Cambridge Audio Azur 651A , bricked I think !!

[guizmo1967]

Hello,

*** Excuse my writing, English is not my first language ***

I had a perfectly working amplifier but ….

I noticed there is a PIC16F882 that control this amplifier. Since I'm familiar with those PIC microcontrollers, I made a lot of program in C for different projects throughout
the years using those microcontrollers, I just wanted to see if I could just read this pic for keeping a backup of the firmware.

The pic got detected fine with my programmer, but It was reading all zeros, so I'm pretty sure it is code protected. After trying a few readings, now it is corrupted (bricked) !!!

Just to let you know, I did not accidently click the program button !!

When turned on with the switch at the back, it is supposed to go through all the led one after the other and stay in standby mode, until you pressed the power switch.

Now all the led are on and the power switch in the front does not work …

I tried finding a firmware on the internet, but no luck !!

[guizmo1967]

UPDATE !

I contacted Cambridge Audio support and they could not provide me the firmware for my amp neither their US service partner PanurgyOEM.

So, since I can program a PIC microcontroller easily , I'm not an expert but not a newbie neither, I'm going to create the firmware myself !!

When the amp was working, after the back switch was flipped, it did like a self test of all the led. A sequence from left to right, right to left, all off and power led dimmed. That part for me is easy to do !!

Press the power button, power led full brightness, I could hear a relay clicking, last speaker state and input led lighted, amp fully on.

For now I'm not going to program the protection part, like PIC Short, PIC DC, PIC Clip/VI, PIC Temp and neither the IR In, later.

Clock and Data are both for U2 (Front panel PCB) and U5 (Input PCB), LED strobe is for latching U2 and STROBE for latching U5.

Stby Tact = power button
Standby LED = power led full brightness
HP detect = Headphone detect
PO/HP mute = not sure, but I think when you plugged a headphone, it's supposed to cut power to both speakers ??
Standby relay = this one gets me confused. I tried to follow where it's going but could not !!!!


If someone is kind enough to look at U7 on the preamp PCB schematic and help me make like a flow chart after I pressed the power button, it would be appreciated. You can easily find the service manual online.