Sanyo DP42849 - No Power At All

[budm]

Re: Sanyo DP42849 - No Power At All

Are you sure fusible resistor R900 is good.
You need to check the DCV again this time use the negative leg of the main filter cap C821 for the black probe, the red probe goes to pin 4 of the STBY Transformer T901.
See picture:
https://www.badcaps.net/forum/attach...8&d=1450215064

[jomede]

Re: Sanyo DP42849 - No Power At All

R322 has 138 volts. 0 volts from main cap neg to 4 pin stby. how do I check the fusable resisters...ohms? withor without power.? I checked the other 2 resisters with power on across both legs Multimeter on DC200 volts and I got 0 volts. 0 volts on R900. on the 200 ohm setting I get .5

[budm]

Re: Sanyo DP42849 - No Power At All

R322 has 138 volts. 0 volts from main cap neg to 4 pin stby. how do I check the fusable resisters...ohms? withor without power.? I checked the other 2 resisters with power on across both legs Multimeter on DC200 volts and I got 0 volts. 0 volts on R900. on the 200 ohm setting I get .5

No POWER to the unit, unplug the TV, when doing the Ohms testing or you may damage the meter.
So you are getting 0V between negative leg of the cap and pin 4 of the transfomer, that means R900 has open circuit. If you check the DCV between the Negative leg of the main filter cap right now you probably will only see 160 VDC on just one of the leg of R900.

Check the resistance of R322 too.
BTW, you are measuring the DCV in the HOT DEADLY SIDE of the circuit so you should at least plug the TV into the GFCI outlet and do not touch anything with your hands! You should also read the manual on how to use the meter.

[jomede]

Re: Sanyo DP42849 - No Power At All

7-9 volts on either side of r900 with neg lead on capacitor plugged in
67.5 ohms with meter on 20m in ohms mode on resister r322 no power. anything lower on meter gives me "OL"

I know not to measure ohms with power on board...;-)

[budm]

Re: Sanyo DP42849 - No Power At All

Post 412:'.5 ohms on all 4 of the fusable resistors.
167 dc volts on the capacitor.'
Now:7-9 volts on either side of r900 with neg lead on capacitor plugged in
67.5 ohms with meter on 20m in ohms mode on resister r322 no power. anything lower on meter gives me "OL"

I know not to measure ohms with power on board...;-)"

There must be measurement error on the post 412 showing 0.50 Ohms. What Ohms scale were you using?
Now it shows 67.5 Ohms on 20M OHMS scale?
'67.5 ohms with meter on 20m in ohms mode on resister r322 no power. ' If you are 20 MEGA OHM (M OHMS) range then I do not see how it can show 67.5 Ohms on 20 MEGA OHM (M OHM) scale.
Take the fusible resistors off the board and measure the resistance.
As you can see, one end of R322 is conected to the + leg of the filter cap C821 and another end is connected to one end of R900,so basically all the legs of the resistors should show 160VDC.
It seems to me we have measurement errors. At this point I would say R322 is bad due to shorts circuit probably Q301, 302.

[jomede]

Re: Sanyo DP42849 - No Power At All

I will remeasure with my fluke auto range meter and post the results...maybe my other meter is not accurate or reading hokie

[jomede]

Re: Sanyo DP42849 - No Power At All

ok meter was bad....the flute has the following: Neg terminal from main cap to one side of R322 = 160 volts----the other side of r322 has 5 volts. neg side of main cap to R900 = around 10 volts on one side and around 10 on the other side. ( voltage is fluctuation from 7-11 volts) 1.3 ohms on the 4 fusable resisters where main 120 volts comes in.

[budm]

Re: Sanyo DP42849 - No Power At All

ok meter was bad....the flute has the following: Neg terminal from main cap to one side of R322 = 160 volts----the other side of r322 has 5 volts. neg side of main cap to R900 = around 10 volts on one side and around 10 on the other side. ( voltage is fluctuation from 7-11 volts) 1.3 ohms on the 4 fusable resisters where main 120 volts comes in.

Well one end of the R322 has 160Vdc feeding it and you have 5vdc on the other end so it means the resistor has 155VDC Voltage across R322, since R322 you indicate 1.3 Ohms, that means you have 155V/1.3 Ohms = 119A of current flowing through that R322 which is impossible!
And not only that since R322 leg that shows 5V is feeding R900 but you indicate 10V so that is impossible too, you cannot have 10V when the output of R322 is connected to R900 only has 5V. Think about it and look at the pictures of the bottom side of the board that I have marked for you.
You are still not making correct measurement. Look at how R322 connected to R900.
I think you should buy a new board at this point.