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Old 12-09-2021, 01:43 AM   #62
Ierwin
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Join Date: Jul 2017
City & State: Braunschweig
My Country: Germany
I'm a: Knowledge Seeker
Posts: 57
Default Re: Panasonic TX-P50STW50 Power Supply no 5V (was clicking)

All the latests tests I had done with the IC501 fully connected so since you mentioned reconnecting it, I took it out in the first place.
And this time I really took it our completely. I think I should have done that earlier because all my attempts to measure around it by cutting lines on the board just messed it up. Still to a point where all the lines are okay, it just doesnt look as good.

So without the IC501 I get 9.8V where Vin would be.

I realized I made a mistake yesterday by putting the Load resistor in Series with my Voltmeter. Of course it has to be in parallel

So now when I put the 15Ω load between Vin and Gnd of IC501 the voltage drops significantly to 3.5V. With the 35Ω it drops to 4.2V.
So I thought there was a load dependant voltage drop on the second supply.

Knowing my stupid mistake with the measurement I wanted to retest the 15V line with a load in parallel, but found it wasnt there anymore. And now the 9.8V on Vin are gone too.
To my understanding of the Block diagram that is because without IC501 RL100 wont switch.
I guess when I measured earlier it was still closed on the charge of some cap and I still dont know if the voltage really drops.

I need to do more testing

Last edited by Ierwin; 12-09-2021 at 01:53 AM..
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