Vizeo E500i AO dead with led on

[rayxoxo]

Fixing for a friend - a schematic would be helpful.
Any help welcome.
I have pulled TH280 resistor reads 750 but don't know what it should read. Thought I had found the fault with a FMW2156 schottky diode but that might not be bad at all. Might end up buying the PS board.
Thanks
Ray

[R_J]

Re: Vizeo E500i AO dead with led on

If you have the standby led on, then you should have 5.2vsb. Do you have +12v? what voltage is on CN201 pin8 Remote ON/OFF and does it change when the power button is pressed?

Where/what is TH280 ?

[rayxoxo]

Re: Vizeo E500i AO dead with led on

The board is not in the TV at this time, but as soon as I can get back to it will test the points mentioned. Also, I was ignorant as to where the test points were located until just now - after closer look at the circuit board. LOL
I believeTH280 is a Thermal resistor.

TIA for the help R-J
Ray









r-

[nomoresonys]

Re: Vizeo E500i AO dead with led on

Maybe use about a 1k resistor and jump pin 8 to pin 1 or 2, see if your voltages come up, testing board by itself.

[rayxoxo]

Re: Vizeo E500i AO dead with led on

I won't be able to get to get to the tv for about a week or so to do the tests recommended. After checking out the board will get back to you.
Sorry for the delay.

[rayxoxo]

Re: Vizeo E500i AO dead with led on

I now have the tv here at the house and can do the test. I checked the 5.2vsb. It stays on even when the led goes off.
By the way the led turns on for about 6 sec. then goes off and then turns on again for about 1 sec. if that's any help.
No 12v -
Pin 8 changes from 0 to about 3v, but not every time it is powered on.???
With 1k ohm jumper between 1 & 8 of cn201 - voltage comes up to 5.2v .

[nomoresonys]

Re: Vizeo E500i AO dead with led on

"With 1k ohm jumper between 1 & 8 of cn201 - voltage comes up to 5.2v ." So no 12 v on 6 and 7 when jumped?

[dick_barton]

Re: Vizeo E500i AO dead with led on

Can you post a focused photo of the area in the red box.
Do you have the schematic for the power supply?

[rayxoxo]

Re: Vizeo E500i AO dead with led on

All help appreciated. No +12v - 5.2vsb OK on PS board.
Thanks,
ray

[rayxoxo]

Re: Vizeo E500i AO dead with led on

I've tested the bigger caps with a ESR - and they seem fine, I haven't tested the blue one s as yet. Also tested the diodes in the area. If that's any help.

[rayxoxo]

Re: Vizeo E500i AO dead with led on

Have not received any responses or help for over a week.

[nomoresonys]

Re: Vizeo E500i AO dead with led on

Did you do request in post #8??

[nomoresonys]

Re: Vizeo E500i AO dead with led on

Post pictures of ALL the boards, good clear straight on and one of the whole back to see how they are connected, remote troubleshooting is not always easy, even with pictures.

[rayxoxo]

Re: Vizeo E500i AO dead with led on









Nomoresonys. -
I found no 12 v was present - and ordered 2 mosfets, Q150 and Q151. If there are any others problems in that area that might be defective that info would be appreciated.
What caused the mosfets to break down? A schematic would have been helpful -
Thanks
Ray

[nomoresonys]

Re: Vizeo E500i AO dead with led on

Maybe trace out from bottom of board and see what turns them on and check that if possible, yep it's much easier with a schematic.

[R_J]

Re: Vizeo E500i AO dead with led on

Were the mosfets shorted? What is the voltage across the main cap C120? and does the voltage increase when the power supply is turned on? it should be 160VDC and increase to 380VDC. What is the voltage on JP116 and also JP113?
JP116 = vcc (20~25v)
JP113 = switched vcc (15~18v)
also post the numbers of ic120 & ic150

[rayxoxo]

Re: Vizeo E500i AO dead with led on

R_J

More strange reading. When first plugged in jp 116 read 28v and jp113 read about 33v. After plugged in for about a minutes they both read 0V - but if left plugged in no reading on either jp.

C120 -167v and on 303v

I could not find a ic 120 nor the ic 150 ?

Again I should mention that the on/off led - when pressed on white led stays on for about 6 second then goes off for about a second and then turns back on for one final second.

What area changes the higher voltage to the 12v???

Where's a schematic when you need it. LOL

I find myself jumping all over the PS board, I haven't worked on tvs for about 40 years so testing components isn't that difficult. But IC 's smc and logic arays are a big pain for us older folks.

[R_J]

Re: Vizeo E500i AO dead with led on

Are you using HOT ground (c120 negative lead) when checking JP113 & JP116? The voltage on JP116 should be around 33v as it is supplied by the standby transformer. JP113 should be around 18v and will only be there when the tv is turned ON.
I suspect you were using chassis ground when checking these, You cant do that for any voltages in the primary (note the XXXXX line on the board seperating hot primary from cold secondary)

If you look at the back of the board you will find IC120 & IC150, IC120 is likely the PFC IC which is working if the main cap voltage goes from 150v to over 303v (303v seems low, usually around 380v)
IC150 is the main drive ic that drives Q150/151 and switches the primary of the main transformer T150, this transfomer produces the +12v etc. This is a smps and the frequency the transformer operates at is around 50~100khz

[rayxoxo]

Re: Vizeo E500i AO dead with led on

I am using chassis ground, but when reading c120 I am reading it across both legs of the cap. I will try looking on the back of the PS board for ic120 & 150.
What is bothering me is the two different reading of them (jp 113 & 116)?
It seems to be the correct readings for about 30 sec to a minute and then zero. Like some part of the system works for a short time and then closes down.

I''ll try to get back to you today or tomorrow, with what I found.
Thanks again R_J

[R_J]

Re: Vizeo E500i AO dead with led on

Those voltages on JP113 & jp116 need to be checked with your meter probe on C120 negative (HOT GROUND). NOT CHASSIS GROUND.
REMEMBER that the PRIMARY HOT SIDE is LIVE, and NOT ISOLATED from the A/C line