Hello,
I have just build a new CORE (V3 from Mike), and when all the stuff is connected, the pots connected to AIN J1 and J2 have range values from -64 to 63. The pots connected to J3 are showing good range values (0 to 127).
I use an AIN module from SmashTV, everything seems to be well connected and soldered, where could I start to debug such a precise issue ?
Kind regards
Philippe
additionnal information : if I connect the unit to MIOS Studio, the range value are 1 to 126 I can’t reach 0 or 127 so the range differs from the one display on the LCD.
another thing I have noticed that about several cc events are happening when I switch on the unit during about 20 seconds even if I don’t touch to any pots, then arbitrarily one CC event happens, the channel concerned is not always the same, And finally when I turn the pot of a channel, sometimes other channels are giving CC events, and if I leave the pots the channel continue to give CC events during few seconds.
I just want to say that before building the Mike CORE V3 I have used a SmashTV CORE where Anolog input where perfectly working (unfortunatly not the digital inputs), so all the pots connections to AIN module and ground haven’t been touched.
Thanks in advance for your kind help.
Philippe
I’m not sure about the missing step in -64 to 63 or 0 to 126, but the spurious CC’s sound like a noise issue. Have you grounded all unused analog inputs on the AIN module? If you have and the issue persists, it’s possible that the wires you’re running to the pots are too long, cross something introducing interference, or both. The length of the wire might also be producing a small voltage drop, which *could* explain your missing steps as well.
just to clarify what I mean:
just to clarify what I mean:
yeah thanks a lot jbartee ! the schematic you point me was very precious to resolve the thing, I hadn’t connect the Vs pin of J5 to ground (that’s was the cause of the spurious events) and I did connect the wrong pins of J5 to the the AIN module (that explain why I had a range from -64 to 63)
no more missing steps all the analogic part is perfect now 
Not the same for the DIN module : after two build of the SmashTV core and 1 build of the Mike core, I have always voltage < 4V at the J9:SI pin when I use the SRIO_interconnection_testV2 (without the DIN module connected to the CORE).
It would be evil that I always fall in soldering something well that would result to the same issue isn’t it ? there is certainly something odd that should alert Törsten.
I’m very open to check what you want me to check to find the problem, I can also send the SmashTV CORE to someone for debugging.
nevertheless thanks a lot for your kind help jbartee !
Philippe
yeah thanks a lot jbartee ! the schematic you point me was very precious to resolve the thing, I hadn’t connect the Vs pin of J5 to ground (that’s was the cause of the spurious events) and I did connect the wrong pins of J5 to the the AIN module (that explain why I had a range from -64 to 63)
no more missing steps all the analogic part is perfect now
Not the same for the DIN module : after two build of the SmashTV core and 1 build of the Mike core, I have always voltage < 4V at the J9:SI pin when I use the SRIO_interconnection_testV2 (without the DIN module connected to the CORE).
It would be evil that I always fall in soldering something well that would result to the same issue isn’t it ? there is certainly something odd that should alert Törsten.
I’m very open to check what you want me to check to find the problem, I can also send the SmashTV CORE to someone for debugging.
nevertheless thanks a lot for your kind help jbartee !
Philippe
Glad the analog inputs are working properly!
as you can see from this schematic, J9:SI runs through R9, which should be a 10k pull up resistor. Unless there’s something wrong with your power rail further up stream (do you measure 5v at other points on the board?), I’d start by double checking your work around R9.
in fact with the 2 SmashTV’s CORE and the Mike’s CORE I’ve build I have the same issue describe in this post here : <___base_url___>/index.php?/topic/13748-pin-rdo-20-of-the-pic-18f452-at-4v/&do=embed
on the Mike’s CORE I have the 5V on the postion where Törsten advice to check here : http://www.ucapps.de/mbhp_core.html
I have 5v just before R9 and less than 4v after at RD1 of the PIC and J9:SI.
I’m not an electronicien as you can see, and I use a cheap analog multimeter (but it show me 5v where I should find it at others points).
by the way, the MIDIO128 doesn’t show events from my buttons when I press them so there is something odd somewhere.
Thanks again.
Philippe
in fact with the 2 SmashTV’s CORE and the Mike’s CORE I’ve build I have the same issue describe in this post here : <___base_url___>/index.php?/topic/13748-pin-rdo-20-of-the-pic-18f452-at-4v/&do=embed
on the Mike’s CORE I have the 5V on the postion where Törsten advice to check here : http://www.ucapps.de/mbhp_core.html
I have 5v just before R9 and less than 4v after at RD1 of the PIC and J9:SI.
I’m not an electronicien as you can see, and I use a cheap analog multimeter (but it show me 5v where I should find it at others points).
by the way, the MIDIO128 doesn’t show events from my buttons when I press them so there is something odd somewhere.
Thanks again.
Philippe
Okay. Just in the interest of being absolutely sure, do you get the same measurements at RD1 and J9:SI when the PIC is removed?
It sounds like you’ve already narrowed it down; If you measure 5 volts before R9 and less than 4 directly after, then the problem must lay with R9, either at the solder joints or somewhere along the traces. Check for cold joints, reheat or desolder as necessary.
Okay. Just in the interest of being absolutely sure, do you get the same measurements at RD1 and J9:SI when the PIC is removed?
I’ve just test it without the pic : I get the same measurements
It sounds like you’ve already narrowed it down; If you measure 5 volts before R9 and less than 4 directly after, then the problem must lay with R9, either at the solder joints or somewhere along the traces. Check for cold joints, reheat or desolder as necessary.
I have reheat, traces seams to be separated (by nude eye). Something I’m not sure, is it normal to find a short between J9:SI and VS of about 15 ohm ? (it is hard to mesure this more precisely with my cheap analog multimeter)
Thanks for your help jbartee
Philippe
Please give me some help, I’m desperate with this issue since 2005 
That sounds like a “short” to me, There should be a very high resistance between SI and VS, as it has a 10K pullup, there shouldalso be 10K ohm between SI and VD. If you remove the PIC, does it still read 15ohm between SI and VS? if so there is a short somewhere on the board.
Cheers
Phil
You must be right it is a short, I’ve the same measurements without the pic.
I’m damned with this CORE, I must admit that I’m not enough skilled to build such a unit : 3 builds 3 failed
Thanks a lot Phil
Philippe
perhaps my last chance : here is a macro pic of my CORE : http://migratis.net/core.jpg
can somebody point me to the potential fault part ?
Thanks in advance
Philippe
Looking at the picture, it is quite messy under J9. It is quite possible that the “mess” is causing a short. I would try cleaning the PCB with an old toothbrush and some alcohol based cleaning solution first.
There are some other joints that appear to have a bit too much solder on which could be causing a “bridge”.
A similar shot of the top of the PCB would also be useful (to make sure everything is in the right place!)
I don’t want to make you feel even worse but I have built Cores from both Mike and SmashTV and never had a problem so i’m sure it is something that can be fixed
Cheers
Phil
arf thanks Phil but I’ve just ruined the PCB by wanted to remove the to much solder on some joints, I will ask for Mike if he would be kind to mount it for me and I will pay the time by paypal.
Thanks again.
Philippe
When you say you have “ruined” the PCB. Do you mean that you have lifted a track (or 2)? This can usually be fixed with some link wire (or cut leads from other components). What type of soldering iron are you using? It may be too hot as you shouldn’t lift tracks unless you left the iron on the track for a long time.
What is wrong with the other 2 CORE PCB’s that you have failed to build? Do you still have them? It may be possible to fix one of those?
I really hate to give up on this sort of thing and I have repaired PCB’s before that others wanted to throw away because they had burnt out or lifted tracks. The result never looks particularly neat but if it works, so what
Although the picture wasn’t “that” clear, the soldering didn’t look too bad to me, other than the common mistake of too much solder on some joints. A good joint should look like this, slightly rounded but not a “ball” of solder:
Cheers
Phil
When you say you have “ruined” the PCB. Do you mean that you have lifted a track (or 2)?
yes I do and I have also connected tracks with solder and I’m unable to remove those bridges the solder is so thin than my solder pomp pomps nothing and when I scratch the bridges it lifts the tracks
it is quite a botch work
This can usually be fixed with some link wire (or cut leads from other components). What type of soldering iron are you using?
I use this one : http://www.lapanthera.hu/hu/doc/SOLOMON%20SR965.pdf . I don’t know if it is 25W or 40W because it was part of a cheap soldering kit with pliers, wire cutters, a pomp and 1mm solder all this for only 30€ in 2005.
What is wrong with the other 2 CORE PCB’s that you have failed to build? Do you still have them? It may be possible to fix one of those?
the first one (SmashTV pcb) is definitly dead, the voltage regulator is heating like hell and no more display and midi out/in.
the second one (SmashTV pcb)is always working well apart this J9:SI problem that shows less than 4V
Although the picture wasn’t “that” clear, the soldering didn’t look too bad to me, other than the common mistake of too much solder on some joints. A good joint should look like this, slightly rounded but not a “ball” of solder:
Yes I would very like to do such joint
perhaps I should acquire better soldering tools, can you advice me on a good soldering iron and solder for this type of build ?
Best and thanks for the time you spent to help me Phil.
ps: as I was afraid and I completely understand, Mike has no time to build the unit for his customers, so I will have to struggle myself…
Philippe
the first one (SmashTV pcb) is definitly dead, the voltage regulator is heating like hell and no more display and midi out/in.
May be you will find some short circuit between the 5 volts DC power rails, only.
You can make measurements without PIC, LCD. If OK , connect it’s again and compare results.
Regards, Janis
May be you will find some short circuit between the 5 volts DC power rails, only.
You can make measurements without PIC, LCD. If OK , connect it’s again and compare results.
Regards, Janis
Victory ! I did rescucitation of the dead PCB. as you suggest, I followed the 5V tracks and found solder that had overflow on the top side of the pcb but hidden by the body of a capacitor.
So now I have 3 CORE pcbs that shows the exactly same symptoms :
j9:SI at about 3,8V with and without the PIC, 5V is well measured upstream R9
J9:SI and VS with a resistance of about 20 Ohm (the Mike PCB as suggest Phil was messy around J9, but the SmashTV one’s are really not messy).
I don’t know why but I suspect that it is a reproductible error that I make, when I look to the SmashTV’s PCB I’m more confident on the fact that the problem is not an arbitrary short won’t you ? Does any arbitrary short leads to the same symptoms ?
Thanks !
Philippe
j9:SI at about 3,8V with and without the PIC, 5V is well measured upstream R9
J9:SI and VS with a resistance of about 20 Ohm (the Mike PCB as suggest Phil was messy around J9, but the SmashTV one’s are really not messy).
If the PIC isn’t installed, I really can’t see how you can possibly have a short on all 3 CORE boards unless as you say, you have made the same mistake on all of them!
Looking at the circuit diagram for the core, J9:SI connects directly to pin 20 of the PIC and has a pullup to 5v via a 10K resistor (R9). It should have no connection at all to Vs. Looking at the quick view of the layout on ucapps.de, J9:SI looks to be connected by a very fine track which runs between the other pins so if you haven’t been particularly careful with your soldering iron, it would be easy to accidently bridge some solder over the tracks.
Vs is the thick track that runs most of the way round the outside of the PCB so make sure that there is no solder bridge between J9:SI and it.
Thanks
Phil
