VIORE 32" - Power board problem?

[sansonet]

Re: VIORE 32" - Power board problem?

what about the wiring going to the power button on the front of the tv? did you look at that? and where does that connect on the power board?

Power button wiring and led/infrared sensor are connected to the main board, it is black wires on the bottom (in reference to the picture in my first post)

[sansonet]

Re: VIORE 32" - Power board problem?

even so it still isn't turning on and showing a backlight and picture. does it have sound or no? did you check just the caps or did you check the diodes and mosfets?

Checked caps and few other components on that side, but not all of it. This board is not easy to work with because heatsinks covering lot of components. I would rather get a used one for around $20, but I want to be sure it will fix a problem.

[philliesfan30m]

Re: VIORE 32" - Power board problem?

did you check r92? if so what do you get?

[sansonet]

Re: VIORE 32" - Power board problem?

Onboard test - R = 42

[philliesfan30m]

Re: VIORE 32" - Power board problem?

what readings do you get on the transistors and diodes on the heatsinks? q1,2,3 etc. d1,2,3 etc.

[sansonet]

Re: VIORE 32" - Power board problem?

what readings do you get on the transistors and diodes on the heatsinks? q1,2,3 etc. d1,2,3 etc.

I removed and tested just 2, I think it was something like dualdiode 1, 2, 3.

[sansonet]

Re: VIORE 32" - Power board problem?

I have 32" Magnavox panel with bad screen, but power and everything else works fine. Maybe it can be wired somehow to test it? All connectors are different.

[philliesfan30m]

Re: VIORE 32" - Power board problem?

what are the numbers on q1,2,and 3 and d1,2,and 3? and how did you test them?

[sansonet]

Re: VIORE 32" - Power board problem?

I used component tester and I can't remember numbers right now. I tested when they was off board.

[philliesfan30m]

Re: VIORE 32" - Power board problem?

what type of component tester? i mean what are the identification numbers on q1-3 and d1-3. you are positive they are good? do you have a multimeter?

[sansonet]

Re: VIORE 32" - Power board problem?

One like this http://www.ebay.com/itm/NEW-TRANSIST...-/400483229357
When they are not good, tester says "failed device" or gives weird readings like from just 2 probes instead of 3 and detects it as capacitor, etc.
I have multimeter too, but I don't want to unsolder those again.
What are the chances that problem is with power board and not something else? I really prefer to just replace power board because it seems too much hassle of detecting failed component on it.

[vinceroger69]

Re: VIORE 32" - Power board problem?

http://www.ebay.co.uk/itm/COBY-TFTV3...item3cd8bd871a

[philliesfan30m]

Re: VIORE 32" - Power board problem?

if you just want to buy and replace thats ok i thought you wanted to narrow it down and fix it....

[philliesfan30m]

Re: VIORE 32" - Power board problem?

you can check components with a multimeter without desoldering them it just isn't as accurate and could give false readings but if the part is failed you can most likely tell by the readings. i am no expert but every tv i fixed so far i never desoldered any components to figure out which 1 was bad just using a multimeter most of the time you can figure it out

[philliesfan30m]

Re: VIORE 32" - Power board problem?

and you could check the ones under the heatsink by testing the bottom of the board where the leads are to test if you can't get to them under the heatsink... just saying

[sansonet]

Re: VIORE 32" - Power board problem?

and you could check the ones under the heatsink by testing the bottom of the board where the leads are to test if you can't get to them under the heatsink... just saying

I tried it, but with tester many times it says "failed" and only when they unsoldered it gives correct readings. I'm not sure how to test those with multimeter.
I got tester for caps mainly because I can't test them with multimeter and onboard. In my experience 50% of times failed caps looked normal, not bloated, etc.

[sansonet]

Re: VIORE 32" - Power board problem?

http://www.ebay.co.uk/itm/COBY-TFTV3...item3cd8bd871a

Yes, I saw board on ebay, even cheaper in US locations, but I want to be sure that problem is with board before I'll spend money on it.

[sansonet]

Re: VIORE 32" - Power board problem?

if you just want to buy and replace thats ok i thought you wanted to narrow it down and fix it....

I would like to, but if this too much hassle and hours of dealing with it, I would rather buy board.

[philliesfan30m]

Re: VIORE 32" - Power board problem?

if you want to buy a board i would say the power board is bad...but if you have a multimeter handy i would check some of the diode and transistors

[sansonet]

Re: VIORE 32" - Power board problem?

I just tested another one D4 on heatsink, not sure how to read it, but I used guide I found on this forum:

7.1 Voltage regulators
-------------------------

Voltage regulators (U designation) can be bad. They can be shorted or output the incorrect voltage. The test described below only tests the former.

If you have a manual range multimeter, set it to 200 ohms (two hundred). You can test voltage regulators "in circuit" for shorts by (power off and unplugged)

a) black on pin 1- red on pin 2 - record ohms
b) black on pin 1- red on pin 3 - record ohms
c) black on pin 2- red on pin 3 - record ohms

If any ohm reading is less than 30 ohm you might have shorted voltage regulator. Remove from circuit and repeat the tests to verify.

This one called "Power Rectifier" http://elcodis.com/parts/376941/MBRF20H150CTG.html

Results -
a) 0.7-0.8
b) 167
c) 167

Is that means this one is bad?