1977 Blackjack and Calculator Diagnosis

I got a Unisonic 21 untested and it turned out to need some work. Time to figure out what's wrong. This is a fairly anticlimactic video. It ended up "working" in the end but I didn't really do anything. I did notice it did actually very faintly turn on in the beginning, I still don't know why it got brighter over time. Yes I could buy the capacitors, but it doesn't make sense to place an order for just this device. Although I may do that in the future with an online order if I piggy back it onto something else. About the back filming surface, after a test video I decided to record a complete video using the underside of my ESD mat. Here is the test video:    • mattest   The blue reflects a lot of light onto the subject and into the camera during macro shots. A darker mat would give a noticeably better image quality. But the black is too dark. It didn't work well for this video. I will be going back to the blue side until I get something else that works better. The following product link(s) are affiliated and I may be compensated if your purchase something using them: If you want to get one of these and support the channel here are some links: eBay: https://ebay.to/2S7vVTa Playlists of more stuff like this: Calculators:    • Calculators   Electrical Engineering:    • Electrical Engineering   Repairs:    • Repair   1970s:    • 1970s   Other Links Youtube:    / akbkuku   Github: https://github.com/AkBKukU Thingiverse: https://www.thingiverse.com/AkBKukU Patreon:   / akbkuku   Discord:   / discord