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Old 10-03-2018, 02:55 AM
luka's Avatar
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luka is offline
Join Date: Apr 2007
Location: Perth, Australia
Posts: 1,126
1. The back of the sensor is not grounded. The multimeter shows infinite resistance to ground and no voltage when the camera is on but this is only half of the story.

2. If the back of the sensor is grounded (via an electrically conductive thermal paste (Arctic Silver 5) to a grounded cold finger) the camera does not start. Considering that the USB does not even register on the computer, some voltage (3.3V?) must be pulled down.
In other words, if the back of the sensor is grounded bad things happen. Luckily the camera survived.

3. If a non-electrically conductive thermal paste is used the cold finger can be grounded and the camera works but the stripes are visible. I did not notice much change in the stripes if the cold finger is left floating.

4. The best case scenario... a floating cold finger electrically connected to the back of the sensor via electrically conductive paste.
The horizontal stripes are visible but only because I know what to look for. Or maybe I am imagining that they are there. However, they are quite visible in a stacked master bias file.

We may have to give up trying to PWM the TEC during the frame reads.

By the way, unlike here the grounding of the cold finger in a modified Canon 450D worked just fine and solved the noise problems.
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