Addendum: When Bios eeprom chips are in-circuit grounded to GND on for instance the Write protect pin, any attempt to read and copy the Bios in-circuit will fail. No matter if the Vcc pin 8 wire on our test clip was cut and that board with Bios chip on it was power fed externally or not. Today that happened when I was trying to read and copy the 25VQ32 Bios in my Cabletech DVB-T2 receiver. It could never be read at all in-circuit with As-Programmer or Neo-Programmer and my CH341 Mini Programmer and had to be removed from its board before it finally could successfully be read and copied!

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Many thanks, I have saved this also and shall try as and when I get back to it.

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Many thanks, I have saved this also and shall try as and when I get back to it.

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Additional info: Reading bios or processor chips IN-CIRCUIT often fails simply because the Vcc that comes from your 6 or 10 pin ISP cable and goes to the attached board also drives all other parts simultaneous in your attached circuit. Which may cause databus conflicts or erratic behavior that blocks reading out your data correctly, which shows when you Verify the data in your computer buffer to the data still present in your bios chip or processor chip, when it fails to confirm they are identical!
This In-circuit problem when for instance using a mini programmer like the CH341 with its 8 pin wire clip easily is avoided by cutting the Vcc pin 8 wire on the clip. And then simply feed the board with the intended chip to read-out or program with its original power supply. This then always fixes the Verify failing issue and your read data is okay!

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Interesting read here how to program AVR chips with the CH341 mini programmer: https://ericdraken.com/avr-amtel-attiny-ch341a-isp-programmer/
There even is a CH341 to AVRdude patched version support (fullspeed and bitbang) for Windows WCH official driver and Linux (based on Alexey Sadkov patch and WinChipHead sources) here: https://github.com/maxxproff/avrdude-ch341
or this one here: https://github.com/Trel725/chavrprog

PS: on page 237 of the ATMEGA8535 datasheet it mentions this => The ATmega8535 provides six Lock bits which can be left unprogrammed (“1”) or can be programmed (“0”) to obtain the additional features listed in Table 97. The Lock bits can only be erased to “1” with the Chip Erase command.

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Many thanks, dear Mark!

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Since another complex work is on my table and I have to focus on that, right now I have no answer to your questions. The number printed on the programmer is USBASP V2.0 and the IC used has a name ATMEGABA AU 1423. On the cover there is a printed number : 6645-09 AVR Programmer for ATMEL Processors. Only this much I can provide for the time being. Many thanks for the time you are spending to help me out.

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As you know most of the TV repairs are above my experience level dear Parasuraman. I only shared the mentioned digital information on programmers and AVR processors because of your smart move in buying such an ATMEGA programmer. Sadly you didn't share any information about what interface program you used. AVRDUDESS is a GUI for AVRDUDE that works in Windows and is a good tool for programming Atmel microcontrollers. I guess your ATMega programmer was a cheaper 5 or 6 pin ISP or ICSP serial mode programmer? With those you are stuck if serial mode communication in the ATmega is blocked or the protection bit was set. You can reset all fuses in parallel programming mode re-use these processors but then also lose the program data in the ATMega chip. So I wonder if that firm will be able to read out or restore the pre-programmed firmware in that case when it is copy protected.

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