Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

[ALR]

I have this Toshiba 40RV525RZ with Power supply FSP245-4F05 that was took out by a lightning storm. No Standby voltages,etc Completely dead. I know a little bit but learning a lot so I'm not 100% where to look/check but I believe I found a bad Rectifier.

Blown Ceramic fuse, replace and instant blow. So I tested the bridge in circuit and pulled it out. In Diode mode, I get OL all the way across one way and the other way, I get .53, .52 and then .98 This is a bad rectifier, correct?

The two MOSFETS on the heatsink closest to the AC and fuse all read ok I believe. .5 with negative on the base(middle pin) and positive on the right leg. Both FETS read .5 That means it's good, right?

I noticed on the secondary side, the MOSFETS(3) don't read like the other 2 on the primary side, is this normal? I get .14, .14 and .18 by testing neg to base and pos to right leg.

I also checked the biggest diode by the caps on the SEC side and it's reading .16

Is this normal? Sorry, don't have a camera to take good quality pictures yet.

I am not even sure I'm reading the other components correctly? lol What are these solid black looking diodes with no bands or markings?

Basically what I really need to know is what are the first things to check on issues like this on power supplies after checking the voltages on the connectors? Fuse, Bridge, Diodes, Caps?

Thanks in advance!! Ps, I'm stuck trying to troubleshoot/repair on this board because EVERYONE is sold out of a new one. =/

[Agent24]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Before you start, remember that lightning strikes have a habit of blowng all sorts of things in weird and wonderful places...

Anyway, to test the bridge, refer here: https://www.badcaps.net/forum/showthread.php?t=27898 Also you can test the single diodes the same way

To test MOSFETs, try this: https://www.youtube.com/watch?v=gloikp9t2dA

Concentrate on the primary side first. That is where you get problems that blow the fuse.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Yeah, I think I have found about 10 or so shorted parts on board(both HOT/COLD sides) ranging from bridge, MOSFETS, resistors and those black diodes with no labeling...I think lol Some resistors I'd get a reading and some other resistors, I wouldn't really get anything, it'll go basically to 0001 to 0000, that means bad right?

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

I found a good pic of the board from shopjimmy.

Can someone help point out the parts that would usually go out with a power strike? Also, next to the big caps, those solid black looking diodes, what are they called? How would one buy a replacement for one of these if there is no part #? I can't find a schematic for this board either.

I figured there isn't too many parts on this board, shouldn't be too hard to find the cause, replace, repair.

[budm]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

'FBxxx" they are Ferrite Bead (small inductor), not diode.
Good clear pictures of the bottom side of the boards? Instead of keep blowing the main fuse, you can use 75~100W lamp in place of the fuse, when the lamp stays bright without going dim, that will indicate the board still has shorted circuits.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Thanks. I'll try and get some uploaded but I'm using cell phone so it may suck. I did just go over the bottom and found a very tiny solid black SMD that looked burned up a bit.

Doesn't have any coloring/labels other than small black but sticks up a bit more than the others. It's basically under the lightning bolt on the power supply. I'll try and get some good pics of the bottom so you can see what I'm talking bout. Don't know what I'd replace it with since there is no numbers on it.

Also, those ferrite beads, do they usually go out and do you test on diode mode or ohms? Thanks again for the help guys.

[budm]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

The Ferrite Bead Inductor is just a piece of wire fed through the ferrite bead, it will just shows up on the meter as low resistance since it is just a piece of wire.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Oh okay. Thanks for that info. So I guess don't pay attention to those then? I'm in the process of trying to get a few pics I just took uploaded.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Not sure how well they will show up but took a few diff pics.

[budm]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Pictures are out of focused for me to trace out those traces for me to draw up the diagram.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Damn. I don't have a digi camera Hmmm I'll figure something out. On that lamp test, just use a 100w reg light bulb and place it on the fuse holder?

[budm]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

'just use a 100w reg light bulb and place it on the fuse holder' Yes.

[budm]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

OK, list one end of the TVS first and see if the lamp will stay on full brightness, if it it does, the lift one end of those two FBxxx legs and see if the lamp will still stay on bright. you can run the board by itself, no need to connect it to other board.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Will a 75w or 150w bulb work?

[budm]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

75W will be fine.

[Agent24]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Yeah, I think I have found about 10 or so shorted parts on board(both HOT/COLD sides) ranging from bridge, MOSFETS, resistors and those black diodes with no labeling...I think lol Some resistors I'd get a reading and some other resistors, I wouldn't really get anything, it'll go basically to 0001 to 0000, that means bad right?

You need to test parts out-of-circuit which means for 2-lead parts desoldering at least one lead. If you don't do this you can get false readings from other parts in parallel.

Resistors typically blow open rather than go shorted. But if they were in parallel with say, a shorted MOSFET, it would read 0 Ohms if you measured in-circuit.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Thanks guys. Only found a 60w so I'm gonna give that a go after the kids get to bed. Hopefully, I can get something figured out tonight on it.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Quick ? Do I need to install the faulty rectifier for this to work? Did a quick test and the bulb didn't light up. Forgot I took out the rectifier and I'm using a 60w if that matters or not.

[ALR]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

Well, I soldered it all back together and still nothing. Wanted to see if the big caps were getting juice and it's showing DC 11. and the other was really low and stopped at about 1.5 I know when I first got it, they had juice and I discharged them and all was good.

[Agent24]

Re: Toshiba 40RV525RZ-No Power/Standby-Power Supply Help!

If there is no rectifier in the circuit then there is no power getting to anything, so it won't draw any current - and thus your lightbulb won't come on.

There is no point putting the shorted rectifier back in. You need to put a new rectifier in and do the lightbulb test again.