hello again - had some time recently to continue working on this. Haven't been able to get it to work - so far it seems the power isn't turning on properly.
I did the following modifications:
1. link P2 pin7 to E2 pin 6
2. link E2 pin1 to E2 pin4
3. remove E2 pin 2
Here's a photo. Pin is removed from E2 on other side of board.
IMG_2205.jpg
I think the SMPS is going into ssurge overprotection mode when I switch on the unit. This is evident from periodic bright/dim flickering in the power LED, phantom 48v LED, and LED on the SMPS, all of which are completely synchronised.
I've tried 3 configs for powering on the unit. my motivation was to reduce the load on the PSU, seeing if i could eliminate the SMPS startup error.
1. unplug input module and eq module. When I do this, I think it works properly mode - LEDs are constant, suggesting no surge overpotection mode.
2. plug in input module only. When I do this, it always starts in surge overprotection mode. Sometimes, if i switch it on/off very quickly, i'm able to get it out of protection mode- LEDs become constant, and you can smell some slight fumes from the board, suggesting some heat is evolving from components. doesn't smell like burning. I have two input modules, and tried each othem separately. identical behaviour for both
3. plug in input and EQ module together. this always results in overprotection mode - periodic flicking on/off.
can i check the following regarding parts etc. I didn't order the full kit so some of the parts may be incorrect.
1. I am using PC817 opto cell for U2. Is this part adequate? Photo included IMG_2211.jpg
2. I've substituted c5 22uf for 47uf, didn't have any 22uf. Photo included
3. The board is populated with 1uf monolythic caps, eg for C6,C7 on the gain amp. This is different from some other kits like BA which use 0.1uf. Can I confirm that these are meant to be 1uf, NOT 0.1uf?
4. I just noticed that C25 is wrong on my board. I installed 10uf NP - should be 100uf. However, it looks like this is open circuit - connects to VU meter B pin which is disconnected on my board at the moment. So shouldn't affect anything (I think).
thanks a million - will send you extra photos in case it will help to check.
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