sequencer troubles please help ((SOLVED))

[CountRockula]

Ok I'm just about stumped on this. I just completed my kit that I bought from Technology Transplant. The analog section seems to all be working OK at this point. The only thing the sequencer part seems to be doing correctly is playing in random mode. Also the tempo knob works and and cooresponding LED flash. I can can sort of program a pattern whilst in pattern mode but the black keys do not register and when I hit start there is no sound. I'm thinking the envelope is OK because I can hear it play in random mode. When I run the pattern mode sequence the leds skip a few steps here and there Keyboard mode does nothing at all, no lights no nothing. I have checked and my soldering over and over. All resisitors in the digital section seem to be correct and soldered nicely. Also J4 is putting out 5.33 and 11.88v

Any help you guys can provide would be much appreciated.

[Altitude]

wow, another f'd up TT x0xb0x that we are expected to support. I'm shocked.

Check IC16,17,18 for obvious problems. Also, can you play it via midi?

[CountRockula]

After reading this forum for over ten hours straight I think this is the first time I've seen someone get flamed, and it's me. Just not my day today I guess. I'm seeing it recieve midi info but not hearing the notes. It's almost like the Microcontoller isn't sending a gate signal? This strange as I hear it just fine on random. Nothing obvious on ic16, 17, 18 I have swapped them back and forth with no change in behavior.

[Brassteacher]

After reading this forum for over ten hours straight I think this is the first time I've seen someone get flamed, and it's me. Just not my day today I guess.

It's not you at all, it's just that the source of your kit tends to be a bit "hit-or-miss" on quality. I can't speak for Altitude, but I think more than a couple guys around here will see the initials "TT" and think, "Well, here we go again...". Anyhow, his suggestion is definitely the place to start. ESPECIALLY check IC17, that's the one that handles the sharps and flats. On each one of the IC's that Altitude mentioned, make sure there is 5V on pin 16, and 0V on pin 8.

[CountRockula]

Thanks for the kind words and thanks even more for the help! All three IC's have 0v on pin 8 and 5v on pin 16. Also I followed the trace from r146 to the MicroController. When I hear the notes playing in random mode the controller is definitely cycling voltages on that pin sending them to the envelope/gate. Any other modes it's 0 whether it's midi info or it's own pattern. I'm leaning towards bad Microcontoller but will not rule out any other possibilities like a short somewhere. By the way where can I order a new pre-programmed Microcontoller preferably in the US?

[guest]

its possible the function switch is bad
that fact that random mode works
means that the micro is mostly fine

and if it was just the switch shift registers
then midi mode would work
check dinsync if you have the gear to do so

are you sure your sending midi on the right channel
and slave something on the midi thru
just to make sure the data is getting to it

what do all the modes do
do any of them repeat

[CountRockula]

its possible the function switch is bad
that fact that random mode works
means that the micro is mostly fine

and if it was just the switch shift registers
then midi mode would work
check dinsync if you have the gear to do so

are you sure your sending midi on the right channel
and slave something on the midi thru
just to make sure the data is getting to it

what do all the modes do
do any of them repeat

Hey thanks for the reply. It seems to respond to midi and dinsync. The tempo light is syncing up with the tempo of my Future Retro sequencer and it speeds up and slows down when I make the change on the sequencer. The R/S button lights up solid when I start the midi or dinsync sequence The FR does midi and dinsync and they both seen to give the same result. Also the C note led flashes along with the beat and the #1 led is lit solid. Still no sound as the MC is not outputing a gate signal. Again it does output a gate when on random. Strange to say the least.

I'll try slaving another keyboard with it tomorrow but I imagine it should pass the data.

As for the mode knob. Yes it does seem to repeat some of the functions, for example random is played on random, user a, user c. When on Computer Control all the leds light up solid. Boot load seems dead. The Bank selector knob also acts funny. As you turn it the leds just sort of jump around and also skip most of the selections. For example while in Patter Mode it goes 1-2-8-9-8-9-8-9-1-2 as you turn it clock wise.

Again, I really appreciate the help. It's very generous of you guys to help out total strangers!

[Altitude]

Nothing personal, all my animosity is towards TT.

Follow guest's advice and cycle through all the modes to see if you can get it to play notes over midi, one of the modes should allow you to do so. If it is the 16 position switch, I would consider returning the unit for one that works correctly, they are a nightmare to replace and there is a good chance you could damage the board trying to fix it.

[guest]

it sounds like there is something wrong with the encoder
or both encoders

check d3 through d10 for proper orientation
and if you have a diode check function
make sure they measure .6v

then measure the resistance between the common pin
and the rest of the pins on the switch
as you rotate it
each pin should be open for half of the time

then check for shorts on the traces that go back to the micro
from the rotary switches

[Brassteacher]

Nothing personal, all my animosity is towards TT.

Follow guest's advice and cycle through all the modes to see if you can get it to play notes over midi, one of the modes should allow you to do so. If it is the 16 position switch, I would consider returning the unit for one that works correctly, they are a nightmare to replace and there is a good chance you could damage the board trying to fix it.

I helped a friend build a x0x kit that had been sourced through TT, and one of his encoders was basically dead on arrival. The encoders he packs in the kit are substitutes, they are NOT the ones made by Grayhill, which are of the highest quality. Anyway, said substitute encoder exhibited the same behavior you are describing. We ordered the Grayhill encoders to replace the ones in the TT kit. Also, Altitude is correct about board damage. I've been earning a living as a repair tech on high-end audio for years, and even I damaged that board getting the old encoder out, even with decent desoldering tools. The board that TT has made has VERY lightweight copper traces, and they don't adhere to the board well at all. His boards are fine, as long as you don't make a mistake. They cannot take the heat very long at all. If you try to desolder the encoder, here is what I suggest:

1. Take a very small pair of wire cutters and clip the encoder off the board, leaving a little of the pins in place, and try to not put any stress on the pins as you cut it.
2. Heat the pin from one side, and the second you see the solder melt from the other side, grab the pin with needle-nose pliers or tweezers and pull it out (from the side away from the soldering iron if I wasn't clear). Don't forcefully pull on the pin, just make sure the solder is hot enough that it pulls out easily.
3. Important: Do one pin at a time, and before anyone says "You have to do them one at a time, DUH!", by one at a time I mean do one pin, let the board cool off, then do the next.
4. Put a real Grayhill encoder in it's place. If you have to clean solder out of the holes still, use solder wick, not a vacuum pump.

Luckily for my friend, I've had to do trace repair on circuit boards before, and during the five minutes he was freaking out about the damage, I had the new encoder in and jumper wired or with repaired traces as necessary. In other words, if a trace DOES break or peel of the board, don't despair, it can still be made to work without too much trouble.

[CountRockula]

Wow this is great info guys. Knowing that there is another TT kit that had the same issues is really helpful and encouraging. I actually ordered the new encoders this morning from Digikey along with all the IC's, extra buttons + any other stuff that could be "iffy" in the digital section, just incase. Yeah I'm noticing this TT kit has a few low quality parts in it. I fought with the power suppy for a week. Found there to be a bad 5v regulator (7805) and a bad LM336Z in ic22. It's a bit frustrating as there are no electronics stores where I live in Alaska, so I have to order everything....and wait. If I find that the encoders are bad I was planning to cut them off by their legs and desolder them very, very carefully. I'm actually thinking I might cover everything with pastic wrap and them dremel them off with a very small cut off bit then vacume everthing up with a static free vacume. I'll see how the small snips work first though. I just want a really clean cut.

Guest, I'll check those voltages tonight when I get off work.


Man, thanks for everthing guys!

[Altitude]

for the encoders, just cutaway everything you can so you can get at the pins one at a time. Getting those out individually is not that big of deal, same goes for ICs.

[CountRockula]

it sounds like there is something wrong with the encoder
or both encoders

check d3 through d10 for proper orientation
and if you have a diode check function
make sure they measure .6v

then measure the resistance between the common pin
and the rest of the pins on the switch
as you rotate it
each pin should be open for half of the time

then check for shorts on the traces that go back to the micro
from the rotary switches

I just finished all suggested tests. Checked orientation and tested all listed diods at .6v. So they are all OK. Next I tested the resistance of each pin to common on both encoders. They tested 100% functional. I then tested the traces back to the MC, they all tested OK. Dang I was hoping it was as easy as replacing the encoders Looks like they are OK.

[phono]

i woudl say try reflashng the controller but since its a TT box this is not possible

[Altitude]

Check IC16,17,18. Those are the shift registers for all the tact switches. If there is a problem there, the buttons wont work