Jvc jlc32bc3000

[gilly1984]

Re: Jvc jlc32bc3000

Maybe, but if the caps he has chose have the same esr as the worn out ones would that not be a problem? Still a newbie here tom

[budm]

Re: Jvc jlc32bc3000

Beside checking the REMOTE ON-OFF pin as Tom has suggested, you might as well check the 5V, 12V, BL_ON pins just to see which signals are missing when it does not start up.

[budm]

Re: Jvc jlc32bc3000

By the way, I will not be surprised if the main board may have bad voltage regulator ICs, it looks just like VIZIO TV.

[Nam3o]

Re: Jvc jlc32bc3000

remote on/off voltage dose change when you press the power button.

[tom66]

Re: Jvc jlc32bc3000

OK, so please check the other voltages that Budm mentioned and see if they appear. If they don't, the problem is most likely on the PSU. If they do appear, the problem is most likely on the main board.

[Nam3o]

Re: Jvc jlc32bc3000

+5v all check out fine. no voltage on 12V, BL_ON pins

[tom66]

Re: Jvc jlc32bc3000

OK, so the problem is with PSU.

Can you remove the board and take a picture of the bottom, green side?

[Nam3o]

Re: Jvc jlc32bc3000

[tom66]

Re: Jvc jlc32bc3000

Something is amiss here, there is no standby power supply on this PSU, it is always on, so the 12V should be present. Please make sure you are checking the voltages correctly.

[Nam3o]

Re: Jvc jlc32bc3000

I checked form pin 4 as ground, pins 8,9,10 are no voltage.

[tom66]

Re: Jvc jlc32bc3000

Do any of the other pins have any other voltages? It is really strange for just one voltage to be missing.

[Nam3o]

Re: Jvc jlc32bc3000

all tested with pin 4 as ground.

pin1 +5.3
pin2 +5.3
pin3 +5.3
pin4 GND
pin5 GND
pin6 GND
pin7 GND
pin8 0
pin9 0
pin10 0
pin11 2.6
pin12 1
pin13 .6
pin14 .4

[tom66]

Re: Jvc jlc32bc3000

OK I think I understand the PSU now. It uses the devices on the heatsink: one as a diode, to rectify the 12V, and the other to switch the 12V on and off. Something is wrong with the second device, or the control signal isn't reaching it.

Can you read off the part #s of the devices bolted to the heatsink? (The part #s will be written on the devices.)

[Nam3o]

Re: Jvc jlc32bc3000



Smaller one
K4111
1L

Larger one
GBU406
LT 1220



06LU3
07N65GX



On the right
40N03GP
119191

Left
LT 1211
STPR1020CTW

[Nam3o]

Re: Jvc jlc32bc3000

I found the data sheet for the STPR1020CTW

[tom66]

Re: Jvc jlc32bc3000

Here's the datasheet for 40N03:

http://pdf1.alldatasheet.com/datashe...D040N03LG.html

Strange thing is, it seems to be in a different package, but it should still be relevant.

How difficult would it be to measure the voltage at pin 2 (middle), and at pin 3 (rightmost)? Use the chassis of the TV for your negative lead.

[Nam3o]

Re: Jvc jlc32bc3000

403N03 from left to right .1, 18.7, .1
stpr1020ctw left to right 0, 17.2, 0

[tom66]

Re: Jvc jlc32bc3000

OK, there is 18.7V on the DRAIN, which is the input, but only .1V on the SOURCE (output.) In order to turn on it needs at least 4V more on the gate than the source. I am confused why the output is 18.7V but it could be because it is not connected to the capacitors or the main board is not loading it down.

Can you get a closer shot of the traces around the 40N03? Try taking the picture from another angle... I need to see where the traces go.

[Nam3o]

Re: Jvc jlc32bc3000

Ok here you go

[tom66]

Re: Jvc jlc32bc3000

OK, I think I understand the design somewhat. Next question do the pins on the 40N03 change state when you press the power button?