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    Cheap Capacitors fail under load

    Posted on Saturday, January 22nd, 2011

    Customer brought in a Desktop computer that would not power on.  The Tower was made by gateway and it had a upgraded video card inside it (pci express card.)  The system was running 2 hard drives, DVD -rw, card reader, 2 fans,  the motherboard and a pny nvidia card (required a 350 watt power supply.)

    The cheaply manufactured Bestec power supply (oem in this system) was labeled a 300 watt, when the bestec label clearly states in small writing 285 watt.

    However even a good quality 300 watt would be able to handle a card requiring 350 watt if its not fully loaded with devices (if all ports are not used.)  This unit failed in 2 spots at the same time.

    As seen in the pictures below the caps removed that were failed were cheaper 10volt 2200 uf  and a 16volt 2200 uf, in the second picture compare to a better made 10volt 2200 uf and 16volt 2200 uf, you can see the size difference in the better part.

    Bad Caps needing replacement

    Bad Caps needing replacement

    Bad Caps next to Replacements

    Bad Caps next to Replacements

    The cheaper parts labeled OST were replaced with fresh Rubycon and Jackcon caps and Power supply is alive again.

    The power supply was not returned to the system it was replaced with a 400 watt to avoid any further problems.

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    Cheaply Made Power Supply Failure

    Posted on Friday, July 23rd, 2010

    I received a custom tower the other day for a no boot diagnostic test.   The customer noted that, it won’t boot and it makes a noise if you try to turn it on.  Testing confirmed the power supply was the cause, a replacement was acquired and installed.

    The problem was solved, but you why did the component fail?

    Opening the Star Power (off brand) power supply, that was rated 480watt, I found something unusual.

    starpower cheap off brand power supply

    starpower cheap off brand power supply

    The sinks on the 12volt and 5 volt sides were extremely small for its rating.  I looked in to it and it’s not because of efficiency, just small heat sinks, that’s why there was 2 fans running inside this unit just to keep it cool.   The cause of the failure was found to be an ejected capacitor; yes it was ejected, not blown.

    starpower cap failure

    starpower cap failure

    The supply was so cheaply manufactured that the china made capacitor did not vent it just exploded off its membrane.  They were lucky this did not start an electric fire when this happened.

    This unit was crushed for recycling to prevent anyone from attempting a fix

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    Inspiron Fan Bearing Failure

    Posted on Tuesday, July 20th, 2010

    I received an inspiron 9300 from a client of mine the other day for a backup and re-install of there OS.  The complaint was that it was shutting down, giving blue screens, and they requested the format and re-install.

    The moment I turned it on I could hear the cause of the problems.  As soon as the fan powered on there was a scraping and squealing from the fan. The fan was just not running more than a few turns.

    I inspected the fan, heat sinks and exhaust ports for obstructions, but found the fan was no long level with its casing.  IT had experienced a bearing failure, making it generate noise and scrape the sides of the casing.  This was the cause of the shut down issues, due to overheating.  A new fan was acquired for the system, however with multiple shutdowns there could be file system damages, so the OS was reloaded as well.

    Problem solved.

    Inspiron 9300 fan bearing issue

    Inspiron 9300 fan bearing issue

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