tssfka Posted July 27, 2022 Report Share Posted July 27, 2022 Hi everyone, new to the forum but looks like it's the right place for me to visit. I have an Xbox 1.6b (2005, Australian 240V model). Tonight it wouldn't fire up at all, completely dead and unresponsive to the power button. I opened it up and there was no obvious damage on the mobo. All i could measure on the 20 pin molex from the psu were some very low voltage (0.6V) on the 5V pins. 12V was reading 0. Ac input fuses showed good continuity. The only thing that looks suspect on the psu is the component in R10. I measured across the pins for R10 and its reading open circuit. I reflowed the solder on the AC input pins, no change. The xbox has been moldded since purchase but has been working perfectly until tonight. Nothing has been changed in the last 15 years. Still in original case. The original power cable seems to be intermittent now but other cables tried and no change. Any suggestions to help diagnose would be appreciated as I couldn't t find any replacement psu online anymore. OG psu is Tuscany rev 1.0. Tyia, tssfka Quote Link to comment Share on other sites More sharing options...
tssfka Posted July 27, 2022 Author Report Share Posted July 27, 2022 Photo of internals Quote Link to comment Share on other sites More sharing options...
Prehistoricman Posted July 27, 2022 Report Share Posted July 27, 2022 Can you unplug the Xbox from the mains, disconnect the motherboard power connector, wait at least a minute, then plug it back in and measure the voltage between any red and black wires on the connector? That R10 resistor should probably not read open circuit. It may be a fusible type and broken open. You can remove the heatshink carefully to see if it looks damaged. Quote Link to comment Share on other sites More sharing options...
tssfka Posted July 27, 2022 Author Report Share Posted July 27, 2022 5 hours ago, Prehistoricman said: ... measure the voltage between any red and black wires on the connector? The voltage black to red was 0.3V initially but quickly dropped to 0.03V and stayed there while reading. Quote Link to comment Share on other sites More sharing options...
Prehistoricman Posted July 27, 2022 Report Share Posted July 27, 2022 2 minutes ago, tssfka said: The voltage black to red was 0.3V initially but quickly dropped to 0.03V and stayed there while reading. Can you start making the measurement before plugging in the Xbox, then plug it in and see if it goes to a higher voltage? Quote Link to comment Share on other sites More sharing options...
tssfka Posted July 28, 2022 Author Report Share Posted July 28, 2022 20 pin unplugged, power unplugged, connect to power, hits 0.45V peak on red pin and stays there for a while before dropping slowly. Quote Link to comment Share on other sites More sharing options...
Prehistoricman Posted July 28, 2022 Report Share Posted July 28, 2022 Yeah that doesn't sound good. You can try desoldering the suspect resistor and unwrap it to see its value. See if you can find a replacement and maybe that will fix it. While you have the PSU out, check the resistance between pins on the heatsinked devices. They are usually 3-pin transistors and these often fail short-circuit. Also measure the resistance of the fuse which is the brown cylinder next to the AC in plug. Quote Link to comment Share on other sites More sharing options...
tssfka Posted July 29, 2022 Author Report Share Posted July 29, 2022 Thanks will do. I really appreciate the help. Also, I have the opportunity to buy a "for parts" xbox but the psu looks like it is from a 1.5 version. Is it possible to reassign the pins and use a psu cross models? I haven't seen a post about that being effective. Alternatively I'm looking at an atx psu mod. Quote Link to comment Share on other sites More sharing options...
SS_Dave Posted July 29, 2022 Report Share Posted July 29, 2022 3 hours ago, tssfka said: Thanks will do. I really appreciate the help. Also, I have the opportunity to buy a "for parts" xbox but the psu looks like it is from a 1.5 version. Is it possible to reassign the pins and use a psu cross models? I haven't seen a post about that being effective. Alternatively I'm looking at an atx psu mod. There is no 1.5 version The 1.2-1.4 have the same power supply and the 1.6 has the same 20 pin plug as the 1.2-1.4 but in not compatible. Cheers SS Dave Soft modding is like masturbating, It gets the job done but it's nothing like the real thing. Quote Link to comment Share on other sites More sharing options...
tssfka Posted July 29, 2022 Author Report Share Posted July 29, 2022 Further to this last message I did some more checking. Brown fuse is OK. R10 resistor is OK (i had wrong scale set on meter, it's 66kOhm). I rigged up a temporary power patch using an atx psu and there's some life left in it. It will turn over the fans but I couldn't give it enough power to get it to boot up with the av cable connected. I did find a discrepancy with the tuscany markings and the pin out diagrams for the v1.6b. The 5v and 5vsb appear swapped in the pin outs I've seen. Definitely looks psu related so I hope it can be resurrected. This xbox is older than my children (my wife says the xbox is not our child though). Quote Link to comment Share on other sites More sharing options...
tssfka Posted July 29, 2022 Author Report Share Posted July 29, 2022 14 minutes ago, SS_Dave said: There is no 1.5 version My bad. Should have said "not 1.6". The donor I was looking at is 2004 build. Oh well, will explore other options... Quote Link to comment Share on other sites More sharing options...
KaosEngineer Posted July 29, 2022 Report Share Posted July 29, 2022 On 7/27/2022 at 6:54 PM, tssfka said: The voltage black to red was 0.3V initially but quickly dropped to 0.03V and stayed there while reading. Take the guts of the console out of the case. Does it now have the standby 5 Vdc voltage present? Be careful to place the PSU on a non-conductive surface and do not touch it when AC power is connected. You will most likely get a shocking surprise. If the case is not for a v1.6 motherboard, it may be shorting out the PSU which turns off by the PSUs over-current protection. Edit: Please post a picture of the bottom of the case showing all of the motherboard mounting posts. Quote Link to comment Share on other sites More sharing options...
tssfka Posted July 30, 2022 Author Report Share Posted July 30, 2022 The case is original for the console and the measurements were with the psu removed completely Quote Link to comment Share on other sites More sharing options...
tssfka Posted August 8, 2022 Author Report Share Posted August 8, 2022 Update on the status is that I'm back up and running with a replacement power supply. Thanks to all for the helpful replies to troubleshoot. Quote Link to comment Share on other sites More sharing options...
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