Repair thermoelectric cooler

Discussion in 'The Projects Forum' started by SergioR, May 25, 2015.

  1. SergioR

    Thread Starter New Member

    May 25, 2015
    Hello guys.
    I´ve been reading your posts carefully as I have the same failure in the power supply of my wine cooler: it doesn´t start whn plug to AC, but it does if I disconnect the Peltier module (originally failed, but replaced by a new one!). My PSU looks similar to the ones in the pictures of your posts, manufactured by Foshan Hanyi Computer P/N 0757-83835908. So far , I´ve repalced both transistors 13005, TL494 controller, schottky rectifier, and all the electrolythics. But still not working.

    Any idea of what else could fail in this kind of power supplies?

    Hope someone could help!
    Regards from Argentina,

    <Moderator's note: Better to start with a fresh thread so you get more views. The referenced pictures are below.>[​IMG]
    Last edited by a moderator: May 26, 2015
  2. wayneh


    Sep 9, 2010
    That's curious. With the module disconnected, do all other functions appear to work? Fans, control panel, LEDs on the PCB, etc?
    What is the voltage at the module socket when it is disconnected?
    I'd look hard at the module to make sure it can produce cold on one side and hot on the other, and make sure the cold side is facing the right way.
  3. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015

    The symptoms clearly point to excessive TEM current drain -- That said I have never encountered a 'shorted' TEM...

    To make certian try loading the SMPS with a 'stiff' load exhibiting marked 'inrush' (e.g. an incandescent running lamp bulb)... It's possible that the SMPS has experienced an (isolated) failure of its 'soft start' feature...

    Best regards and good luck!:)
  4. Ivanruiz

    New Member

    Aug 10, 2015
    Hi, I have the same issue in my wine cooler power source, but in my case one of the components has totally burnt and after read this post I have an idea of which component is, I think is the NTC Thermistor, I see in your photos that the PCB is the same model but the distribution of the components is a little different so I guess the thermistor is the same, can someone give me the part number or the value of the thermistor?

    Thank you in advance!
  5. SergioR

    Thread Starter New Member

    May 25, 2015
    I´ve reading comments in this forum and others reporting similar failures as mine (fridge/wine cooler will start withuout peltier cell connected, but not with it connected) and cannot find a reasonable cause for such malfunctioning, yet. I believe we should discard failed components in the "normal working" part of the circuit as it works regularly when the TEC is connected after the PS has started. Rather we should focus on the starting components of the circuit. The question is "what components work when starting the PS?". I´ve cheched the ones associated to pin 4 of TL494 IC, but not find them as failed. More ideas??