toshiba 32AV500U LCD inverter ?

digitalscorpion · Guest

LCD model: 32AV500U
Has 2 inverter PCBs, Master and Slave. I have service manual. How can I go about finding which PCB is defective? Nothing visually bad. Does LCD need both functional to work? Any hints in right direction greatly appreciated.

jts1957 · Joined: 24 Nov 2008 Posts: 778 Location: Far, Far Away

What is the "Complaint?"

digitalscorpion · Guest

there is no backlight...
already diag'd to the source.... just wish I had more info from this point. No individual PCB schematic. No way to determine if both master and slave inverters are shot or just one. If so, does this LCD TV require both....?

jts1957 · Joined: 24 Nov 2008 Posts: 778 Location: Far, Far Away

Or Bulbs?
Make comparative resistance readings of primaries / secondaries of transformers - one may be open.

minnie · Joined: 18 Aug 2005 Posts: 2510 Location: Hell

32" should just be one.

digitalscorpion · Guest

There are two different revs/versions. One has single, one has dual (master/slave).

Still havent fixed, any more help out there? :/

Dan the TV man · Guest

More bad news,it may not be inverter boards.It could also be t-con(lcd control board)over screen,Id replace capacitors in both inverter boards,and see what that does.you may have to replace all 3 boards.

calleriq · Guest

my toshiba 32AV500U HDTV has green light but noting on the screen, what could posible wrong? Any suggestion, idea? please help, thanks

Dan the TV man · Guest

Do you have sound ,and no picture.Probably inverter board(s).If you have no sound or picture,check for bulged capacitors in the power supply.If the power supply works you probably need a main board,also called a scaler board,or tuner board.The one the tuner and RCA jacks on it.

bradandjaya · Joined: 12 Oct 2009 Posts: 3

A neighbor was throwing this 1.5 year old HDTV away... Now I know why.

Looking at the inverter boards, the master has had the 300uF capacitors and mondo transistor replaced at some time. The board is getting 24V on pins 1-5 of connector 1, and fuse appears to be in original, un-blown condition.

Other than indications of the above repairs, everything looks ok visually. I will check the transistor inputs to see if one is open, as I believe that is the issue.

Any ideas on how to get a supply of transistors (marked 331 81BHK)? Or is there a longer term fix to keeping this device working?

Brad