Sanyo DP42849 - No Power At All

[multimeter]

Re: Sanyo DP42849 - No Power At All

going to take a bit of work if OP has no experience

dmm black probe in COM socket.red probe V MA socket

what voltage with power lead plugged in do you see on the input power cable?,measure directly off the 2 mains pins.you should see 120 ish volts there.

check fuse on circuit board,(white one),meter set to ohms,should read very low resistance or meter will beep,this indicates good fuse

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Got my meter today. Picture attached.

Also attached are pictures of PS pins, and of IC and diode that have been the culprits in other similar threads about my model.

D0951 - Tried testing following instructions that came with my DMM. I get 215 one way and "1" the other way.

IC901 - I don't know how to test this.

I now understand that the first step is to test voltage on the pins on the secondary side of the board. Is this something I can do while the television is unplugged? I'm guessing not.

I've disconnected the power cable to the main board, and another smaller cable that went from power board to main board. Photo attached.

I've had TV unplugged for a few days. Is there anything I can test while large caps are discharged?

Should I leave boards in TV or take them out?

NB: Please use plain English and avoid terminology when possible.

Thanks.

[multimeter]

Re: Sanyo DP42849 - No Power At All

d0951 is fine

part number of ic901?

you need to measure dc voltages with power plugged in but tv not turned on,all boards hooked back up

meter set to dc v, ground will be your chassis the metal casing,your black probe will go here,and the red probe to each pin in turn

mark all pins down with tests

like

pin 1 stby 5.3v

pin 2 bl_on 3.3v

and so on,,,,

do this on all the connectors you see

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Okay here I go. If I don't report back, you'll know what happened.

That IC is hard to read. A6069H SK803 23BP.

Can I use mounting screw as ground? The chassis is far away.

[multimeter]

Re: Sanyo DP42849 - No Power At All

Okay here I go. If I don't report back, you'll know what happened.

That IC is hard to read. A6069H SK803 23BP.

Can I use mounting screw as ground? The chassis is far away.

mounting screw fine..

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Oh yeah - is this my service manual?

[multimeter]

Re: Sanyo DP42849 - No Power At All

Okay here I go. If I don't report back, you'll know what happened.

That IC is hard to read. A6069H SK803 23BP.

Can I use mounting screw as ground? The chassis is far away.

this is your power ic,pin one will have a dot on the surface

count anti-clockwise,you will have to check pins 3 and 5 ,with your meter on 200 ohm resistance,report the reading back,when you have done the voltage testing

[multimeter]

Re: Sanyo DP42849 - No Power At All

Oh yeah - is this my service manual?

looks like it,lets see how testing goes.it could be a mainboard flash problem,eek

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Did the IC before plugging TV in. Is that okay?

I got 2.5 on pin 3 and 18.0 on pin 5. Not sure if I did it right, and it fluctuates with any tiny little movement of my hand.

Okay doing voltages now . . .

[multimeter]

Re: Sanyo DP42849 - No Power At All

Did the IC before plugging TV in. Is that okay?

I got 2.5 on pin 3 and 18.0 on pin 5. Not sure if I did it right, and it fluctuates with any tiny little movement of my hand.

Okay doing voltages now . . .

sorry my fault,black probe on pin 3 red on pin 5,it may need removing to get a good reading,but see what the resistance is between those 2 pins

power off and unplugged for that test

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Okay, I plugged TV in, poked black lead into mounting screw and red lead into each pin. DMM on DCV 20. Touched all pins in photo.

Got 0 on all of them. Paid special attention to STB5V because that's the only one I'm supposed to get a reading on, right? Got nothing.

I did remove the cables to make it easier to touch the pins.

[multimeter]

Re: Sanyo DP42849 - No Power At All

Okay, I plugged TV in, poked black lead into mounting screw and red lead into each pin. DMM on DCV 20. Touched all pins in photo.

Got 0 on all of them. Paid special attention to STB5V because that's the only one I'm supposed to get a reading on, right? Got nothing.

I did remove the cables to make it easier to touch the pins.

the 5 v should be there ,those readings are with the tv plugged in ,but not switched on?just double check.

then turn the tv on and do the same measurements for voltages

on both tests keep the mainboard connected,and just squeeze your probes down the side of the cables

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

sorry my fault,black probe on pin 3 red on pin 5,it may need removing to get a good reading,but see what the resistance is between those 2 pins

power off and unplugged for that test

Man, this takes a lot of dexterity.

Black lead on pin 3, red lead on pin 5 - I got a "1".

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

the 5 v should be there ,those readings are with the tv plugged in ,but not switched on?just double check.

then turn the tv on and do the same measurements for voltages

on both tests keep the mainboard connected,and just squeeze your probes down the side of the cables

Correct, I didn't press the power button.

Let me try again with the cables attached.

[multimeter]

Re: Sanyo DP42849 - No Power At All

Man, this takes a lot of dexterity.

Black lead on pin 3, red lead on pin 5 - I got a "1".

no short to ground there,there is a mosfet in there ,sort that out in a bit

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Okay, TV plugged in, didn't press power button.
DMM - DCV 20
Black lead on mounting screw, red lead poked into areas marked in photos. I pushed the lead as far in as it would go. Tried both sides of where wire goes into plastic connector.

Nothing. Paid special attention to STB5V - nothing.

[multimeter]

Re: Sanyo DP42849 - No Power At All

Okay, TV plugged in, didn't press power button.
DMM - DCV 20
Black lead on mounting screw, red lead poked into areas marked in photos. I pushed the lead as far in as it would go. Tried both sides of where wire goes into plastic connector.

Nothing. Paid special attention to STB5V - nothing.

and do the same with power turned on as if you wanted to watch tv,and measure voltage on all pins

there is a fault in the standby circuit it seems.or pfc circuit isnt working.

under the large heatsheild there is a large capacitor,can you see the legs?,and could you get your probes in there for the next test?.....

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

Repeated test after pressing power button once. Same results.

[NihonNoir]

Re: Sanyo DP42849 - No Power At All

and do the same with power turned on as if you wanted to watch tv,and measure voltage on all pins

there is a fault in the standby circuit it seems.or pfc circuit isnt working.

under the large heatsheild there is a large capacitor,can you see the legs?,and could you get your probes in there for the next test?.....

Do I have to test that capacitor while the TV is plugged in?

[multimeter]

Re: Sanyo DP42849 - No Power At All

Do I have to test that capacitor while the TV is plugged in?

you need to check it twice,once just plugged in with wall switch on and tv off,and once with tv turned right on..

but first on the black connector with the black and white mains in wires are

with all plugged in and wall switch on,but not tv on,what voltage do you read?,set your meter to AC volts this time (highest setting),need to find your voltage to see what should be on that cap when powerd up,

your in the high voltage primary section now,so be carefull!,and watch where your sticking the probes