Page 1 of 1

Wrong Voltage Noise Section

Posted: Jul 27th, '17, 12:55
by SOM
I know this has been discussed very often..

I only get 50mv at PIN1 U24
all resistors are correct in the noise section.. double checked it :)
I tried everything.. R127 with 47K .. with 4,7K .. adjustable resistor..even if i go under 1k... nothing ;(
where is my fault?
the only what i did diffrently is that i used at C31 a 1/100 instead of 1/50 .. could that be the problem?
maybe a faulty sc828r ? this is what i read here... possible to meassure something at the Q35?
would be thankful for every advice :)

best
sascha

Re: Wrong Voltage Noise Section

Posted: Jul 27th, '17, 16:50
by BedroomMusic
Power supply you are using is Ac or Dc?

Re: Wrong Voltage Noise Section

Posted: Jul 27th, '17, 17:18
by Cooper
SOM wrote:I know this has been discussed very often..

I only get 50mv at PIN1 U24
all resistors are correct in the noise section.. double checked it :)
I tried everything.. R127 with 47K .. with 4,7K .. adjustable resistor..even if i go under 1k... nothing ;(
where is my fault?
the only what i did diffrently is that i used at C31 a 1/100 instead of 1/50 .. could that be the problem?
maybe a faulty sc828r ? this is what i read here... possible to meassure something at the Q35?
would be thankful for every advice :)

best
sascha
The chip might be faulty.

Are you getting correct voltages everywhere but on that specific chip?

Re: Wrong Voltage Noise Section

Posted: Jul 27th, '17, 17:50
by SOM
I use the same Powersupply for the NAVA.
I dont understand why some people get the voltage without this mod?!
R129 Jumper
R131 100k
R127 10uf capcitor
R130 parrallel a 22pf capacitor

at least it works this way! :D

Image

I read this mod but i thought its possibel without?!

Many thanks anyway guys!!!

Best!