Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical fuse.

[Dang]

As the title states, I'm specifically after the ceramic cap at CE17, all the readable marks have been burnt off accept for **1k, the main cap CE10 also shows signs of damage. I can't quite tell if it's the main cap that blew or the ceramic but both will be changed. I'm not too sure on the fuse type either, whether it's a slow blow or a fast acting type, there is an "S" on it so it's a fair guess to say it would be a slow blow but I don't know for certain. If anyone can help with a schematic or able to tell me what I need then that help would be very appreciated, thanks, Andy.

[budm]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

That is more likely the snubber cap that is connected between Source and Drain pin, 1KV min rating. I will have to look through some the SCH to see what that value should be.
You can see how it is used Toshiba schematic 42HL196 TV

[Dang]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

OK, thank you for the help.

[budm]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

BTW, remove that cap and measure the resistance between the Source pin and the Drain pin, then also check the very small value (<1 Ohm) resistor between Source pin and Ground to see if that resistor is open or not.

[Dang]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

BTW, remove that cap and measure the resistance between the Source pin and the Drain pin, then also check the very small value (<1 Ohm) resistor between Source pin and Ground to see if that resistor is open or not.

Measured the resistor(RE13) directly behind the STRW6765 and indeed it is open, I was getting a reading of 488ohms from the mystery snubber cap but now that it's removed it just shows open, no reading what so ever, any thoughts?

[Dang]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

My guess at this cap is 471k@1kv>, is this 471pf or 47pf? I have found conflicting information and can't quite find anything universal on this like resistor colour bands, any ideas?

It seems "K" can also be a tolerance indicator??????

[budm]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

470pf, K = 10%. I would go with higher voltage like 2KV.

[Dang]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

Just for clarity, and if it needs confirming please, the PCB mounted fuse has CQ MEF, there is also a variant with a slight change to the lettering, CQ MET, the "F" is for FAST ACTING, the "T" is for TIME LAG.

[Dang]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

Snubber cap definitely a 471K, 2KV.

[budm]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

Fuse:
http://www.mouser.com/ProductDetail/...cg9hrSwHthY%3d

[Dang]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

Cheers budm, exactly what I ordered from Ebay, managed to get 10 for £3.

Tested everything else I could and nothing else seems blown, Thursday will be the test, fingers crossed.

[Dang]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

All parts received and fitted and all seems well, the cap was changed for one off an old Samsung PSU, some slight modding was needed to affix the wall mounting plate, this was needed due to the extra length of the 450v, 150uf cap, so some slightly longer screws and 4 washers aside cured the problem, thanks again budm, you were a big help.

[budm]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

Glad to hear it is working. BTW, did you get the correct resistor that went open also?

[Dang]

Re: Toshiba 37WLT68 PSU V28A000177A1, blown main power cap, ceramic and cylindrical f

My mistake, tested fine, I had the DMM on the wrong setting. Only the fuse, snubber cap and main cap needed to be changed, once again thank you, Andy.