Products > Test Equipment
TC1 lcr-meter transistor-tester fix
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indman:

--- Quote from: distefanom on April 19, 2022, 07:20:20 pm ---It still won't work and the micro shows what's in the attached photo-

--- End quote ---
Once again I repeat to you, if you did not understand me before - your clone has a hardware problem and no other firmware will fix it! Use a multimeter to check the resistance of all measuring ports of the processor relative to + 5V and GND.
LesioQ:
My tester TC-1 M-Tester died after a dozen of tests done (original factory graphical firmware).
The first problem I noticed was erratical behaviour - sometimes it booted OK but failed to test, sometimes it was hung-up on logo screen.
Sometimes the main screen display had pixel errors (image distorted).

Upon some testing I noticed it bahaves better if 5V supply is lowered somewhat. I ended up adding a Si diode right after (U3) 5V stabilizer with caps. Now Vcc is 4.2V.

It may be that communication with a LCD working on 3.3 Volt supply was causing problems.
Now it's testing OK, but fails to complete a Self-test - hangs at 7-16%.

Maybe someone can elaborate on that.
madires:
The tester needs 5V to run properly. Possibly a power supply issue, e.g. a broken MLCC. Do you have a scope to check the output of the boost converter?
LesioQ:
Sure I do. I was searching for some fluctuations on Vcc 5V, but it looks OK. HV is 39V, (after C13 & C14 replacement).
Vraw (5V stab. input) is about 9V.
madires:
A dodgy display (ST7735)?
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