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TC1 lcr-meter transistor-tester fix

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mtcaus:
There is one more area you could check for your issue before you determine its ATmega.  Check your testing sockets for any possible "shorts". I once bought a ESR02 PRO and it's working "fine". However once in a while after testing a few components, I would get calibration screen or show pin 1(3) and pin 3(2), (random pins) shows a cell, resistor or capacitor just like yours, but there is none on the testing sockets. Upon close inspection, I saw a solder sticking out from 1 test socket to another.  They weren't touched each other, but enough to cause weird problems. I removed it and the problem solved. It's a manufacturing defect.

masster:
I didn't find any short between input pins.
Instead, I took another thermal image (see attached) and there is a hotspot on filter capacitor C7. Fingers crossed. By the way, what value have the filter capacitors? 10 uF and 0.1 uF ?
The output voltage of first step up converter is 6.67V (correct according to resistor divider (0.6 x (1+100k/10k)) but lower than 2 Volts over stabilized voltage of 5V.
The output voltage of the second step up converter is 22.6V, again correct.

TurboTom:
No, the hot spot is not C7. The optical overlay over the thermal image isn't accurate at these close distances, the hot component is the Atmel. Better disable optical overlay when working at close distaces and use common sense...  ;)

masster:
What optical overlay are you talking about? There is no such thing. The image on the left was taken with a regular phone camera. The image on the right came directly out of the FLIR device, and it is not in overlay mode.
I have cropped the left photo to look similar to the framing of the FLIR photo. Moreover, what common sense are you talking about? Condemning the ATMega chip by default? I'm looking for a short circuit on VCC bus. What is wrong with a capacitor being shorted? What do you know about the precision and resolution of the FLIR device I'm using? Nothing.

TurboTom:
Sorry I didn't mean to sound rude or to offend you. But if you look at the colour grading of the heat distribution, you can clearly see the "X" shape of the chip carrier inside the Atmel. And with "common sense", I mean, that at a maximum temperature of sixtysomething degrees, just use your finger for a quick check. I'm absolutely sure that in this case, it's the Atmel that's getting hot. And the thermal image surely looks as if there is a visual overlay. The thermal image itself is quite out of focus, so the sharp structures visible in there cannot be part of the thermogram. I hope this makes sense...

P.S. FYI, I attached a true in-focus close-up thermogram of my (old style) TC1 PCB after maybe three consecutive testing cycles. You can clearly see the metal chip carrier inside the AtMega's enclosure. But you can also see the (reflective metal) terminals that don't emit heat. Obviously, temperature difference of this intact unit is much lower than you found on yours. If you look carefully, you see two of the tiny SMD resistors get slightly "warmish" -- the high side of the zener voltage divider and the shunt of the voltage reference --  and that the copper tracks below the silkscreen dissipate some of this heat. Thermal camera is a "pimped" Flir E4 with an additional close-range ZnSe lens with a focal length of 75mm IIRC. Without this optics, close-range thermographs aren't possible with this entry-level thermal imager.

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