LCR-T4 ESR Meter repair

LCR-T4 display blinks, shows testing battery and turns off. When pushing button 78L05 shows input 5.4V (R leg) and output 3.5V (L leg). ATmega328P 4 VCC, 18 AVCC and R273 show 3.5V. B – base, C – collector, E – emitter. PNP M6 (9015) transistor C is connected to 78L05 IN (R leg). M6 B 9V and E 9V in OFF state when 78L05 is not receiving power. When button is pressed M6 B 8.35V C 5.4V E 9V. When button pressed ATmega328P 11 PD7 should be GND and 10 PD6 should be +5V.

78L05 OUT > 1uF > 100n > R103 > R273 > 18 AVCC (4VCC, 6 VCC, 29 RESET +5V) > R222 > TL431 and TL432 are adjustable shunt voltage references with guaranteed temperature stability over the entire operating temperature range. The device temperature range is extended for the automotive version from -40 °C up to +125 °C. The output voltage can be set to any value between 2.5 and 36 V with two external resistors. The TL431 and TL432 operate with a wide current range from 1 to 100 mA with a typical dynamic impedance of 0.22 Ω.

Power problem on LCR-T4. Low and insufficient voltage. Avoid checking capacitors on PCB with probes without proper safety. ATmega328P is broken, because it’s very hot during firmware read and write. Read hex and eep only partly. Write do not verify. Need new chip.

ATmega328P U-KR

TXC g 8,00D1.66

78L05

TL431

CH341A MIOS [ (16 pin) MISO – 1 2 – +5V                  ] CH341A 5V

CH341A CLK   [ (17 pin) SCK    – 3 4 – MOSI (15 pin) ] CH341A MOSI

CH341A CS      [ (29 pin) RESET – 5 6 – GND               ] CH341A GND

AVRdudessPROG_ch341a – easiest way on Windows.

Someone recommended not to use BODLEVEL 0 – (FC). (FD) to avoid inaccuracy when measuring 100mF capacitors. Don’t know whether it’s true.

avrdude: safemode: lfuse reads as 62

avrdude: safemode: hfuse reads as D9

avrdude: safemode: efuse reads as 7

avrdude: safemode: Fuses OK (H:07, E:D9, L:62)

avrdude done.  Thank you.

DO EVERYTHING AT YOUR OWN RISK!

https://www.instructables.com/How-to-change-fuse-bits-of-AVR-Atmega328p-8bit-mic/

https://www.youtube.com/watch?v=6DZTMf5A0to - Прошивка тестера LCR-T4 программатором CH341A

https://www.youtube.com/watch?v=U7xRoebYJwg - Firmware of the lcr t4 tester with the CH 341 A programmer

https://www.youtube.com/watch?v=3AKtTnvaf-Q - Так вот почему LCR-T4 отключается.

https://www.youtube.com/watch?v=oP-m3NZuVXo - Транзистор тестер LCR-T4 загорается экран но ничего не показывает. Ремонт. Прошивка.

https://www.youtube.com/watch?v=DxhGD5-sd8A - Внутрисхемный ESR метр из транзистор тестера.

https://www.youtube.com/watch?v=Q7d4ddDMzCw - Ремонт ESR метра с Aliexpress. Нет питания при тестировании

https://www.youtube.com/watch?v=jHL565QFAdY - Ремонт транзистор тестера LCR-T4(T3)NoStripGrid после неразряженного конденсатора...

https://www.youtube.com/watch?v=llIOhNmTo7Y - Неисправный транзистор тестер и его восстановление

https://vrtp.ru/index.php?showtopic=25020&st=0 - Клоны тестера Markus Reschke и Karl-Heinz K, Китайские виды сборок, моддинг,прошивка

https://disk.yandex.ru/d/yW8xa5NJgUo5z – Clone Tester – firmwares

https://github.com/kholia/transistortester - Tweaked Markus' firmware for the 'Blue Button' LCR-T4 model from techtonics.in.

https://4pda.to/forum/index.php?showtopic=948444 - Транзистор Тестер с Али

https://www.elektroda.com/rtvforum/topic3372311.html - Change of the firmware of the LCR T4 M328 element tester from the elektroda.pl

https://www.elektroda.com/rtvforum/topic3354445-600.html - LCR-T4 electronics components tester ATMega328 - Test and Review

https://www.youtube.com/watch?v=1PjaDQ4obSM - Питание для китайского тестера транзисторов.

https://www.youtube.com/watch?v=PzW8x5RNb_E - 9 Volt Power Supply For LCR-T4 Tester. No More 9 Volt Battery ( Installation )

https://www.eddy.com.ua/archives/1058 - Переделка транзистортестера LCR-T4 на питание от лития (и корпус)

https://mysku.club/blog/china-stores/43702.html - Универсальный тестер LCR-T4 12864 LCD ESR SCR Meter - замена экрана

https://mysku.club/blog/aliexpress/97022.html - Восстановление транзистор тестера LCR-T7-H с платой T7-PLUS V0.1

https://www.youtube.com/watch?v=PqNFOxGs8LU - Транзистор тестер LCR T4 Обзор Тест Что он умеет чего не умеет Небольшая инструкция Как пользоваться

https://www.youtube.com/watch?v=Ud8LkukXjBU - Универсальный тестер GM328A. ПОЛНЫЙ обзор. Калибровка, тестирование, разбор принципиальной схемы.