Hantek DSO5072P oscilloscope channel 1 drift

[matt6ft9]

A week old DSO5000P Series (from Hantek) oscilloscope seems to have a channel 1 offset based on the heating inside the oscilloscope.  (The scope is in a climate-controlled office) 
The drift occurs if no probes are attached, if a grounded probe is attached, etc.  The drift occurs only on the 5V and 10V per division setting.  (A relay inside the scope can be heard clicking when going from 2V/division to the 5V/division setting)  When powered on, the offset is mean value of -1.8V, by the time it heats up, the offset is then zero.  (the offset has been as low as -2.2V)

The firmware is “3.40.0(180120.0)”, which seems to be the latest on the web site.  The self calibration under “utility” -> “self calibration” has been run many times.
Channel 2 seems to work great, no offset/heat issues.  The fan in the scope is operational

Has anyone else had this problem with a self-heating offset on this scope?   
If there is a simple fix, I would like to try it.  (or if it is a user error issue) Otherwise, I will send the scope back and see if the next one has the same issue.
Matt Meerian

[matt6ft9]

Update:
The channel 1 schematic/iinfo was found here: 

https://www.eevblog.com/forum/repair/hantek-dso4072c-oscilloscope-both-channels-bad/

By releasing small amounts of freeze spray, it looks like the AD8370 (750MHz op-amp) is source of the problem.  In single quantities, the opamp is a $10.74 part on Digikey.  During normal operation, both the AD8370’s on channel 1 and channel 2 operate at about 56C.  (a thermocouple was used to find the temp) 

‘time to send it back.
Matt