Samsung UE40EH5000K Dead No standby light

[london-freddie]

Hi guys just got this Samsung UE40EH5000K dead, easy fix No
Quick check dead no power dead
found one bad cap 200v 47uf replaced, still no standby light
removed mainboard powered up and backlights came on
Diode DQ951 showed as short on board, removed it and it tested ok replaced with new diode
Any ideas where I should now look, seems like a power board problem to me, but hey I may be wrong

[london-freddie]

Re: Samsung UE40EH5000K Dead No standby light

Just checked output pins on power board, all look ok to me BUT am I wrong
1 13v
2 3.1v
3 13v
4 13v
5 13v
6 2.9v
7 13v
8 gnd
9 gnd
10 gnd
11 5.3v
12 5.3v
13 5.3v
14 3.1v

[dick_barton]

Re: Samsung UE40EH5000K Dead No standby light

QD951 looks as though it's a general purpose 1Nxxxx version diode. What was the original diode number?

[london-freddie]

Re: Samsung UE40EH5000K Dead No standby light

just checked the small on/off led toggle switch board there is no 3.3v there which comes from the mainboard

[london-freddie]

Re: Samsung UE40EH5000K Dead No standby light

Uf4007

[london-freddie]

Re: Samsung UE40EH5000K Dead No standby light

should I be looking at the mainboard ???

[budm]

Re: Samsung UE40EH5000K Dead No standby light

just checked the small on/off led toggle switch board there is no 3.3v there which comes from the mainboard

Test with Ohm meter on the 3.3V line that feed the switch board to see what you will get.

[london-freddie]

Re: Samsung UE40EH5000K Dead No standby light

update on this tv, the 3.3v line on mainboard def has a short to ground, spent hours trying to find the short, have now given up and last night ordered a used mainboard for 20, hope this sorts it out

[dick_barton]

Re: Samsung UE40EH5000K Dead No standby light

Uf4007

What was the original diode number and what did you replace it with?

[london-freddie]

Re: Samsung UE40EH5000K Dead No standby light

Update on this tv, replacement mainboard fitted today and TV is working Result, thanks guys for the help