Cannot adjust TP1 to 5V : stays around -0.2V [SOLVED]

Hi!

I'm starting a new post here, as posting (as I did) in a topic marked as "Solved" may not be the brightest idea...

I cannot adjust TP1 as TM2 doesn't change the voltage between TM1 and Ground (it is around -0.2v... Very weird)

I do have a working screen displaying info (like "adjust TM2...").

I've checked every IC orientation and they are all correct.

I've checked +5V on every IC in the sequencer section, and all the square marked pins have +5V, so we're good regarding power I guess.

If I try to init EEPROM, it seems to work (including the info on the display), but after init, I have <Start> (flashing), <Stop/cont> (solid lit) and the first <Scale> LED (solid lit), but <Play> (under pattern) isn't flasing, as well as <C1>... And of course, no sound, just an unpleasant buzz sound (getting stronger after 2 secs when the Nava is powered on).

I've looked for parts that could be heating, but every part on the Nava seems to be at a cool and safe temperature...

I've checked every connection around IC110A (which has +15V and -15V as it should on pins 4 and 11), and everything is good : to TM2, to TP1, to R695, R696 and R697 (and then to ICs111 and 114 pins 3), to IC118...

And also something really weird : all switches light up when pressed except step switches (1 to 16), pattern switches and beyond on the right (including the <Enter> switch)... But if I get my finger close from IC106 (74HC595) on the switches and pots side of the board, BUT without touching the pins, all those LEDs light up ! I've switched the 74HC595 with another one on the board, but the issue remains the same... Very strange !

Thanks in advance for your help!

Sequencer issues really can be hard work to fault find so first I would go over the basics. Check for parts orientation, correct parts, dry/bad solders and shorts/splashes. Become familiar with the schem and use the top/bottom lay to check continuty - use a multimeter to check you haven't got a short between components you cant visually check so easy (electro caps, ic sockets). Double check your wiring. Go slowly and be maticulous

Thanks serum114 !
I already checked ICs orientation and +5V supply, and all is correct.
No solder shorts.
I've checked all connections around TP1 / IC110, and all is correct too, including voltage supplies (+5V, +15V, -15V).
Now I'm going to check the CPU --> Shift registers connections...
I'll post when it is done!
Cheers

OK... Sometimes, you're just so focused on very subtle things that you just can't see the obvious...
Pin 9 of IC107 wasn't properly inserted in its socket.

So now, I've been able to adjust TP1 to 5V.

The LEDs seem to react as they should.

When I initialize the EEPROM, I get the normal LED steps routine (from 1 to 16 slowly, then from 1 to 16 quickly)

[flash=]BUT[/flash]

Still some big issues, with erratic behaviour in the sequencer. For instance, if I press step 2 LED, it starts the sequencer. I cannot stop it. And sometimes it loops the first few steps, and then play all the 16 steps. Also, sometimes the 1st Pattern switch blinks rapidly. All this in a completely random way...

I'm going to move forward with my path / IC testing, but if you guys have a "usual suspect" in mind, feel free to tell!

Cheers

[EDIT] I've checked every connection of the shift registers (ICs 102, 104, 100, 108, 105, 74HC165), and everything is correct (to the switches, to the CPU, to ground, to +5V...)

Check in the config menu that you are in master clk and not slave. I've had a couple of Navas that after flashing would set the bpm to max, clk to slave and have strange led behaviour. I haven't experienced exactly the faults you mention but its worth a look. For me sequencer issues have always been hard to find.

Thanks again serum114!

I've checked, and I'm in Master Clock...

Also, I've switched all the Shift Registers for switches (74HC165) and for LED's (74HC595), with no luck...

What I have now is a kinda working Nava (all sounds working, except Clap and Ride, I'll move to that later...)... But I have to keep body contact with the Nava Ground for the sequencer not to turn crazy (and sometimes, even, I have to get my hands close to the Start switch because it went crazy despite the grounding... But if I get my hand close to the Start switch without me being connected to Ground, then it goes nuts (pattern play starts without me actually pressing the start switch, etc.)

If someone has some idea about what could interact with the Nava sequencer when you just get your hand close to the PCB but without actually touching it, I'm very much interested...

Cheers

[EDIT] I forgot to mention that I have a V1.01a board, and first I soldered C517, 518 and 519, but then I removed them, and the issue is still the same...

[EDIT2] Sound issues with HandClap and Ride are resolved (My grandma told me "boy, you gotta solder alll those IC pins or it won't work as it's supposed to"...

)
Man, it sounds good! I've runned it through a Sound Skulptor 5.12 preamp, with the right amount of gain saturation, and it is just beautiful!

BUT...

the problem with the sequencer is still there. I've noticed that when it's starting to bug (pattern resetting faster and faster until only the first step is played at, let's say, 300BPM...), it is solved if I press <Start> again (for a few dozens of seconds, until it starts resetting again). Maybe this rings a bell?

Here is a video to show what happens :

https://youtu.be/QuAm8poYtS4

Probably a long shot but could be a bad start switch as it keeps retriggering from the start of the pattern.

Unfortunately not, switch is OK...

Anyone's got other ideas?
I've checked the <Start> switch and re-checked the pull-up resistance, and everything seems fine. The only thing is that resistance of the <Start> switch in-circuit is around 1.3Kohm, whereas the other switches (like the sequencer steps for instance) are around 1.7Kohm...

[Solved] one solder joint on R639 (pull-up resistors for the Stop switch) bad. It tested ok before, but when one moved the resistor, contact with ground was on and off...
Thanks to Vincent, who's been of a great help, as always!