My TV recently broke and I went to get it repaired and they said that the power board had died. I took the TV home to see if I could fix it and everything appeared to be fine. If it is a broken transistor how can I tell?



closed as off-topic by Bence Kaulics, JRE, PlasmaHH, Andy aka, Bimpelrekkie Nov 3 '16 at 9:43

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  • \$\begingroup\$ "everything appeared to be fine" - eh, so it's back working now? \$\endgroup\$ – Andy aka Nov 3 '16 at 9:22
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    \$\begingroup\$ If it is a broken transistor how can I tell? Without some knowledge about electronics, experience and the right equipment: you can't. This is not something which can be learned by asking a question on SEEE. \$\endgroup\$ – Bimpelrekkie Nov 3 '16 at 9:50

A pound to a penny says a broken TV power supply is a failed electrolytic capacitor. TV PSUs are notorious for under-rating their caps. Look at the power supply board, and see if any of the electrolytics are 'bulged' at the top. Like this

enter image description here

If any are like that, and you figure you have the soldering skills, and are willing to take the gamble of the cost of a cap or two versus the cost of your TV, then replace the bulged ones. It fixes an astonishingly high proportion of TV faults.

  • \$\begingroup\$ All of the caps look fine but I will double check tomorrow. \$\endgroup\$ – WasabiPickle Nov 3 '16 at 9:12
  • \$\begingroup\$ Even if the caps look fine it is still possible that they're not working as they're supposed to. You have to de-solder them and measure their capacitance and ESR to be sure. And even then it can still be something else entirely. \$\endgroup\$ – Bimpelrekkie Nov 3 '16 at 9:46
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    \$\begingroup\$ No, this is a quick look thang, bulged caps are bad. If they look good, then you are into proper debugging, and it could be anything, and is probably not worth the agro. See if you can source a replacement power supply board. \$\endgroup\$ – Neil_UK Nov 3 '16 at 10:07

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