DSO3064 Channel 4 Inaccurate

Bauldy

Hello,

I have a DSO3064 which I purchased off of Ebay approx 1 month ago.

Today I found that channel 4 voltage readings would fluctuate erratically even when the voltage being measured was stable.
I tried performing the Zero calibration, and trying different probes. Even withChannel 4 input shorted to the ground terminal, within 10 to 15 minutes of performing calibration the voltage will start fluctuating.
The attached images were taken immediately after calibrating all 4 channels and then 15 minutes later, the 4 probe inputs were shorted to the ground the entire time scope was running.
Can you suggest anything I can try to rectify this problem?

Thank You
Regards,
Dave

Bauldy

Hi Amy,
Thank you for your response,

I tried warming up oscilloscope for 20 mins then calibrating as you suggested, this did not have much effect on how channel 4 behaved.
If I leave oscilloscope powered on for between 1 to 1.5 hours the bad fluctuations stop happening but the zero volts line will still keep on drifting above and below where it was after calibrating.

Regards,
Dave