Originally Posted by nutthouse
For all with the eeprom error when power is removed from the AVR. I had the error that would go away with any version of firmware below 1.07. I must have downloaded 1.07 and 1.08 a dozen times but would always have the error after upgrading.
Searching the schematics you find Q9371 in the microprocessor schematic. This chip is the 64Kbit eeprom made by ISSI. It has been obsoleted by ISSI and I could not find it without a large minimum order from some online parts brokers. It costs .5o cents so it is a commodity type item and Digikey wanted a 20,000 piece order. I found a 100% compatible made by Microchip and orderd from Digikey .98 cents. Last night a car hit a power pole and the power went off so this spurred me into changing the chip ( I get mad everytime the power goes off).
OK, so after the last loss of power, I took a few hours today to do the same operation that you have done. I could only get my hands on 25LC640A easily, but seing that the Onkyo is powering these chips with 3,3V made me think it would be OK. And it was!
I have tried all kinds of trick to be without the eeprom error, but nothing worked until I changed the IC on my 905/1.08.
In my change, I decided to remove the ethernet modules, the FM radio, the Reon board the video input board and the back plate in order to get a good working area, as I did not feel confortable to change the part by only removing the reon board. Guess my eyes is not a good as yours! It felt like 100 screws, and the complete change over took more than two hours. But now I am so happy
Even though I am very experienced in electronics (been working with it for 25 years), I was quite nervous when powering up, because the 905 is not a very easy to service unit imo, so I think that I also would like to emphasize that anyone setting off to do this themselvs, need to be very careful and let it take some time.
Anyway, I just wanted to thank you all for the firmwares, the fight with Onkyo, and obvisously, the description of what IC to change!