Riddled TV Repair Forum

TonyC1 · Joined: 17 Mar 2009 Posts: 71

Just stopped working - no smoke no flashing codes????
It was a nice 42 inch LCD -checked fuse -ok - I also removed & checked all the caps on the power supply - All seem good (although there were two reading low - 1000uf 35v - there are a grp of 3 on the secondary portion of the board - one read 990 but other two were 975 & 965 - is this significant??)

Any help to fix this is greatly appreciated! I have read that they are tough to get parts for.

FYI - not trained in electronics but did fix a previous tv based on this website & discussion with a couple techs - especially Jesse.

Google

JTS1957 · Joined: 21 Jan 2009 Posts: 1331 Location: Far, Far Away

NOT significant. Bulging/Physically Leaking/Value is not only defects a cap can have.
Did you replace all of the following (less than $10.00)?
CS21 1500ufd 16Volt, CS22 1000ufd 16Volt, CS28 100ufd 25Volt, CS18 100ufd 25Volt, CS23 680ufd 25Volt, CS8 680ufd 25Volt, CS19 1000ufd 35Volt, CS25 1000ufd 35Volt, CS7 1000ufd 35Volt & CS24 470ufd 35Volt.

TonyC1 · Joined: 17 Mar 2009 Posts: 71

You have a point - I may as well replace them all just to be sure. I'll let you know what happens.

Thanks

Who do you recommend to buy these from?

kuhurdler · Joined: 28 Dec 2006 Posts: 2571 Location: Overland Park, KS

mouser or digikey

TonyC1 · Joined: 17 Mar 2009 Posts: 71

CAPs replaced - All but the very large one(not on your list - 220uf 450volt - C1) - see pict where tape is - blue
Still a no go -only blue light on front - no pict - no sound

I want to test to see if the outputs to the cables of the PS board are ok so I took picts of them - To test the voltages labeled - where do I put my meter ground & to which pin should I get 24V or 5V or 18V as they are labeled? All of them in the 24v area? etc

DCV I presume?

Thanks again for any advice.

Google

TonyC1 · Joined: 17 Mar 2009 Posts: 71

Here is the other pict of cable labels

JTS1957 · Joined: 21 Jan 2009 Posts: 1331 Location: Far, Far Away

GND = ground.
5Vs should be 5 volts Stand-by (there all time set plugged in)
5V should be 5 volts (there with Set Running)
There is also a On/Off voltage and a backlight brightness voltage (pix slightly out of focus hard to make out).

18V & 24V should be 18 volts & 24 volts (there with set running) Reference their own GND just for convenience.

TonyC1 · Joined: 17 Mar 2009 Posts: 71

So I got a new power supply - now I have a problem - I forgot to label the cables from the side panels - CNS3 & CNS 4 - which goes to the left/right side??? Their connectors on the power supply are the same. If I guess wrong what will happen? anyone with schematic - help!!

Thanks!

JTS1957 · Joined: 21 Jan 2009 Posts: 1331 Location: Far, Far Away

Look on foil side at connectors - I think you'll find they're in parallel. Cool

TonyC1 · Joined: 17 Mar 2009 Posts: 71

Well I got a replacemnt power supply from shopjimmy.com - it does not appear to be putting out voltage either. I have been taking the voltages with the board on the bench & not connected to the tv in any way- is this correct?

The 24 volt (CNS3 & 4)& 18 volts (CNS2) - both show nothing & 5volts CNS1 ( only showing 2.5 mvolts)- exception is the 5 volts on CNS1 (small label on left side of connector) is showing 5 volts. This is the same as my orig PS.

When connected to tv, the upper board (non power supply) does show a small red LED on & the power light of tv is lit (Blue). No response to power button or remote.

Any suggestions?

Thanks
Tony