Just noise and low voltages

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patrick
Posts: 3
Joined: Mon Oct 31, 2016 2:35 pm

Just noise and low voltages

Post by patrick »

Hi all!
After finishing soldering work with my ds0138 kit, I got next two problems: noise on LCD and low voltages on the board.
Noise shows all time and I did not touch any thing with cpl...even fingers.
My volatages are: input v - 9,5v
AV- | -4,0
AV+ | 4,15
3,3v | 3,07
5v | 4,25
V1 | 0
V2 | 1,31
V3 | 3,5
tlvl | 0.85
V+ | 5,7
The noise and serial number at photos below
http://www.picshare.ru/view/7743452/
http://www.picshare.ru/view/7743454/
Please help!
jyephpbb
Site Admin
Posts: 8
Joined: Wed Feb 20, 2013 1:12 am

Re: Just noise and low voltages

Post by jyephpbb »

The power supply seems can not source enough current. The effective voltage was only 5.7V which is too low. Can you try with power supply of larger current capacity?
patrick
Posts: 3
Joined: Mon Oct 31, 2016 2:35 pm

Re: Just noise and low voltages

Post by patrick »

Thank you for answer. Fortunately, voltages become good when i plugged 12 v instead of 9v. But noise still continue. Any suggestions?
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: Just noise and low voltages

Post by jye1 »

Can you post photo showing the noise with higher timebase (e.g. 1ms or higher)? 2s is very slow. The shown waveform might be the random data in memory came from power up.
patrick
Posts: 3
Joined: Mon Oct 31, 2016 2:35 pm

Re: Just noise and low voltages

Post by patrick »

This is a photo http://www.picshare.ru/view/7746720/
Note: cpl does not touch anything.
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