SMPS repair

Discussion in 'General Electronics Chat' started by giacomob, Nov 17, 2008.

  1. giacomob

    Thread Starter New Member

    Nov 16, 2008
    Hi everybody,
    I recently found in my junk box a forgotten PC power supply that died a few years ago: it is labeled Solarmax model KC-300 ATX. The failed component is a box type, radial leads capacitor (label 1C3 on the PCB), completely destroyed by heath. Thus I was unable to identify it's type and ratings.
    I tried to identify at least it's function, by tracing the wiring of the surrounding components. In the attached file I sketched part of the related circuitry (not sure everything is accurate...)
    Here, I found a very similar schematic for a generic 300W ATX SMPS; in this schematic, capacitor C5 seems to have the same function as mine; it is rated 2.2 micro, 250V.
    Due to it's function, I suppose it should be a high frequency, low loss capacitor, maybe a polypropilene foil or metallized type?
    In order to fix my PSU, I could possibly rest on several resources: 1) If someone has a similar power supply, maybe he can read the type and value of this component (attached is a close up of the PSU board, with the capacitor removed). Or 2) maybe someone has the full schematic of the Solarmax KC-300, with all the component values. Or 3) some expert can suggest the solution, based on his experience...

    Should the capacitor really be a 2.2 micro, 250V foil type, I couldn't find on the net any with dimensions compatible with the available space on the PCB: the pitch between the mounting holes is 20mm and the total clearance is only slightly larger, as can be seen from the picture. So, what?

    Thank you in advance for your help!!!
  2. S_lannan

    Active Member

    Jun 20, 2007
    it's usually a 630v greencap variety if im not mistaken.
  3. jayann

    New Member

    Dec 16, 2008
    Any body can helpwith aschematic diagram of pst-xs300fa of atx smps.