Samsung LE40M87BDX/XEU

[sordids999]

hi guys
trying to figure out this problem cant see much wrong with the power unit but i only have to plug in the tv and it blows the house main trip fuse

any ideas ?

[tom66]

Re: Samsung LE40M87BDX/XEU

Bridge rectifier, PFC, main cap. Check all. If you want more help, you know the drill, we need pictures. Also get BN44 number off PSU and I will see if I have a schematic. I have quite a few.

[sordids999]

Re: Samsung LE40M87BDX/XEU

psu number is BN44-00167

[tom66]

Re: Samsung LE40M87BDX/XEU

I have schematics
http://www.toms-service-manuals.com/...&Search=Submit

[sordids999]

Re: Samsung LE40M87BDX/XEU

thanks for that tom ill keep for future use but i think i found the problem maybe working 12 hours on shift made me miss this

[tom66]

Re: Samsung LE40M87BDX/XEU

It's not the problem, just a symptom of the failure. Have you tested the bridge recitifer, PFC fet and main capacitor yet?

[sordids999]

Re: Samsung LE40M87BDX/XEU

now how do i do that m8 ?

[tom66]

Re: Samsung LE40M87BDX/XEU

Do you know how to test a bridge rectifier?
It's the four-legged device, right most heatsink with danger sign on it.

[sordids999]

Re: Samsung LE40M87BDX/XEU

Do you know how to test a bridge rectifier?
It's the four-legged device, right most heatsink with danger sign on it.

i see it not sure how to test it though

[tom66]

Re: Samsung LE40M87BDX/XEU

https://www.google.co.uk/search?q=ho...hrome&ie=UTF-8

[sordids999]

Re: Samsung LE40M87BDX/XEU

thanks tom
to be fair m8 would it pay me to buy a new psu i noticed just now who ever had this tv before has changed the caps proberly bulged and it looks like they have damaged the board also

[tom66]

Re: Samsung LE40M87BDX/XEU

The PSU is not going to be cheap as it is a common failure point of these sets, I do not see sense in replacing it if the fix is relatively easy to do, but I will let you judge costs.

[sordids999]

Re: Samsung LE40M87BDX/XEU

from following the video im getting a reading from both connections so im guessing i have a shorted diode

[tom66]

Re: Samsung LE40M87BDX/XEU

Number the pins 1-4 as you look at the label side, where do you see a short?

[sordids999]

Re: Samsung LE40M87BDX/XEU

im getting readings from both directions which in the video says i should not be but 2-3 is giving me a reading of 1428 the other are giving me 500

[tom66]

Re: Samsung LE40M87BDX/XEU

Do you ever get a reading under 50?

[sordids999]

Re: Samsung LE40M87BDX/XEU

no tom

[tom66]

Re: Samsung LE40M87BDX/XEU

You tested the device out of circuit I'm guessing?

On the PCB, using the previously described numbering scheme, test between pins 1-4 and pins 2-3.

The bridge appears to be good, the fault is likely elsewhere.

[sordids999]

Re: Samsung LE40M87BDX/XEU

my bad im still learning
1-2 is 46.8 2-3 0 3-4 47.7 so it seems its good
after following the video

[tom66]

Re: Samsung LE40M87BDX/XEU

2-3 measure "0" out of circuit?