Toshiba 37AV502R PSU

[foudl]

I'm working on the power supply , and i want to know if i should have the voltages (24-12-5 V) even if it is plugged only to 120v (and not plugged to the other boards of the tv.

I tried to resolder the diode d200 and when i plugged it back the ic m200 blew right off, i changed the diode and the ic but since then there is no voltages coming out ...

[nomoresonys]

Re: Toshiba 37AV502R PSU

I think you should always have the 5v, but the others might require the mainboard be connected.

[tom66]

Re: Toshiba 37AV502R PSU

If an IC on the primary blew up it probably took out a fuse. Virtually every power board will have a 5V or 3.3V standby always regardless of other connections.

[foudl]

Re: Toshiba 37AV502R PSU

The fuse is ok ,i would like to know what kind of voltage i should get out of the bridge (BD001),right now i get something like 2.4 v , if i follow the line i get to diode d203 that is open, the diode # is T2D89, i google it and can't find anything that fit .

Any clues?

[nomoresonys]

Re: Toshiba 37AV502R PSU

try taking that diode out of circuit and check it.

[budm]

Re: Toshiba 37AV502R PSU

Hard to help without seeing the pictures of the board.
What GND point did you use to measure the Voltages on the primary side?

[foudl]

Re: Toshiba 37AV502R PSU

I already took the diode out and it's open , the ground point that i use is from the primary side (where the screws attach the board to the tv frame.

[budm]

Re: Toshiba 37AV502R PSU

I already took the diode out and it's open , the ground point that i use is from the primary side (where the screws attach the board to the tv frame.

That is why your Voltage readings are invalid.
When you work in the primary (HOT) side of the circuit, the GND ref point for you V meter will be the Negative leg of the main filter cap, NOT the chassis.
When you make the Voltage measurement in the secondary side (COLD), you can use the chassis as the GND ref. for the meter since the GND of the secondary side is usually tied to the chassis GND.

[nomoresonys]

Re: Toshiba 37AV502R PSU

here foudl, allow me to post a pic. http://www.shopjimmy.com/toshiba-750...wer-supply.htm

[budm]

Re: Toshiba 37AV502R PSU

here foudl, allow me to post a pic. http://www.shopjimmy.com/toshiba-750...wer-supply.htm

Is that the exact match to your board, foudl?
I will need good clear pictures of the bottom side of the board also since SJ does not have one.

[foudl]

Re: Toshiba 37AV502R PSU

Oops ,my bad ,you're right, now the voltage out of the bridge is 168v, i can follow the voltage to the drain of Q300 (k3994 mosfet), but from there no voltage out

[foudl]

Re: Toshiba 37AV502R PSU

here you get some pics
https://www.badcaps.net/forum/attach...3&d=1420382089
https://www.badcaps.net/forum/attach...0&d=1420381965

[budm]

Re: Toshiba 37AV502R PSU

I need to see the WHOLE bottom side of YOUR board, the picture in the link does not show the whole bottom side, the pictures must be clear enough for me to trace out the connections on the bottom side of the board.

[foudl]

Re: Toshiba 37AV502R PSU

Here
http://i1298.photobucket.com/albums/...ps53598bc2.jpg

[budm]

Re: Toshiba 37AV502R PSU

OK, so let me get this correctly, if you do not have cable connected to the P802 connector, there is NO voltage on any one of the pins?

[foudl]

Re: Toshiba 37AV502R PSU

No voltage at all ,but as mention before the diode d 203 is wide open so i figure out that it is normal not to have any kind of voltage going out, i would like to know what voltage i should read on the primary side.

[budm]

Re: Toshiba 37AV502R PSU

The DCV on the main filter cap should be around 160VDC which you had verified.
Right now you need to get the 5VSTBY power supply working first.

[nomoresonys]

Re: Toshiba 37AV502R PSU

No voltage at all ,but as mention before the diode d 203 is wide open so i figure out that it is normal not to have any kind of voltage going out, i would like to know what voltage i should read on the primary side.

not sure what you mean, if you check that diode out of circuit, you should get .4 to .8, in that range, all you do since its out of cir., just put your meter in diode mode, and put a probe on each leg, then switch probes, should get ol one way and .4 to .8 the other way.

[foudl]

Re: Toshiba 37AV502R PSU

Diode out of circuit shows OL on my meter on both side ,so it's obviously open.

[nomoresonys]

Re: Toshiba 37AV502R PSU

you have to be careful working on primary side of power supply, HIGH VOLTAGE, can be deadly, so be sure and double check what you do, with budm or one of the other pros.