Electro Harmonix EHX POG v1 - Always on always bypassed problem
- Thread starter Astuck
- Start date
Help Support GroupDIY Audio Forum:
Following the Reset lines from U3 and U7, both are going to the main CPU : Philipps P87C52X2BA
pins 14 - 15 :
Pin 14=RESET DSP == 3.3Vdc ----------> U7 (DSP56364) pin29 == 3.3Vdc
Pin15=RESER CODEC == 0.02Vdc ----> U3 (AK4552) pin13 == 0.02Vdc
There is no capacitor nor resistor on the Reset lines, just through-holes paths from a side to another.
Reset lines are OK with a nice 0.05 ohm on both.
pins 14 - 15 :
Pin 14=RESET DSP == 3.3Vdc ----------> U7 (DSP56364) pin29 == 3.3Vdc
Pin15=RESER CODEC == 0.02Vdc ----> U3 (AK4552) pin13 == 0.02Vdc
There is no capacitor nor resistor on the Reset lines, just through-holes paths from a side to another.
Reset lines are OK with a nice 0.05 ohm on both.
Attachments
So today my solution is to bring back +3.3Vdc to the AD/DA converter Reset pin13.
As you can see on the picture, the red wire is picking +3.3Vdc on the closest point (+ of cap C30)
connected to U3 pin13 via the square pad from omit R36.
AD/DA converter is back from the brick mode. Intensive tests to come for stability...
Questions for the Digital Gurus : ____ ____
-Program from uController U14 sets the pins 14(INT0/P3.2) and 15(INT1/P3.3)
to a high state (+3.3v) in a sequential order. My fix gets pin15 inoperable and AK4552 pin13 is
permanently in high state as soon as you power this springbox.
What could be problematic with AK4552 being out of the sequentialy timed start-up ?
-What could be the true origin of the problem ? Pin15 could be dead, no more 3.3v for him ?
Thanks, cheers
As you can see on the picture, the red wire is picking +3.3Vdc on the closest point (+ of cap C30)
connected to U3 pin13 via the square pad from omit R36.
AD/DA converter is back from the brick mode. Intensive tests to come for stability...
Questions for the Digital Gurus : ____ ____
-Program from uController U14 sets the pins 14(INT0/P3.2) and 15(INT1/P3.3)
to a high state (+3.3v) in a sequential order. My fix gets pin15 inoperable and AK4552 pin13 is
permanently in high state as soon as you power this springbox.
What could be problematic with AK4552 being out of the sequentialy timed start-up ?
-What could be the true origin of the problem ? Pin15 could be dead, no more 3.3v for him ?
Thanks, cheers
