Toshiba 46RV525R power supply capacitor problem

[jackal68]

Hi

i got a no power toshiba 46 LCD tv, model 46RV525R that,once I opened up the back cover, I found a cracked component. The markings on the board says TH101 but also CP101 and CP102, however, there are no markings on the actual component to tell what it is and its value. Any ideas?

[victor_cj]

Re: Toshiba 46RV525R power supply capacitor problem

TH101 he is a NTC thermistor as a 10D-20 NTC.

[budm]

Re: Toshiba 46RV525R power supply capacitor problem

Did the main fuse blow also? There is over current situation so you need to check all the power devices to make sure they are OK.

[jackal68]

Re: Toshiba 46RV525R power supply capacitor problem

Did the main fuse blow also? There is over current situation so you need to check all the power devices to make sure they are OK.

Yes, the main fuse threw as well. Now, can I check for over current without replacing the ceramic fuse? If I need to replace the fuse (which has already been ordered), can I replace the cracked thermistor with the 10D-20 NTC thermistor?

As well, I am assuming, if there is over current, as soon as I put the fuse back (with a good thermister), won't it throw again? How do I check for over current?

thanks

[budm]

Re: Toshiba 46RV525R power supply capacitor problem

You need to check the bridge rectifier, the MOFSET's, etc. Just do the search on how to those devices, the bad device will have low resistance (<100 Ohms) readings between the pins.

[jackal68]

Re: Toshiba 46RV525R power supply capacitor problem

You need to check the bridge rectifier, the MOFSET's, etc. Just do the search on how to those devices, the bad device will have low resistance (<100 Ohms) readings between the pins.

Okay. I tested the bridge rectifier (D15XB) and it seems to be good. Now I have the following which seems to be all mosfets but I cannot find any data sheet on them....any help?

Two K4 106 - ???
One W2156 - ???
Two EN220A - ???

I don't know the data sheet so i can't tell the pinout.

[budm]

Re: Toshiba 46RV525R power supply capacitor problem

Please upload the pictures of the devices.
"I tested the bridge rectifier (D15XB) and it seems to be good" What resistance do you get between the two outer pins? What resistance do you get between the two inner pins?

[jackal68]

Re: Toshiba 46RV525R power supply capacitor problem

Please upload the pictures of the devices.
"I tested the bridge rectifier (D15XB) and it seems to be good" What resistance do you get between the two outer pins? What resistance do you get between the two inner pins?

Okay, I did the test according to this youtube link below. As per the video, my reading in diode mode, is between 400-600

https://www.youtube.com/watch?v=11JPy4t36oo

When I take the resistance reading, I get the following:

outer pins - OL
inner pins - 0

is the rectifier good or bad?

[budm]

Re: Toshiba 46RV525R power supply capacitor problem

Two inner pins (AC INPUT Hot and Neutral) showing '0' Ohms? if it is, you need to remove it and test it off the board and also on the two pads of the board.

[jackal68]

Re: Toshiba 46RV525R power supply capacitor problem

Two inner pins (AC INPUT Hot and Neutral) showing '0' Ohms? if it is, you need to remove it and test it off the board and also on the two pads of the board.

I removed the rectifier and here are the results:

outer pins - OL
inner pins - OL

out pads on the board - OL
inner pads on the board - 0

The circuit board would lead me to believe that the inner pads should have no resistance between them (see picture below).

I still cannot find any info on the mosfet transistors. Any ideas?

[budm]

Re: Toshiba 46RV525R power supply capacitor problem

OK, now since I can see partial picture of the bottom side of the board, the two inner pins of the bridge rectifier are tied together that is why it shows 0 Ohms, the bridge is set up as the Voltage doubler circuit.
I need god clear pictures of the whole bottom side of the board.
BTW, the power supply is only $20.
http://www.shopjimmy.com/toshiba-750...wer-supply.htm

[jackal68]

Re: Toshiba 46RV525R power supply capacitor problem

OK, now since I can see partial picture of the bottom side of the board, the two inner pins of the bridge rectifier are tied together that is why it shows 0 Ohms, the bridge is set up as the Voltage doubler circuit.
I need god clear pictures of the whole bottom side of the board.
BTW, the power supply is only $20.
http://www.shopjimmy.com/toshiba-750...wer-supply.htm

Yeah, I noticed the cheap price of the power supply at shop jimmy as well. I will most likely get it from there....but this is just bugging me now and I want to figure it out.

I took out the the transistors w2156 and en220a and they seem bad. In diode mode, there are reading below .2 one way and OL the other. Could this be the cause of the over current?

Here is the picture of the whole bottom side:

[budm]

Re: Toshiba 46RV525R power supply capacitor problem

When I check to see if the device is shorted out of have conduction in both direction, I use Ohm mode on the meter because when semiconductor is bad it does not function as semiconductor any more but more like resistor (conducts both direction).
So take the readings and report the result as in Ohm, or K Ohms, or M Ohms.

[matt@bdtinc.com]

Re: Toshiba 46RV525R power supply capacitor problem

I just wanted to add a trick I learned to test if the board is still shorted without wasting fuses. Simply hook an incandescent light bulb in place of the fuse. If you power on and the bulb glows bright, there is still a short!

[budm]

Re: Toshiba 46RV525R power supply capacitor problem

Or make a box like this if you are going to do lots of repair so you do not have to worry about the clips flying loose from the fuse clips and get shocked or causes damages.
http://s807.photobucket.com/user/bud...?sort=3&page=1

[budm]

Re: Toshiba 46RV525R power supply capacitor problem

Check the resistance between the surge protector VS101 (Close to the bridge rectifier).
Check the resistance between S and D pin of the MOSFETs Q101, Q102.

[Agent24]

Re: Toshiba 46RV525R power supply capacitor problem

The markings on the board says TH101 but also CP101 and CP102

I would say the CP101\102 refer to the little turrets they mounted the thermistor's leads into.