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PostPosted: Fri Jan 06, 2017 7:32 pm 
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Okay, we know it's not a chip problem. It shouldn't be a trace problem because you do have continuity to the other pin 8s. You can't see the trace in the bottom but we know it's there since you have a connection to the power rail.

We know there is a short somewhere because the battery is getting hot.

Let's think on this for a bit.

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 Post subject: Phase Royal: no effect
PostPosted: Fri Jan 06, 2017 7:36 pm 
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Food for thought - the most troubling build I ever had was a 2g BYOC phaser. I was convinced the fets were bad, replaced those, replaced ics, replaced the bjt, replaced all the lfo components, still bad. Finally like 18 months later I found it in a drawer. I reflowed every joint and tested it 3 times. 3rd time was a charm.

Now, whenever I have an issue I can't pinpoint, I make sure and reflow every single solder joint several times.

Every. Single. Joint. :wink:

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PostPosted: Sat Jan 07, 2017 11:45 am 
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I'm being a JAFO here, but stick with it. These guys are super smart and are tenacious when it comes to troubleshooting!


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PostPosted: Sun Jan 08, 2017 2:17 pm 
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Lately, I've been hearing and reading in many places that a sure sign of insanity is doing the same thing over and over and expecting different results. I may fit into that category.

After reflowing everything twice more (some areas more than that), my results haven't changed a bit.
IC4 voltages are stuck: pin1: 1.55, pin2: 1.53, pin3: 3.87, pin4: 0, pin5: 3.87, pin6: 2.70, pin7: 1.52, pin8: 0.86.

So I got to thinking about pin 8 being the power supply for all the IC's, and started checking the pin 8 voltages on all the IC's.
Lo and behold, IC4 was the only one that wasn't 9.15V at pin 8.
So I checked continuity between IC4 pin 8 and all the other IC pin 8's: no continuity. IC4 is not getting any power.

I then went into a desolder/solder/reflow routine on IC4 pin8. Did that at least 6 times. I'm sure that's one of the areas on the board that I screwed up during the initial build. There's no sign of trace around that hole, so wherever pin 8's supposed to be going, it's not getting there.

And, just for giggles (except I'm a long way from giggling), I decided to put a jumper wire between IC3 and IC4, jamming it into the socket beside the chip's pin 8 in both sockets.
Powered up again and now IC4 voltages are: pin1: 3.95, pin2: 3.94, pin3: 3.94, pin4: 0, pin5: 3.94, pin6: 3.94, pin7: 3.92, pin8: 9.15.

I'm afraid to even guess what this means. Have I blundered into a solution? Or is this all irrelevant?


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PostPosted: Mon Jan 09, 2017 10:28 am 
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Progress!

Decided this morning to see if this thing now passes a phased signal, and it does.
Very weak sounding, though. Not weak in volume, that's fine. Just very, very little effect.
The trim pot does make a difference, but its rotation goes from dry to weak effect to dry.
None of the pots seem to make much difference in the sound.

IF my jumper is indeed the fix for my IC4 problem, I will solder it in place on the bottom of the board. Is there a better place to pick up the 9V I need at IC4 pin 8 rather than at IC3 pin 8? I just put my temporary jumper there because it was close to IC4.


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PostPosted: Mon Jan 09, 2017 12:34 pm 
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lk155 wrote:
Decided this morning to see if this thing now passes a phased signal, and it does.
Very weak sounding, though. Not weak in volume, that's fine. Just very, very little effect.
The trim pot does make a difference, but its rotation goes from dry to weak effect to dry.

Make sure that you tweak the trim pot with the mix pot at 50% for maximum phase. If you go full wet on the mix pot, the effect us actually not very strong. Also, sometimes it's best to set the trim pot in the 6 stage position; sometimes you want to split the difference on the trim pot between the best sound at 6 and 4 stage.

lk155 wrote:
IF my jumper is indeed the fix for my IC4 problem, I will solder it in place on the bottom of the board. Is there a better place to pick up the 9V I need at IC4 pin 8 rather than at IC3 pin 8? I just put my temporary jumper there because it was close to IC4.

Apologies for this - I read one of your posts wrong and thought that you had said you DID have continuity. There is no problem installing a permanent jumper where you have it. Anywhere you see "+9v" on the schematic is a fine place to attach the jumper.

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PostPosted: Mon Jan 09, 2017 12:47 pm 
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No apology necessary. I did at one point say I had continuity all all pin 8's. Now I do not. I suspect my many reflows of the IC4 pin8 socket made the situation worse. It's pretty clear that my earlier ham-handed solder removal efforts have made that spot on the board totally inoperative. At any rate, I'll carry on with soldering in this jumper and move on to the next issue, which is: very little phase effect.

Found an older post about a similar low-effect situation, and followed your advice on that one.........
Voltage at middle lug of depth pot (turned fully on) is steady at 3.86V, not oscillating.
Voltage at striped end of the 5.1 diode is 3.88.
Do these voltages lead to any conclusions? Or a remedial course of action?


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PostPosted: Mon Jan 09, 2017 2:40 pm 
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lk155 wrote:
Found an older post about a similar low-effect situation, and followed your advice on that one.........
Voltage at middle lug of depth pot (turned fully on) is steady at 3.86V, not oscillating.
Voltage at striped end of the 5.1 diode is 3.88.
Do these voltages lead to any conclusions? Or a remedial course of action?

That actually might be sort of good news. The oscillation relates to the rate pot/LFO. If the voltage at the depth pot is not oscillating, that indicates the LFO is not providing the oscillating voltage which creates the phase sweep. The LFO is usually pretty easy to get working compared to an unknown reason why no phase is happening.

Does your rate/speed pot do anything when the circuit is in effect mode?

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PostPosted: Mon Jan 09, 2017 3:07 pm 
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Speed pot, turned from full CCW to full CW, only dulls the highs somewhat around the mid position, then the highs come back as you turn it more towards fully CW.
This is with depth on full CW, resonance full CCW, mix about 50%.


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PostPosted: Mon Jan 09, 2017 4:23 pm 
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Okay, so time to work on the low frequency oscillator (LFO) portion of the circuit. This section is currently not working and you will not get any phase until it is working.

The LFO consists of IC1, IC2, the depth pot, the speed pot, R32-R36, and C14-C15.

Visually check all of those component values, orientation of IC2 (underneath the pcb) and C14, and check/reflow those solder connections. Voltages from IC2 wouldn't hurt. You should have similar voltages as the other ICs EXCEPT that pins 1-3 are usually weird because they are left unconnected and pins 5-7 will oscillate when the LFO is working.

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PostPosted: Mon Jan 09, 2017 6:56 pm 
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OK, I've done all the things you recommended, and I think I've got this narrowed down to a bad board connection at IC1 pin 7. That's another of the ones I dug out with a compass point after accidentally filling it with solder, just like the one on IC4 pin8.
I've just desoldered, cleaned, and resoldered that point a couple of times but I'm not getting continuity with R34, C15, or lug 3 of the speed pot.

IC2 voltages are: pin1: 3.96, pin2: 3.96, pin3: 3.94 slowly falling to 3.77, pin4: 0, pin5: 1.27, pin6: 1.69, pin7: 8.68, pin8: 9.15.

From what I can see of the schematic, IC1 pin 7 needs to connect to BOTH R34 and C15, which would mean I need to construct two very short jumpers, one from IC1 pin 7 to R34, the other from IC1 pin 7 to C15. Does this sound reasonable? I'm going under the assumption that the board trace on IC1 pin 7 no longer exists.

Damn. This is painful. And made even more painful by knowing it's entirely my fault for not having the right tools (specifically speaking of the desolder braid) at hand when doing the build.


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PostPosted: Mon Jan 09, 2017 8:01 pm 
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More news. And good news this time. In fact, TERRIFIC news!

IT'S ALIVE!!!! (Think of the lab scene in Young Frankenstein.)

It took another couple of tries to get a solid solder joint at IC1 pin7, but it finally happened.
It phases, yes indeed. All the pots work as they should. The switch makes a noticeable difference.

I'm happy as a clam.

All that remains is a bit of fine tuning with the trim pot, then I can bundle it all up and get it into the enclosure.

I'm going to call this one my $10,000 pedal. If I was still working (I'm not, because I'm supposed to be retired now, with plenty of time to fiddle with guitar stuff), the time I've spent on this thing would have resulted in client billing of somewhere between $8K and $10K.

Many, many thanks to the folks here. My gratitude for hanging in there with me goes out to Morgan, BYOC, and Duhvoodooman. Obviously, I couldn't have made this work without you.
Now I need to go finish up. Hope there's no more soldering involved.
Cheers and thanks again,
Lyle


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PostPosted: Mon Jan 09, 2017 8:04 pm 
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Good job sticking with it Lyle. :wink:

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PostPosted: Mon Jan 09, 2017 8:20 pm 
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Morgan wrote:
Good job sticking with it Lyle. :wink:

And a yeoman's job of providing tenacious support by you, Morgan!

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