armyofmeisbliss Posted August 9, 2023 Report Share Posted August 9, 2023 Hi guys, first time posting here. So, I live in Brazil and the OG Xbox never got sold here. Recently bought one with a defective 110V PSU to attempt to repair and have currently reached a dead end trying to solve it. What I currently have is the following: ===PSU's PRIMARY SIDE=== - First filter cap (the really big one near) has a reading of approx. 170V. - When powering off, the voltage drains off filter cap normally. ===SECONDARY SIDE=== - No bulging caps, haven't recapped. Shorted VSTB to POW-ON to test and got the following: - 3.27V on VSTB to POW-ON, which I understand is what is needed. - 3.16V on VSTB to VS, which I think is low. - 5.3 on DNA1002D's pin 1, which I'm not sure is supposed to be that high. - 13.5V on the HV end of the optocouplers and little to nothing on the other end, which I think is wrong. - nothing on the pins for 5V nor 12V when shorting VSTB to POW-ON My best bet is the voltage is off on the secondary part of the PSU, maybe because of a faulty transistor or resistor (haven't found the fault) and POW-OK isn't triggering the feedback circuit, but I'm not entirely sure. I'm an amateur at best and know I shouldn't be attempting to repair a PSU with little knowledge, but am taking every precaution possible. Any help is much appreciated. Thanks! Quote Link to comment Share on other sites More sharing options...
armyofmeisbliss Posted August 9, 2023 Author Report Share Posted August 9, 2023 Apparently almost everything on the secondary (3VS on orange, 12v on yellow and 5V on red) seems to be shorted to ground, but I can't find the culprit. Removed the 3 transistors and checked, still shorted. Changed the 1002 IC, still shorted. Quote Link to comment Share on other sites More sharing options...
armyofmeisbliss Posted August 12, 2023 Author Report Share Posted August 12, 2023 On 8/9/2023 at 5:34 PM, armyofmeisbliss said: Apparently almost everything on the secondary (3VS on orange, 12v on yellow and 5V on red) seems to be shorted to ground, but I can't find the culprit. Removed the 3 transistors and checked, still shorted. Changed the 1002 IC, still shorted. nvmd, got a new multimeter, old one was apparently fried. New readings point to a faulty zener diode, but it has no markings as to show what voltage it pertains to. pic below Quote Link to comment Share on other sites More sharing options...
SS_Dave Posted August 12, 2023 Report Share Posted August 12, 2023 That will be a small signal switch diode line a 1n914 A Zener would be marked something like ZD904 What make and model supply is it? Cheers SS Dave Soft modding is like masturbating, It gets the job done but it's nothing like the real thing. 1 Quote Link to comment Share on other sites More sharing options...
armyofmeisbliss Posted August 12, 2023 Author Report Share Posted August 12, 2023 18 hours ago, SS_Dave said: That will be a small signal switch diode line a 1n914 A Zener would be marked something like ZD904 What make and model supply is it? Cheers SS Dave Soft modding is like masturbating, It gets the job done but it's nothing like the real thing. Thanks! It's a Delta Electronics 100-127V PSU (DPSN-96BP). From the xbox repair guide I gathered it's a version 1.4 Delta PSU. Quote Link to comment Share on other sites More sharing options...
armyofmeisbliss Posted August 14, 2023 Author Report Share Posted August 14, 2023 On 8/12/2023 at 2:09 AM, SS_Dave said: That will be a small signal switch diode line a 1n914 A Zener would be marked something like ZD904 What make and model supply is it? Cheers SS Dave Soft modding is like masturbating, It gets the job done but it's nothing like the real thing. I can't seem to find a proper schematic for this PSU, would you happen to have it? It'd help a lot! Thanks. Quote Link to comment Share on other sites More sharing options...
SS_Dave Posted August 16, 2023 Report Share Posted August 16, 2023 On 8/15/2023 at 3:57 AM, armyofmeisbliss said: I can't seem to find a proper schematic for this PSU, would you happen to have it? It'd help a lot! Thanks. As far as I know the M$ Original Xbox there has never been any leaked circuits. The only way would be compare a working PSU against the one you have 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...
armyofmeisbliss Posted August 25, 2023 Author Report Share Posted August 25, 2023 On 8/16/2023 at 6:20 AM, SS_Dave said: As far as I know the M$ Original Xbox there has never been any leaked circuits. The only way would be compare a working PSU against the one you have Cheers SS Dave Soft modding is like masturbating, It gets the job done but it's nothing like the real thing. Thanks, I got a new and functioning PSU and figured out that signal diode was fried. Have no idea which one to buy, so I'll be using the new PSU instead *shrug* Cheers Quote Link to comment Share on other sites More sharing options...
Bowlsnapper Posted August 25, 2023 Report Share Posted August 25, 2023 21 minutes ago, armyofmeisbliss said: Thanks, I got a new and functioning PSU and figured out that signal diode was fried. Have no idea which one to buy, so I'll be using the new PSU instead *shrug* Cheers How did you determine that? Quote Link to comment Share on other sites More sharing options...
armyofmeisbliss Posted August 25, 2023 Author Report Share Posted August 25, 2023 11 hours ago, Bowlsnapper said: How did you determine that? You mean that the diode was fried? Readings differed on the damaged and functioning one. On the damaged it was open circuit. Quote Link to comment Share on other sites More sharing options...
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