SONY kdl40s2010 no power

[trans_ponder]

Hi guys! The tv doesn't turn on, no led is lit. I got the PSU (inverter) schematic and measured in various points. The main voltages going to other boards are all missing 18v, 10.5, 15v.. But the high voltages like 400V are present. Not sure how to progress, I need your help. Any test point I should try (schematic attached)? Thanks a lot

[CapLeaker]

Re: SONY kdl40s2010 no power

Give the board a good visual over view, top and bottom. Do a preliminary check on all fuses, diodes, bridge rectifiers and transistors. Give it a whiff test and maybe you smell even something "burnt" etc.

Basically either the whole board has no power (I don't think so since you got like 380V or so on the big filter caps), or the 3.3V Standby voltage is missing on the power supply and so can't turn on the rest of the power supply. Also check the unregulated 3.3V. The schematic is nice to follow. Could be a diode, a bad cap, the optocoupler, some transistor, a bad resistor, etc. The 3.3V rail should be always on, regardless of the TV being on or off, as long as it plugged in of course.

To give you a little head start, check D6306 and C6315...

[trans_ponder]

Re: SONY kdl40s2010 no power

Thank you CapLeaker for your reply. The 3.3V is missing. I measured the diode/cap you suggested and they're ok, but I found a bad diode D6305 which is shorted. It's around the same coil/transformer so it makes sense. It's 10ERB20-TB3 a fast recovery 1A/200V diode, so I've odered the equivalent UF4004. As soon as it comes I'll change it and let you know the result. Hopefully the rest of the components are ok. Thank you!

[CapLeaker]

Re: SONY kdl40s2010 no power

Thank you CapLeaker for your reply. The 3.3V is missing. I measured the diode/cap you suggested and they're ok, but I found a bad diode D6305 which is shorted. It's around the same coil/transformer so it makes sense. It's 10ERB20-TB3 a fast recovery 1A/200V diode, so I've odered the equivalent UF4004. As soon as it comes I'll change it and let you know the result. Hopefully the rest of the components are ok. Thank you!

I am glad you found it. Also check C6309.

[trans_ponder]

Re: SONY kdl40s2010 no power

Replaced the diode and capacitor(looked ok, but just in case) and it's back to life. Thanks for all your help! Happy New Year everyone!

[DanStroup]

Re: SONY kdl40s2010 no power

I just acquired a set with the same issue. Preliminary testing indicates that D6306 is bad and allowing current both ways.

My question is this is referred to as a D1NS4-TR2 diode. When I search by that number I am finding few results. I do however find LOTS of just D1NS4 diodes for sale? Is the TR2 a meaningful designation? Or do I simply purchase the D1SN4 diode?


Thank you!

[jetadm123]

Re: SONY kdl40s2010 no power

Lettering after the main part number usually indicates the type of packaging the diode comes in. Some come as surface mount versus a through-hole design. Any schottky diode rated at 40V 1A should work fine. Just make sure it physically looks the same as yours.

[CapLeaker]

Re: SONY kdl40s2010 no power

if you want you also can put a higher rated schottky. Make sure you test that bad diode out of circuit too.

[DanStroup]

Re: SONY kdl40s2010 no power

Thanks. Picking one up tomorrow and will post the results.

[DanStroup]

Re: SONY kdl40s2010 no power

OK. Did not see a fault with D6305 so I did not replace it. I did see a fault with D6306 which was listed as a D1NS4-TR2. This was replaced with a NTE585 (that's what they said was a replacement). I also replaced C6315 and C6309 (But they looked alright).

That said, it now powers up, but I cannot get a picture. no Menu no volume and no flashing lights. But I can see the backlight!!! Any further advice?


Thanks!!

Dan

[DanStroup]

Re: SONY kdl40s2010 no power

And I just tested the old diode out of the board and it appears ok....and new diode is passing voltage both ways. Now I am really confused.

[newtothis]

Re: SONY kdl40s2010 no power

Check fuse at tcon for continuity, Also check voltage at either side of tcon fuse.

If you cant find the fuse take a good clear pic for us

[DanStroup]

Re: SONY kdl40s2010 no power

And I cannot find any Standby 3.3 voltage nor a standby light. I am guessing that something is stopping the 3.3. which, like stated above, is preventing the rest of the system to power up.

The hunt continues tomorrow!!!

[DanStroup]

Re: SONY kdl40s2010 no power

Newtothis - The only fuse I see is near the AC input. This tests fine both visually and with a meter. I am only getting one relay to click when powering up (RY6003), The other (R6001) never clicks over.

[CapLeaker]

Re: SONY kdl40s2010 no power

He meant the SMD (mini surface mount) fuses. I am not sure what your problem is, but if the power supply came on and you have backlight, the trouble is either on the t con not getting any power or something on the main board.
Pictures would be nice, then how about a listed pin out with name and voltages with the TV on and off. The connector I am after is the one that goes between PSU and the main board.

[DanStroup]

Re: SONY kdl40s2010 no power

Ahh, I found it. The T-Con fuse (CP101P) was toast. Temporary bypass and just like new. Placed the order today for a new one.

Thank you all for the advice and assistance!

Dan

[newtothis]

Re: SONY kdl40s2010 no power

Cheers for the follow up, Glad you got it fixed