Can't pass loopback test

[gloom15]

There is MS2 V3.0 Board, self assembled 4 years ago. Worked fine on my rx7, 4 month ago it was installed on my friends 4agte levin, we started car, begin tuning, but stop it due to bad turbo. About a week ago my friend changed turbo and tried to start car but failed, engine doesn't fire at all. I took my laptop and tried to connect to MS via bluetooth (there was a bluetooth module soldered in MS), but tunerstudio doesn't see MS. I took MS home, soldered out bluetooth module, installed MAX232 on it's place, but still can't connect. So I tried to measure voltage on MAX232 and on processor socket and get strange voltage:
processor socket:
PIN1 - 4,77V
PIN12 - 3,24V
PIN13 - 3,54V
PIN15 - 4,77V
PIN16 - 11,45V
PIN20 - 4,77V
PIN21- 4,77V
PIN22 - 4,77V
PIN24 - 4,77V
PIN27 - 2V
PIN31 - 4,77V

On 5V regulator voltage is 5.04V

On MAX232:
PIN1 - 4,77V
PIN2 - 3,88V
PIN3 - 4,37V
PIN4 - 3,85V
PIN5 - 2,1V
PIN6 - 2,3V
PIN7 - 3V
PIN8 - 2,6V
PIN9 - 2,5V
PIN10 - 3,25V
PIN11 - 3,25V
PIN12 - 3,5V
PIN13 - 3,37V
PIN14 - 3,07V
PIN15 - GND
PIN16 - 4,77V

5V regulator was very hot during this test, about 65 degrees C.

I tried to pass loopback test, failed.

I have another V3.0 board, but with MS3 duaghterboard, i measured voltage - voltage on pin1,20,31 is equal to voltage on 5v regulator, and it's cold, room temperature. On pin 12-13 there are 5V-0V.

Tried to solve problem using Troubleshooting guide, nothing helped.

[gloom15]

Tried to solve problem, unsoldered max232, installed back bluetooth module - it passed loopback test. Tried to connect in Tunerstudio, it can't find MS, in miniterminal ECU answers "a>." when I send anything. When I tried to load firmware, I've got message on picture, but ECU not in boot-jumper mode. When I try to continue, there is error - unable to open com6. When ECU in boot-jumper mode, ms2loader can't find anything...

[Matt Cramer]

Is the regulator still getting hot, or is that fixed?

[gloom15]

fixed, voltage stable 5.03V on processor socket

[gloom15]

Tried to fix it, got new results...
I was able to download standart B&G code, loaded succesfully, but seems that CPU stuck in bootload mode, but bootload jumper is off.
When I tried to load different versions of msextra code, i've got different errors.
And when I triyng to read ms signature, I always get "a"...

[gloom15]

Problem solved, motherboard damaged, CPU is OK. I've soldered board with 5v regulator, MAX232, installed daughterboard on this board and downloaded 3.40 ms2 extra firmware to daughterboard, launched Tunerstudio and it detected MS2 extra 3.40 on com3. So I need another motherboard...