How to check an LNB for faults?

Discussion in 'Satellite TV' started by Geerdub, Feb 13, 2011.

  1. Geerdub

    Geerdub Member

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    Hi,

    I have had two humax boxes die in a row. Before I plug the third one into the system I want to be 100% sure that I am just very unlucky and confirm that there is nothing wrong with the set up or lnb.

    What is the best way of testing an lnb? Have tested for shorts at the sockets and get about 5Mohm. sound ok? What else can I check?

    Cheers
     
  2. pedro2000uk

    pedro2000uk Installer/Design Engineer

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    also check any of your media gear it's connected to for stray voltage faults etc..
     
  3. Geerdub

    Geerdub Member

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    Cheers Pedro,

    The only other connection apart form the LNB is the HDMI cable to the 6 Series 6 Samsung LEDtv.

    I did notice when the second humax died that the back of the box felt tingly to the touch :shocked: and this went away when I pulled the HDMI....

    Does that make sense that there could be stray voltage from the TV killing the Humax?

    Fualty TV- Faulty HDMI cable? Whats best way to check? Get a pinout for an HDMI cable and check voltages?

    Many thanks
     
  4. Geerdub

    Geerdub Member

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    Right, further investigation shows 45vac on standby and 60vac potential between tv case (and hdmi shield) and house ground.

    That does not seem right! Warranty call to Samsung I think.

    Pretty sure Rhys what could have killed the humax. Any thoughts on this anyone?
     
  5. Geerdub

    Geerdub Member

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    Dunno who Rhys is! Bloody iPhone auto spelling!
     
  6. pedro2000uk

    pedro2000uk Installer/Design Engineer

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    Does it say anything in the Humax manual about whether it has to be earthed, even though it has a no earth lead/plug? Does the flat screen have an earthed mains lead/plug.
     
  7. Geerdub

    Geerdub Member

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    Curiously the label on the humax lead says "This appliance must be earthed" even though the cable looks like twin only. Has metal earth pin. This is a pre wired and permanently attached lead.

    Samsung tv is a figure 8 kettle lead ( definitely no earth).

    Could this measurement just be a crazy ground loop?
     
  8. kerrywez

    kerrywez Grumpy Old Sat Man

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    The HDMI lead does carry a charge, but it should only be DC and very small, something like a USB does. If I were you I would give Sammy a call and ask what the score is and let them know that you have burnt two Humy boxes and do not want to burn another one.

    Regards Wez
     
  9. Geerdub

    Geerdub Member

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    Cheers Wez.

    Will call them in the morning and see what they say.
     

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