I did something stupid -- PSU voltage set wrong

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • cyclones
    Senior Member
    • Feb 2010
    • 69

    #1

    I did something stupid -- PSU voltage set wrong

    I was asked to check out a computer yesterday that wasn't working. It is used with some older scientific equipment, that was just given to us. The computer itself is a generic Pentium 4 PC that has ISA slots for a machine control card. The computer was NOT starting up, and after reseating the memory and checking connections, I couldn't find anything wrong.

    It was plugged in to what appeared to be a line conditioner, as were several other things. The plug was normal PSU plug on one end, and on the other it wasn't an outlet plug, but was one of these types: http://www.cableclub.com/images/20573.jpg

    The "line conditioner" had labeled power plugs for the computer, an IBM LCD monitor, printer, and the scientific equipment. The weird thing was that the computer was set for 230v operation (I'm sure you can see where this is going). I looked the line conditioner thing over, and the only thing I found was a small label on the front that said "110v". There was a booklet on the equipment which i looked through and found no specifications on the line conditioner type box. The box was plugged into a regular 120v outlet. After looking everything over, I thought the computer must set to the wrong voltage. Like an idiot, I didn't go and track down a volt-ohm meter. I switched it on to the sound gunfire -- or what sounded like it -- as caps blew in the PSU. I pulled the plug right away -- just as a small amount of smoke came out of the PSU. I cussed so loud they heard it in Minnesota. I've been beating myself over the head for the last 24 hours.

    So apparently this black (actually ivory color) box is a step-up transformer. Wonderful. I know the power supply is gone, but what are the chances of reviving the motherboard? i would just throw a different one in, but it has ISA slots, AND that proprietary card. If anything, I need to try to salvage that card. I can probably buy another board from the MB manufacturer, who I have located, although ISA P4 boards look to be around $300. There is no VISIBLE damage to the motherboard, but I expect something got damaged.

    Would one of the experts PLEEEEASE help me try to figure out how bad the damage is and if this is salvageable? Where should I start?


    Thanks!!!!!
  • PlainBill
    Badcaps Legend
    • Feb 2009
    • 7034
    • USA

    #2
    Re: I did something stupid -- PSU voltage set wrong

    Originally posted by cyclones
    I was asked to check out a computer yesterday that wasn't working. It is used with some older scientific equipment, that was just given to us. The computer itself is a generic Pentium 4 PC that has ISA slots for a machine control card. The computer was NOT starting up, and after reseating the memory and checking connections, I couldn't find anything wrong.

    It was plugged in to what appeared to be a line conditioner, as were several other things. The plug was normal PSU plug on one end, and on the other it wasn't an outlet plug, but was one of these types: http://www.cableclub.com/images/20573.jpg

    The "line conditioner" had labeled power plugs for the computer, an IBM LCD monitor, printer, and the scientific equipment. The weird thing was that the computer was set for 230v operation (I'm sure you can see where this is going). I looked the line conditioner thing over, and the only thing I found was a small label on the front that said "110v". There was a booklet on the equipment which i looked through and found no specifications on the line conditioner type box. The box was plugged into a regular 120v outlet. After looking everything over, I thought the computer must set to the wrong voltage. Like an idiot, I didn't go and track down a volt-ohm meter. I switched it on to the sound gunfire -- or what sounded like it -- as caps blew in the PSU. I pulled the plug right away -- just as a small amount of smoke came out of the PSU. I cussed so loud they heard it in Minnesota. I've been beating myself over the head for the last 24 hours.

    So apparently this black (actually ivory color) box is a step-up transformer. Wonderful. I know the power supply is gone, but what are the chances of reviving the motherboard? i would just throw a different one in, but it has ISA slots, AND that proprietary card. If anything, I need to try to salvage that card. I can probably buy another board from the MB manufacturer, who I have located, although ISA P4 boards look to be around $300. There is no VISIBLE damage to the motherboard, but I expect something got damaged.

    Would one of the experts PLEEEEASE help me try to figure out how bad the damage is and if this is salvageable? Where should I start?


    Thanks!!!!!
    Have you tried replacing the power supply? At a first guess, very little of the voltage surege should have been passed through to the motherboard.

    If it is an odd-ball power supply, there is a subforum here that deals with repairing power supplies.

    PlainBill
    For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.

    Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.

    Comment

    • cyclones
      Senior Member
      • Feb 2010
      • 69

      #3
      Re: I did something stupid -- PSU voltage set wrong

      I had actually tried using a power supply that was sitting around. It didn't work. It turns out that the power supply was bad and a known-good power supply brought the computer up. So good, I think it's all working. Thanks for your suggestion.

      Comment

      Related Topics

      Collapse

      • sam_sam_sam
        Trip light 2400 watt line conditioner bought used issue with low voltage oscillation going on between relays
        by sam_sam_sam
        I found two capacitors on the board and one of the leads on one capacitor had bad soldering joint and the other joint connections not much better and there were several soldering joints that way to much flux around the joint redid several of them

        The capacitors were a non brand that I did not recognize they got replaced and now it does not oscillating between relay but what concerns me a little bit is when the voltage is a little bit low the output voltage is around 130 volts and then drops down to 115 volts this happens around 105 to 108 volts if remember correctly

        Now...
        06-09-2024, 10:57 AM
      • sam_sam_sam
        110 Volt Line Conditioner ( 12 volt regulator cap failure repair once before)
        by sam_sam_sam
        About 5 years ( or ) more ago I had recap this line conditioner because it would rapidly relay clicking so that was the reason for having to recap the board

        The other thing it was doing every time the air conditioner would turn ON it would click this started about 2 weeks ago

        We have a lot of voltage dipping where I live ( 110 to 126 volts ac ) so I was not surprised that it was doing this but I have two more of units that were not doing this all time but i I did not give it much thought but maybe I should have but it is a pain in the butt to work on this unit
        ...
        06-20-2020, 05:01 PM
      • cubytus
        Samsung UN50TU8000FXZC shows thin horizontal green line when warm
        by cubytus
        Hi to all,

        I was given this TV, an entry-level 4K 50" set. Some have criticized its lack of contrast and relatively poor colour rendering, but for my needs, it's very decent.

        I reset everything to factory settings, but this line keeps on fading in and out when watching a streaming channel from the Tizen firmware. Interestingly, it only happens when TV is warm, after about 1h45 of it being turned on.

        Watching a movie from an external source doesn't trigger the line as easily (needs 2 hours), and from a normal viewing distance, is hardly noticeable. It...
        01-10-2024, 01:26 AM
      • TrueSword88
        Kogan - KALED65XU9220STB - Blue Vertical Line
        by TrueSword88
        Hi all.

        I have a Kogan 65' LCD Panel with a thin blue vertical line (top to bottom) on left hand side of panel.
        The line just happens to coincide with the end of COF and start of the next COF (attached).

        The line is permanent no matter what I've tried. I've tried pressure testing the panel (top to bottom) and all over, I didn't notice any difference with the line, either temporary or semi-permanent.

        Also tried unplugging all flex cables, cleaned with isopropyl then re-inserting to no avail - line remains.


        Hoping to fix...
        05-05-2023, 04:28 PM
      • mindoverflow
        ASUS GTX 1650 Gpu.Initialize Interrupt request line stuck asserted
        by mindoverflow
        hello,

        there is an asus gtx1650 which displays fine in windows but if i run a benchmark test it displays artifacts and the driver crashes after a second or two.

        I changed pads and thermal paste.

        I run mats test but it is reporting 0 errors.

        I then tried to run the mods version 400.271_1650 test, it first ran and stopped with a 'breakpoints limit reached after 5 retries' error and the fans went full speed.

        After a reboot, I tried to run the test again, but now the test fails and says "ERROR: Couldn't clear GPU's interrupt...
        02-09-2022, 03:22 PM
      • Loading...
      • No more items.
      Working...