27″ LCD TV repair

Introduction

I received a broken 27″ Prosonic LCD TV from a friend, it was on the way to get trashed if I did not want it.

Prior experience told me to accept this offer and see what it would take to repair it.

 

Safety

WARNING!: Working with electricity is dangerous, all information found on my site is for educational purpose and I accept no responsibility for others actions using the information found on this site.

Read this document about safety! http://www.pupman.com/safety.htm

What to look for

I knew from my friend that the TV would not turn on at all, so problem is already located to the power supply before even opening up the case.

Upon opening the TV and looking at the power supply board, there was no doubt where the problem was. Fuse is blown, the off-line driver IC is blown to pieces and a large filtering capacitor does not look too good, some leaking have occurred.

Capacitor was changed to a new used one with same capacitance but higher voltage rating, its usually when capacitors are used right on the edge of their ratings that they fail.

Fuse was easy to replace to one of same value.

Replacing the IC was a bit more tricky as the writing was blown away. Luckily the power supply board had some serial numbers, writing etc. that I could search for on google.

What I found was a vendor selling new power supply board and they had a high resolution picture uploaded with a zoom function, so it was easy for me to see that the IC was a TNY265.

Finding this on ebay turned out less fortunate, it would cost around 10 Euro for a new one shipped from Hong Kong.

So I looked up the data sheet and found out this IC was a part of a series of off-line drivers in a range of different power output capabilities. The TNY266 was just a little bit stronger than its smaller counter part, so I ordered one of those for 1 Euro from Hong Kong, now it was just to wait for that IC to arrive.

After replacing the IC the TV once again lives!

 

3 Responses to 27″ LCD TV repair

  1. Pingback: Another TV lives again! | Kaizer Power Electronics

  2. Alex says:

    Nice one Mads, Looks like your friend owes you a few beers ( :

  3. Nemo says:

    hi my friend,
    i have problem with connecting my surface tablet to prosonic tv. i hope you can help me.
    i booth adapter for surface hdmi and hdmi cable. I am trying to adjust, resolution…but nothing. i don’t have control remote for tv but i can manualy put on hdmi.
    when i change in devices on ‘duplicate’ i have no sound on tablet but screen is blue and say dvi 60hz..
    please help if you can
    all the best
    Nemo

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