EEVblog Electronics Community Forum
Products => Thermal Imaging => Topic started by: Stonecoldheather on December 13, 2020, 07:48:28 am
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Hello, I recently purchased a for parts Scott Eagle Six it arrived yesterday afternoon and I’ve spent all night Troubleshooting since. I’ve found a ton of useful information thanks to this website for an earlier project, and I’m hoping now that I’ve got a new question of my own maybe y’all can help out.
So I’ve gone ahead and bypassed everything but the core from the Scott Eagle, no point using the lcd or battery compartment if I can have a four-wire connection straight to the core I figure. The module faults the same way regardless of whether it’s connected to the rest of the camera so far it seems.
The symptoms are: (EDIT: I believe the MOSFET just above the caps is shot, there is continuity across all 8 pins and no diode voltage drop from drain to source)
- When powered up from variable power supply with current limit set to 1A, the current limit is hit at ~2V.
- If I power it as above and check it with another thermal camera, I can see that there is a hotspot which appears to be made up of three large unmarked SMD capacitors. The rest of the board remains unchanged. No signs of life from the core.
- If I connect ground to ground and then bypass the suspect caps by applying 7V at the positive end of the top capacitor it behaves the same.
- If I bypass the capacitors and apply 7V to a capacitor marked C 22 (marked yellow in attachment), just after the suspected failed caps and maybe some other components, the shutter spins up and the core begins to draw ~2A for maybe one or two seconds than settles down to .5A. All seems well but still no video output (maybe I’ve applied power past the video circuitry?).
So far that’s where I’m at. I’m not sure how to go about identifying the capacitors (C9,C10,C11), I’ll include some images of them at the bottom (red arrows in attachment).
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A 1A supply limit is not going to work as you observe a 2A turn on draw.
Typically this era of core is 8W to start and 5W when running, due to the peltier stabiliser.
Those capacitors look more like high voltage or ESD ones to me
Bill
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C9, C10, C11 are tantalum capacitors as well. See https://www.vishay.com/capacitors/list/product-40001/ (https://www.vishay.com/capacitors/list/product-40001/)
Unfortunately I don't know anything about this core.