could try desoldering the switching inductor L2F1. Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 9, 2022 Author Report Share Posted August 9, 2022 26 minutes ago, Prehistoricman said: In your first post, you said that the blue wire was 0.1V. This is normal because the signal comes from the motherboard. Plug in the power connector and re-check this signal. You also measured continuity around the FAN5059M chip. The readings for pins 2 and 20 are abnormal, but they are to be expected when you measure the other shorts to ground. Essentially you are measuring the same wires. U2T1 (the FAN5059M chip) which you could desolder and re-measure the resistances. I don't know about the transistors. You could try desoldering the switching inductor L2F1. I desoldered the chip and the resistance for C1G10 increased to 161ohms but the caps under the cpu initially show a high value but then quickly stabilize to basically zero as before... if there's nothing else left I might try desoldering the cpu and seeing if the issue is fixed just for the sake of it. Quote Link to comment Share on other sites More sharing options...
KaosEngineer Posted August 9, 2022 Report Share Posted August 9, 2022 Simply replace the 5 3300 μF 6.3Vdc ultra-low ESR 105° C rated caps by the CPU and PSU connector. EEU-FS0J332B Panasonic Electronic Components | Capacitors | DigiKey Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 9, 2022 Author Report Share Posted August 9, 2022 4 hours ago, Prehistoricman said: In your first post, you said that the blue wire was 0.1V. This is normal because the signal comes from the motherboard. Plug in the power connector and re-check this signal. I plugged it in and I read 3.3v. I also read 3.3v on the transistor near the Xyclops chip. Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 9, 2022 Author Report Share Posted August 9, 2022 (edited) 1 hour ago, KaosEngineer said: Simply replace the 5 3300 μF 6.3Vdc ultra-low ESR 105° C rated caps by the CPU and PSU connector. EEU-FS0J332B Panasonic Electronic Components | Capacitors | DigiKey I don't have them at hand, can they be replaced with some lower value caps(1000uF or 2000uF) just to see if it at least turns on? Edit Also I could try reflowing the mcpx chip as seen in this topic maybe? Edited August 9, 2022 by BillFences Quote Link to comment Share on other sites More sharing options...
KaosEngineer Posted August 9, 2022 Report Share Posted August 9, 2022 Don't do anything drastic until after replacing the 5 3300 microFarad caps. I don't know how low is too low for these capacitors. They also need to have a low-ESR (Equivalent Series Resistance) value, not your average electrolytic capacitor. Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 9, 2022 Author Report Share Posted August 9, 2022 These capacitors have a bit higher ESR(32 mOhms instead of 20) and lower lifetime, but I think they're good enough since they cost 1/3 of the panasonic ones, what do you think? Also are there any other capacitors that would be better to replace?(in addition to the clock cap) Quote Link to comment Share on other sites More sharing options...
KaosEngineer Posted August 10, 2022 Report Share Posted August 10, 2022 6 hours ago, BillFences said: These capacitors have a bit higher ESR(32 mOhms instead of 20) and lower lifetime, but I think they're good enough since they cost 1/3 of the panasonic ones, what do you think? Also are there any other capacitors that would be better to replace?(in addition to the clock cap) I believe they will be okay. The Panasonic's have a 10,000 hour endurance vs. these Rubycon's at 3000 hours. I do see that they are 2.5mm larger in diameter. Rubycon size: 12.5mm dia x 20mm H vs. Panasonic: 10mm dia x 20mm H. Is there enough space for them to fit? Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 10, 2022 Author Report Share Posted August 10, 2022 7 hours ago, KaosEngineer said: I do see that they are 2.5mm larger in diameter. Rubycon size: 12.5mm dia x 20mm H vs. Panasonic: 10mm dia x 20mm H. Is there enough space for them to fit? They barely fit, I'm gonna go with the ones you linked. Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 12, 2022 Author Report Share Posted August 12, 2022 (edited) On 8/9/2022 at 11:55 PM, KaosEngineer said: Don't do anything drastic until after replacing the 5 3300 microFarad caps. Ok, I replaced the 5 caps and now it's booting up but it's giving an error: https://imgur.com/a/a25MZ1I It does the same thing with the drive, hdd(which I can hear spin) and AV plugged in. Also I don't see any solder splashes on the motherboard, although I accidentally desoldered an smd capacitor but I didn't know for sure where it came from, so I soldered it next to the VRM chip https://imgur.com/a/Dx1S5R2 Edited August 12, 2022 by BillFences Quote Link to comment Share on other sites More sharing options...
BillFences Posted August 13, 2022 Author Report Share Posted August 13, 2022 @KaosEngineerAfter reflowing the caps in case the solder didn't make it all the way through the holes, the xbox was back to not powering on at all: dead short on the cpu caps and the power supply even seemed to enter a kind of overcurrent protection because I couldn't measure any voltage on the motherboard. So, pretty bummed out, I decided to reflow the mcpx chip but to no avail. I moved on to desoldering the cpu and finally there are no shorts! The measurements I got after removing the cpu(everything else soldered on): ~70ohms for C1E2 and the smd caps under the cpu, ~67ohms for C1G10 and 60 ohms for all the other cpu caps. 5 volts on all the cpu caps and the caps under the cpu and also 3.3 volts for the transistor near the Xyclops chip. So it seems like the cpu was really fried. If I can get another cpu, will I just need to solder it back on? Also, do you know what other component I should check? I find it hard to believe that there's nothing else broken if the cpu died. Quote Link to comment Share on other sites More sharing options...
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