Hand slipped busted something! :-(

[MMM]

Usually I put the ground through the hole on the heatsink of the chip on the I/O board, however in this case I tried several ground points including the left side of r144 which according to the schematic is a ground... No matter which ground, I got a consistent result.

OK. I'm only asking because there are actually different "grounds" (an analog and a digital one) that are tied together on the IOboard. If both J3 and J4 are connected they behave as one "big" ground; if either J3 or J4 are connected (but not both) they don't which can lead to strange things.

I have removed Q37 and as you said, the middle pad is measuring about 11.7v close enough I believe?... Again not going to take any further action till I hear your thoughts.

This looks as if (at least) Q37 is faulty. If you have a spare SC536 install it. If you don't have a spare you can use Q50 from the IOboard in the meantime (you'll not have any MIDI In functionality without Q50, though).

[maclean]

OK. I'm only asking because there are actually different "grounds" (an analog and a digital one) that are tied together on the IOboard. If both J3 and J4 are connected they behave as one "big" ground; if either J3 or J4 are connected (but not both) they don't which can lead to strange things.



This looks as if (at least) Q37 is faulty. If you have a spare SC536 install it. If you don't have a spare you can use Q50 from the IOboard in the meantime (you'll not have any MIDI In functionality without Q50, though).

Do you think I should be putting the black probe somewhere else? I must admit I'm not really sure but if you have advice on the best place to use I will certainly follow. I have not even put J3 together yet and have so far only got J4.

I checked how many SC536s I have left compared to how many I need to finish the kit and I have been sent one extra in my kit!! So I soldered the extra one in and measured the middle pin and am now getting 11.7v... That's gota be a step forward eh?!

[MMM]

Do you think I should be putting the black probe somewhere else? I must admit I'm not really sure but if you have advice on the best place to use I will certainly follow. I have not even put J3 together yet and have so far only got J4.

No, the heatsink hole (or in general the metal part) of the 7805 should be ok at this moment. You can always check if this is a "good" ground by measuring the voltages on J4.

I checked how many SC536s I have left compared to how many I need to finish the kit and I have been sent one extra in my kit!! So I soldered the extra one in and measured the middle pin and am now getting 11.7v... That's gota be a step forward eh?!

Definitely. However "a step forward" sounds to me as if something else is still not working? You're not getting any sound yet when applying the appr. 5.3v to the correct side of R146?

[maclean]

Hey I think I'm back on track!!! I didn't try anything as I didn't want to rush ahead without seeing what you said first!


Powered it up put the headphones on, touched the bottom of r146 with my 5.33v clip and Im getting what sounds like a 303 pluck!!!

I guess I can assume that nothing else is fried, The pots are all effecting the sound as I be;live they should!

I can't thank you enough for getting me to this point!!!!

[MMM]

Sounds like you're on the right track now!

Good luck with the rest of the build - and remember to doublecheck everything! And feel free to ask if any other question comes up.

[maclean]

Hey MMM I finished my xoxbox today... Put the cover on etc and with a large sigh of relief the sequencer section worked fine and had it spitting out acid all this morning....


Many thanks for helping me out when I needed it MMM.

Cheers

[SubStyler]

good job! both of you... maclean and MMM!

[MMM]

Hey MMM I finished my xoxbox today... Put the cover on etc and with a large sigh of relief the sequencer section worked fine and had it spitting out acid all this morning....

Very cool. I'm sure you'll have lots of fun with it.