Spin Semiconductor Forum Index Spin Semiconductor
Support forum
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Troubleshooting a semi-working board

 
Post new topic   Reply to topic    Spin Semiconductor Forum Index -> FV-1 hardware questions
View previous topic :: View next topic  
Author Message
the_frey



Joined: 04 Jun 2016
Posts: 13

PostPosted: Mon May 08, 2017 2:28 am    Post subject: Troubleshooting a semi-working board Reply with quote

I've already implemented a board using the FV1, but it was super hard to solder in a logical order, so I redrew it. Just finished putting together the revision and I have a weird issue - I get audio through (both dry and wet - I've got a mix pot) but the signal keeps flashing out to a kind of static noise, at which point the clip LED lights. The static noise manifests sort of like the patch you're currently using from the EEPROM - i.e. on a pitch shifter, it has a differnt quality to a reverb patch, etc, which makes me think that there is a clean path from FV1 output to the output jack.

The weird thing is that if I push against the FV1 with my thumb, the signal resolves and the glitching over to the static either disappears or becomes much more infrequent.

That sort of suggests to me it's the opposite of a ground as it's not them touching the case or something like that.

I've checked the continuity of the pins on the FV1 and there are no shorts. The connections look okay with a magnifying glass, but maybe there are some dodgy connections, it's possible. I've checked the voltages and they seem in-line with the previous revision of the board, which I know works fine.

Could it be that I need to reflow the connections on the FV1? Maybe it's intermittent?

Is there anything else I should try?
Back to top
View user's profile Send private message
frank



Joined: 19 Oct 2005
Posts: 972

PostPosted: Mon May 08, 2017 7:34 am    Post subject: Reply with quote

Indicates an issue with the soldering of the FV-1, reflow the pins and make sure to clean any flux residue from the board.
_________________
Frank Thomson
Experimental Noize
Back to top
View user's profile Send private message Visit poster's website
the_frey



Joined: 04 Jun 2016
Posts: 13

PostPosted: Mon May 08, 2017 8:27 am    Post subject: Reply with quote

Ah okay, at least that validates my suspicion. I'll give it a clean to make sure flux isn't the issue too, and report back. Thanks!
Back to top
View user's profile Send private message
the_frey



Joined: 04 Jun 2016
Posts: 13

PostPosted: Mon May 08, 2017 11:38 pm    Post subject: Reply with quote

Reflowed all the pins and added a bit more solder and it sprang to life. Thanks again!
Back to top
View user's profile Send private message
the_frey



Joined: 04 Jun 2016
Posts: 13

PostPosted: Tue May 09, 2017 2:14 am    Post subject: Reply with quote

One last thing - I'm finding that PROG 4 is running my program from PROG 6 - I take it the only explanation for this is that I've got the wrong voltage being delivered to the pins right?

I've got a 1p8t switch and some diodes in place in a similar way to some of the implementations I've seen on here, and it worked previously. I'll re-check the diodes to see if any are duff, but I think they are fine, and they're definitely the correct orientation, so it does make me wonder what I've done wrong, heh.

Maybe it's just a solder bridge, the diodes are placed pretty close to one another on the PCB.

Reprogrammed a fresh EEPROM and it definitely seems like it's a hardware thing as switching it out to the other pedal the PROG 4 patch behaves as expected.
Back to top
View user's profile Send private message
frank



Joined: 19 Oct 2005
Posts: 972

PostPosted: Tue May 09, 2017 7:50 am    Post subject: Reply with quote

Check the voltage levels at the S pins to see if they are getting the proper level, if they are not then back track from the pin to see where the issue is. I would guess that S1 is not seeing the proper level when selecting program 6 and that is why it is running program 4 instead.
_________________
Frank Thomson
Experimental Noize
Back to top
View user's profile Send private message Visit poster's website
the_frey



Joined: 04 Jun 2016
Posts: 13

PostPosted: Wed May 10, 2017 1:39 am    Post subject: Reply with quote

Yeah S1 and S2 are both getting the same voltage for each, after checking again with the DMM. Must have misread it the first time. I've checked the schematic, diodes (on this board) and traces (on a fresh board), so it looks like I'll have to do a bit of digging to work out why there's a connection.

DMM says there's no continuity between S1 and S2 so it's not a solder bridge (and the other positions wouldn't work in that case I guess). Looks like the PROG 4 should not give a path to ground for S1 but it does, meaning it's the same on both pins as PROG 6. Weird!
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Spin Semiconductor Forum Index -> FV-1 hardware questions All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group