How do i solve this problem?

Discussion in 'General Electronics Chat' started by Coefficient, Mar 28, 2013.

  1. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    Hello,,,
    i just hope i am not going against the rules of this site.
    I don't know if anybody here had experience this problem and should please guide me through..
    i have been experiencing a "searching for signal" problem on my dstv 1110 decoder,initially i thought it could be a technical problem arising from my dish allignment but it isn't so,i had to take it to a Multichoice Office only for them to tell me to pay a token amount of money for repairs which i consider highly exorbitant,i do repairs but this problem is beyond my scope to correct..I would be glad if anyone would give me a helping hand to carry out this repair...Thanks in advance
     
  2. timescope

    Member

    Dec 14, 2011
    298
    44
    How did you check your dish alignment and signal strength ? Use another receiver to make sure that the signal is good. The LNB or cable may be defective. Water may have got into the LNB or cable if the connection was not sealed properly.
    Have you tried to reset the decoder? Make sure that the Home Network Frequency and symbol rate are set correctly in the installation menu.

    dishtracking.com has more information.

    Opening the decoder may void the warranty and I would not advise you to attempt to repair the main board of the decoder.

    The power supply unit is repairable.

    Timescope
     
    Last edited: Mar 28, 2013
    Coefficient likes this.
  3. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    I am an installer,although with a one year experience,i have checked another receiver with my dish and it works fine,could this problem be from power supply unit of the decoder or from the main board or both...I would be grateful to know if it is repairable or not to enable me plan ahead...Thanks for any assistance
     
  4. timescope

    Member

    Dec 14, 2011
    298
    44
    The power supply is repairable. First check the supply visually for defective components like burnt resistors or swollen capacitors. A common fault with the power supply is C10, 470uF 16v. The attached image shows the difference between a good capacitor and a failed one.

    [​IMG]

    More details can be found at mybroadband.co.za

    Timescope
     
    Coefficient likes this.
  5. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    Failed Capacitor(c10) is mostly power unit problem which i know it can easily be repaired but can power supply problem cause this "searching for signal" thingy....The happiness of any technician is the ability to do it himself..I will be grateful for any help rendered
     
  6. timescope

    Member

    Dec 14, 2011
    298
    44
    Yes, failure of C10 can cause this problem, check the link to mybroadband.co.za where the same problem was solved by replacing this capacitor.

    Timescope
     
    Coefficient likes this.
  7. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    I will check the link right away and will get back to you soon.....I appreciate
     
  8. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    Hello Timescope,i have changed capacitor C8,C9,and C10 respectively but yet,i didn't get it work,do i have to change all the capacitors in the power supply unit?...Meanwhile,my Lnb input is generating between 13volts and 18.72volts when tested..Is there something i am not doing right here?.......Please,point me to the right direction..Regards
     
    Last edited: Apr 5, 2013
  9. timescope

    Member

    Dec 14, 2011
    298
    44
    Hi Coefficient,

    What is the error number displayed on the screen ?

    Measure the output voltages of the power supply to confirm that it is working properly.

    You could also try another power supply from the same type of decoder.

    Have you Reset the decoder to default values ?

    Check the Home Network frequency, symbol rate, polarity etc.

    It could also be that the tuner on the main board is defective.

    Timescope
     
  10. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    Hi Timescope,
    I really appreciate the way you have been helpful and as well patient with me..The error message is that the decoder is stuck on scan displaying zeros all through,i have measured the power supply output voltages and its okay...It baffles me when the LNB input on the decoder is giving out voltages,yet it does not fill bouquets...If the tuner is defective,do you think this voltages produced by Lnb input of the decoder won't be affected? And again,can this tuner be repaired?...Pardon me as i am new to electronic repairs...Thanks once again
     
  11. timescope

    Member

    Dec 14, 2011
    298
    44
    Hi Coefficient,

    Please answer all the questions I asked you in the previous post.

    What are the settings in the Home network ?

    Menu > installation > 9949 etc.

    Did you change the capacitor in the attached image ?

    The main circuit board is a multi-layer board and special equipment is required to repair it.

    Please provide all the information I requested. There are several other things we can do.

    Timescope
     
  12. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    Thanks again...
    On the Menu,my Settins are thus;
    Home Network:W7
    LNB Power:On
    LNB Low and High Frequency:9750 and 10600 respectively
    Frequency:12245
    Symbol Rate:27500
    Fec:3/4
    Polarization:Horizontal
    I have changed capacitor C10 as you directed and also fixed similar power supply unit which is working perfectly with its main board but it couldn't work on the faulty decoder....I will be glad if you help me yet further....Thanks for your co-operation
     
  13. timescope

    Member

    Dec 14, 2011
    298
    44
    Hi, sorry for the late reply.

    The settings are correct.

    Corrupted software can also cause this problem.

    Some time ago, I was using two decoders with one dish by connecting the dish to the first decoder LNB in and connected the LNB out to the LNB in of the second decoder with it's LNB power switched off.

    One day, the first decoder was "searching for signal" but the signal was passing through it to the second decoder which was working properly.

    Factory reset and re-booting did not solve the problem.

    To solve the problem, I entered wrong values like 00000 or 99999 into the Home network settings. I did this several times until the decoder gave me a message that the "settings are out of range".

    I then entered the correct values and the decoder worked properly.

    I assume that the problem was caused by a software error causing an error reading the data for the frequency and symbol rate etc. It started reading the data properly when it informed me that the settings are out of range.

    Another test you can do is to connect your decoder to the LNB out of a decoder that is working (the connection I described above). Switch the LNB power of your decoder off first. Put both decoders on the same channel.
    This will identify one kind of tuner fault.

    I have never attempted to repair a decoder main board because I do not have the equipment required, schematic diagrams or the spare parts.

    Timescope
     
  14. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    Hi Timescope,
    i thank you for being my guidance all this while,May God bless you for your concern towards me...
    I will attempt all your guidelines and hope it would work and moreover give you a feedback,meanwhile,i appreciate
     
  15. Coefficient

    Thread Starter Member

    Sep 5, 2012
    37
    1
    Hi Timescope,
    i thank you for being my guidance all this while,May God bless you for your concern towards me...
    I will attempt all your guidelines and hope it would work and moreover give you a feedback,meanwhile,i appreciate
     
    timescope likes this.
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