Power supply not responding after install

By geno368
Aug 22, 2009
  1. I am working on a pc running XP pro that has a bad PS. I took one out of another working pc with same voltage values and installed it. When I plug it in and turn it on, I get not response whatever. I put a multimeter on some of the molex connectors, and no power. The mother board looks ok(no bulges on Capacitors), but the system may have other problems since it has been down several months and I don't know any history. What should I look at next? Thanks in advance.
  2. captaincranky

    captaincranky TechSpot Addict Posts: 11,467   +1,760

    I would think that you might at least have 12 volts at the fan plugs. No?

    Does the PSU still show the correct voltages with it disconnected from the board. If no, then the board ruined the supply.
  3. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,233   +234

    Do you have the case power switch properly connected to the motherboard? You can momentarily short the motherboard power switch pins and see if the power supply starts. +3 volts momentarily shorted to ground, starts the supply
  4. geno368

    geno368 TS Rookie Topic Starter

    It seems after checking PS again that the MB fried it...Thanks for the help
  5. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,233   +234

    So you will replace the motherboard?
  6. geno368

    geno368 TS Rookie Topic Starter

    I guess so, and another PS. I can't find a brand or part number on the board and this is a local computer co. build that is no longer in business. Don't have a clue what to order...
  7. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,233   +234

    There should be a number on a paper lable near the back USB ports or stamped between two PCI sockets or near the memory sockets and the CPU
  8. dmill89

    dmill89 TS Guru Posts: 475

    Also If it was done by a local shop they probably gave you a manual or driver CDs with the manufacture and model number of the board. As Tmagic650 said it should also be on the board someware (either on a paper label or silkscreened into the board itself). Unfortunately cheap powersupplies are verry common in systems built by local shops. Most just use whatever comes with the case or if the case does not include a PSU they usually use cheapest thing that will run the system unless you specify otherwise and pay the aditional cost of an upgraded unit. Low quality motherboards that are failure prone are also commonly used by shops (slightly less common than cheap PSUs) unless the customer specifies a specific manufacture or model they also oftain use the cheapest board that supports the selected components(cpu,ram,video,drives,etc.).
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