Neovibe Debug Help

[tr1p1n]

he wants to make sure there is no issues with those transistors..look at mammoth electronics online..they sell those 3 pin tranny sockets for 45 cents as compared to small bear at 1.09 they have better prices and usually ship the same day

http://www.mammothelectronics.com/TO-18-Package-Round-Tansistor-Socket-p/620-to18.htm  these? so pretty much you solder these in and switch transistors in and out without any problems?  dang wish i knew about these before i went ahead and almost murdered the board haha.

[lonewolf]

yes ..those should fit on that  board..I cant say for sure since I made my clone with a perfboard point to point..but I always use sockets

[tr1p1n]

yes ..those should fit on that  board..I cant say for sure since I made my clone with a perfboard point to point..but I always use sockets

Well for 45 cents a piece sure as hell wouldn't hurt to try especially since I'm going to continue building pedals. I'm sure eventually they'll be put to good use, one way or another.

[R.G.]

Still working on removing them but I think I see the problem or a problem, isn't there supposed to be an orange trace between R40 and Q11 base? when I double checked continuity (this morning) it was connecting, now when I have removed the pin it looks like there never was even a trace there to begin with.

Hmmm. You're getting the idea now - anywhere there's a solid line on the schemo, the end points should show about the same reading as touching the two ohmmeter probes together. If it appears there's no trace, put the ohmmeter probes on the pads on each end. Copper traces can be so thin that the solder mask coating can make them hard to see.

Ohmmeter test shows 0 for emitter and base (wasn't sure how to test exactly so i stuck a probe in one emitter and one in the other) but for the collectors it's hard to get an exact reading sometimes it stays at 10 other times it up to 200 something for a bit. Mostly around 35.5 - 45.

Ohmmeter (resistance) or voltmeter test?

Q11
C=27.5v
B=0
E=0

Q12
C=27.5v
B=0
E=0

If the base of Q11 shows zero volts with the power on and Q11 out of circuit, then the path through R40 is indeed open.

And another thing, I did mention before that a contact ring thing came off of Q11 emitter (bottom of PCB) now I notice it's also missing from the top and Q11 base is missing too just from the bottom. Not to mention Q12 emitter is so warped, it's still on there I just mean it looks like it's about to come off. Also not sure if it has any correlation or it's just because I removed the transistors but while measuring voltage just went around the caps again and now C16 seems to be messed up.

You have soldering issues; this is to be expected for how much experience you have under your belt. First a little side trip.

The copper foil is attached to the PCB insulating material by a layer of epoxy when the stuff it made. It's good epoxy, but all epoxies soften when heated too much or too long. PCB soldering should be as quick as possible to not let this go too far. If your iron is not hot enough or has insulating oxide gook on the outside, it takes so long to melt the solder that the epoxy gets cooked, softens and turns loose with any pressure. It happens to all of us - me, especially - and it's just something to watch for and try to develop the skill level to avoid. Sometimes the pad only moves a little bit, but this may crack thin traces leading to the pad right where the trace contacts the pad, as this is a high stress area.

I know all this by making the mistakes myself, so don't be too hard on yourself. Education and skill take time. If you're still having big problems with this a year from now, then worry.

It sounds like there is copper-trace damage. No fun, but it happens. That's why the leads on components are longer than they have to be.  For the transistors, Q11/12, I personally would use a magnifier and ohmmeter to make sure the remaining traces are not shorting where they should not be, then stick the uncut 1" or so leads of replacement transistors through the existing holes, bend in the way they should go, and scrape the solder mask away from the copper trace under the lead when you get to good, firmly attached lead, and lap-solder the lead onto the trace. I'd use the cut-off-resistor lead trick when needed.

Once you've done this, use the meter set to ohms and find out whether the connections actually match the schematic or not. One good way to avoid schematic-blindness is to print the schematic, then use a colored marker to keep trace of place-to-place connections as you verify them.

[lonewolf]

you can also get them straight in line and you just break them off ...I get em on ebay mega cheap
look for are8-department -store  they have single in line sockets for a couple of $$(2 times 30=60) small bear and mammoth want almost 3.00 for 36 of them plus the shipping
that loud hum you talk about sounds to me like it is a open ground in the audio path.. I would take some time and check everything that connects to ground from Q1 to Q 10 and especially Q1/2/3..that is the dry signal chain..I had a problem there that caused a loud distorted humming noise...

[tr1p1n]

Still working on removing them but I think I see the problem or a problem, isn't there supposed to be an orange trace between R40 and Q11 base? when I double checked continuity (this morning) it was connecting, now when I have removed the pin it looks like there never was even a trace there to begin with.

Hmmm. You're getting the idea now - anywhere there's a solid line on the schemo, the end points should show about the same reading as touching the two ohmmeter probes together. If it appears there's no trace, put the ohmmeter probes on the pads on each end. Copper traces can be so thin that the solder mask coating can make them hard to see.

Ohmmeter test shows 0 for emitter and base (wasn't sure how to test exactly so i stuck a probe in one emitter and one in the other) but for the collectors it's hard to get an exact reading sometimes it stays at 10 other times it up to 200 something for a bit. Mostly around 35.5 - 45.

Ohmmeter (resistance) or voltmeter test?

Q11
C=27.5v
B=0
E=0

Q12
C=27.5v
B=0
E=0

If the base of Q11 shows zero volts with the power on and Q11 out of circuit, then the path through R40 is indeed open.

And another thing, I did mention before that a contact ring thing came off of Q11 emitter (bottom of PCB) now I notice it's also missing from the top and Q11 base is missing too just from the bottom. Not to mention Q12 emitter is so warped, it's still on there I just mean it looks like it's about to come off. Also not sure if it has any correlation or it's just because I removed the transistors but while measuring voltage just went around the caps again and now C16 seems to be messed up.

You have soldering issues; this is to be expected for how much experience you have under your belt. First a little side trip.

The copper foil is attached to the PCB insulating material by a layer of epoxy when the stuff it made. It's good epoxy, but all epoxies soften when heated too much or too long. PCB soldering should be as quick as possible to not let this go too far. If your iron is not hot enough or has insulating oxide gook on the outside, it takes so long to melt the solder that the epoxy gets cooked, softens and turns loose with any pressure. It happens to all of us - me, especially - and it's just something to watch for and try to develop the skill level to avoid. Sometimes the pad only moves a little bit, but this may crack thin traces leading to the pad right where the trace contacts the pad, as this is a high stress area.

I know all this by making the mistakes myself, so don't be too hard on yourself. Education and skill take time. If you're still having big problems with this a year from now, then worry.

It sounds like there is copper-trace damage. No fun, but it happens. That's why the leads on components are longer than they have to be.   For the transistors, Q11/12, I personally would use a magnifier and ohmmeter to make sure the remaining traces are not shorting where they should not be, then stick the uncut 1" or so leads of replacement transistors through the existing holes, bend in the way they should go, and scrape the solder mask away from the copper trace under the lead when you get to good, firmly attached lead, and lap-solder the lead onto the trace. I'd use the cut-off-resistor lead trick when needed.

Once you've done this, use the meter set to ohms and find out whether the connections actually match the schematic or not. One good way to avoid schematic-blindness is to print the schematic, then use a colored marker to keep trace of place-to-place connections as you verify them.

There's definitely no trace or copper anything for that matter, it's gone. As for the second question Ohmmeter.  The base of Q11 reads .5mV.....And so you're saying for the leads I should just bend them to where they have to go then solder that lead to the component and scraping the solder mask? I'm not sure what you mean by that.

[lonewolf]

if you have a broken trace between 2 points on the board you just connect a piece of resistor wire between those 2 points..if you have a pin sticking up thru a hole you can bend the end of the resistor wire to form a circle to fit around the component pin..lay it flat and hold it in place with a piece of masking tape..then solder the connection...then just bend the wire until it connects with the component it is supposed to connect to..then solder that end..if you have to you can insulate the resisror wire with a piece from a regular wire...you can solder to a trace if it is big..just hold everything in place with painters masking tape..you can also stick the resistor wire in the hole if there is a pad left and clean the two points with your braid..you need a fine pencil tip on your iron..and use a good iron,not a radioshak piece of junk...

[tr1p1n]

if you have a broken trace between 2 points on the board you just connect a piece of resistor wire between those 2 points..if you have a pin sticking up thru a hole you can bend the end of the resistor wire to form a circle to fit around the component pin..lay it flat and hold it in place with a piece of masking tape..then solder the connection...then just bend the wire until it connects with the component it is supposed to connect to..then solder that end..if you have to you can insulate the resisror wire with a piece from a regular wire...you can solder to a trace if it is big..just hold everything in place with painters masking tape..you can also stick the resistor wire in the hole if there is a pad left and clean the two points with your braid..you need a fine pencil tip on your iron..and use a good iron,not a radioshak piece of junk...

Alright so I finally went ahead and soldered them in. Connections are OK volts remain pretty much the same.

Q11
C=27.5v
B=13.66v
E=27.5v

Q12
C=27.5v
B=27.5v
E=8.46v

And any reason why I can't even get a reading on the right side of R41? I don't know if its because the transistors aren't functioning properly or what but I cant get a reading on that side all the way up the trace to the other side of R46 let alone anything along from that trace all the way around the board. And the bottom of R44,45,46 that one trace that connects them all the way to J1 I can take the black probe, slap it on the right side of R41 and rub the orange trace (the R44-46) one with the red lead and the lamp starts going on and off. I don't know if this means anything but I thought I'd bring it up.

[R.G.]

Alright so I finally went ahead and soldered them in. Connections are OK volts remain pretty much the same.
Q11
C=27.5v
B=13.66v
E=27.5v

Q12
C=27.5v
B=27.5v
E=8.46v

This means that there is still a non-connection or bad connection you have not found.

And any reason why I can't even get a reading on the right side of R41? I don't know if its because the transistors aren't functioning properly or what but I cant get a reading on that side all the way up the trace to the other side of R46 let alone anything along from that trace all the way around the board. And the bottom of R44,45,46 that one trace that connects them all the way to J1 I can take the black probe, slap it on the right side of R41 and rub the orange trace (the R44-46) one with the red lead and the lamp starts going on and off. I don't know if this means anything but I thought I'd bring it up.

It's very significant.

1. When you "can't get a reading" what is your meter setting? Volts? Amperes? Resistance?
2. Overall what you're telling us is that there is an open connection somewhere in the area you're probing. The trace that runs all the way around the board is ground, the board's local reference for 0V. So it's important that you see 0.00000V  plus or minus your meter's internal offsets and errors, all the way around it when the power is on, and find zero Ohms of resistance as near as your meter can read that, all the way around it when the power is off.
3. The meter setting matters. If you can probe two different points and the thing starts working (that's what that light going on and off is) then you'r'e probing points that need to be connected somehow. The setting of the meter makes a big difference here, because when you switch the meter settings, the probes become different things to the circuit. As a voltmeter, they look like a big resistor, perhaps 1M or 10M, to the circuit. Set to the current ranges, the probes become a low resistance so as to not disturb the current they read. And set to resistance, the probes become a source of low voltage DC to push current through a resistor to be measured.

At this point you have localized the problem to a very small bit of the circuit. I think the best way to proceed is to do a bit more voltage measurement. Only this time, we'll need to be careful. We need to measure all pins of every part in this section of circuitry. This may be enough to tell us where the problem is exactly.

For this test, you will need to set your meter to read DC volts, and connect the black probe to ground.

So once again measure voltages and list back here, all pins of :
R39 through R46
C19 through C23
Depth and speed pots

For this test leave the black (common, if it's marked that way on your meter) probe connected to ground for all of them.

[tr1p1n]

When I couldn't get a reading it was set to Volts. Just found it odd everything was displaying something but when I approached the other side of the board (opposite R44,45,46) nothing was showing up.

As for the readings.
L=Left Side R=Right Side (+,-) For the caps and when I say T=Top B=Bottom. I mean Bottom being the R44,45,46 Trace that connects them all and of course Top being opposite where they branch off.

R39                                                      C19
L=15.98V  R=27.5V                                += 13.05V  -= 8.54V
R40                                                      C20
L=15.96V  R=13.30V                              += 8.53V    -= 8.53V
R41                                                      C21
L=15.94V  R=0                                       += 191mV  -= -007mV
R42                                                      C22
L=8.52V  R=8.52V                                  += 8.68V    -= 5V Before dropping.
R43                                                       C23                  
L=8.52V  R=8.52V                                  += 3.63V    -=2V Before dropping.
R44                                                      
B=8.68V  T=8.54V
R45
B=8.70V  T=8.54V
R46
B=8.71V  T=0


Depth - G=4.7V Before dropping.                                Speed - C= 8.68V
           H=1300mV Before dropping.                                         D= 8.51V
           F=0                                                                               E= 8.51V

I hope the orientation isn't confusing, tried making this as organized as possible without making the post a whole page. Also what I mean by "before dropping" take C22 for example, It starts out at 5V on the - side and will drop say .1 at a time. So for example I remove the probe after dropping to 4.86V I can come back 30 seconds later and it will pick right back up at 4.86V and continue to drop. I'm not sure what's going on but that was the weirdest thing I've encountered so far.

[R.G.]

Check C22 to see if it's inserted backwards or has some soldering difficulty.

The depth pot should be blocked from DC by C22 and C23, and should be 0V on all pins. The voltage could come from either C22 or C23, whichever has a problem, but if there is only one problem, the pin with the leaky capacitor attached to it will be the highest DC voltage. In this case that's C22.

Check C22 orientation, and if it is indeed properly inserted, it may have been damaged in the soldering process. In that case, remove it and replace it carefully with another.

Let us know what this does.

[tr1p1n]

Check C22 to see if it's inserted backwards or has some soldering difficulty.

The depth pot should be blocked from DC by C22 and C23, and should be 0V on all pins. The voltage could come from either C22 or C23, whichever has a problem, but if there is only one problem, the pin with the leaky capacitor attached to it will be the highest DC voltage. In this case that's C22.

Check C22 orientation, and if it is indeed properly inserted, it may have been damaged in the soldering process. In that case, remove it and replace it carefully with another.

Let us know what this does.

It's oriented correctly but it looks a tad bit on the "skimpy" side with solder (for lack of a better word). I'm going to re-flow and see if that changes anything because as of now I only have a few spare 50v 1.0uF caps and 1 35v 1000uF caps. If this doesn't work would you suggest any other parts I should order just in case? I don't have any electronic stores local that sell anything like this aside from radio shack but I checked their site already. Or better yet common household electronics that might harbor these? I don't know just trying to throw some ideas out there before we have to put this on hold to Wednesday or so.

And after the re-flow nothing changed as assumed. So I'll order a bunch of extra caps needed for this board tomorrow IF my search for a local store comes up empty. Two question's though do you assume both of them are damaged? Seeing as G and F have separate traces that lead to them and being that both of there negative sides drop or I guess leak the voltage slowly. Either way I'll get a few new ones of them regardless just thought I'd ask. And secondly could you explain this post to me? http://www.diystompboxes.com/smfforum/index.php?topic=96288.0  I have the LED and the 10k resistor already. It looks to be a 3DPT, DPDT and a On/Off toggle switch? Are these specific switches? and I guess the On/Off switch turns the power on and off. The 3DPT either turns the effect on or lets me bypass and does the DPDT switch between Chorus/Vibrato? Or do I still need my 3 lug toggle switch for the Chorus/Vibrato portion. And if the DPDT does now control the Chorus/Vibrato could I use my 3 Lug toggle switch for on/off or any on/off switch for that matter say a lightswitch? I could easily pull one from a broken amp if that would work. Or if you could explain this better to me cause seeing as I'm buying new parts I'd like to get these as well and anything you think I should get to have on hand also.

[lonewolf]

radio shack is very expensive...you should look online to find an NTE distributor..for local parts..

[tr1p1n]

radio shack is very expensive...you should look online to find an NTE distributor..for local parts..

Yeah, but it would be worth the money rather then the wait....no expense could be measured compared to my excitement/eagerness to get this to work. But lonewolf could you possible explain the previous thread for me? the one I asked R.G? But other then that I'm ordering from mammoth/mouser today so if you have any suggestions on parts I should get just in case to have in hand for this project that would be very much appreciated.

Any alternatives to 10uf 25v? Not sure what could be suitable besides those numbers or do they have to be that EXACT number? I've found 10uf 16v don't know if those would work.

[twabelljr]

Or better yet common household electronics that might harbor these?

I have salvaged ALOT of film and electro caps from old vcrs, tvs, and other electronics that I had around or people were throwing away. So far they have all been good. Avoid the electros from the power supply section as these seem to be the ones that go first. If they are bulging or leaking don't bother.  

[slacker]

....could you possible explain the previous thread for me? the one I asked R.G?

What you said is correct. The 3PDT switch is for bypass, the DPDT switch replaces the chorus/vibe switch, and the on/off turns the power on and off. You could use your existing chorus/vibe switch to do this, although I'm not sure what the point of an on/off switch is, just unplug it or turn it off at the wall when you're not using it.
I wouldn't worry about this until you've got it working.

[tr1p1n]

....could you possible explain the previous thread for me? the one I asked R.G?

What you said is correct. The 3PDT switch is for bypass, the DPDT switch replaces the chorus/vibe switch, and the on/off turns the power on and off. You could use your existing chorus/vibe switch to do this, although I'm not sure what the point of an on/off switch is, just unplug it or turn it off at the wall when you're not using it.
I wouldn't worry about this until you've got it working.

Thank you!!! and I don't know, already have the 3 LED why not put in the on/off function, all these bells and whistles would just further my excitement haha. But yes, this was planned AFTER i get this working.

[lonewolf]

you can go with a larger voltage if space permits but 16v caps in this device probably wont last as long..whatever the working voltage is you should go ten volts higher..the neo is 15v so at least 25...all that flashing led etc is a waste of time..you want to get it to pass a signal and then you will have more fun getting it to sound right....adding the 2nd trimmer for the bulb offset and the output mix mod (I used a 220k trimmer I stole out of a sony casette deck) and a 250k 20 turn trimmer for the bias offset that allowed me to tweek the bulb and get the best mix...
I have never fried a capacitor from soldering one in or removing one...what kind of iron are you using? what is the wattage   what size tip?..I use a weller WP25...25 watts..look at the NTE website and you can find a local distributor..maybe close to you..you can also get a iron/tips/wicks/solder..etc..radio shack is @@#&%^$^%!!!!

[tr1p1n]

you can go with a larger voltage if space permits but 16v caps in this device probably wont last as long..whatever the working voltage is you should go ten volts higher..the neo is 15v so at least 25...all that flashing led etc is a waste of time..you want to get it to pass a signal and then you will have more fun getting it to sound right....adding the 2nd trimmer for the bulb offset and the output mix mod (I used a 220k trimmer I stole out of a sony casette deck) and a 250k 20 turn trimmer for the bias offset that allowed me to tweek the bulb and get the best mix...
I have never fried a capacitor from soldering one in or removing one...what kind of iron are you using? what is the wattage   what size tip?..I use a weller WP25...25 watts..look at the NTE website and you can find a local distributor..maybe close to you..you can also get a iron/tips/wicks/solder..etc..radio shack is @@#&%^$^%!!!!

I think the flashing LED stuff is a bonus, useless like you said but a bonus haha. Anyways would that effect the circuit at all? and as for mods could you be more specific as to what exactly I need, just a list and I'll buy em (220k trimmer/250k trimmer bit I got so far but I did read something about R.G's wet and dry mix and getting a resistor to the nearest 1%? whatever that means). Haven't read much into what exactly you have to do but I'm sure you and R.G won't mind helping me. As for the soldering iron haha, well, was at auto-zone picking up a few things and was like "oh look a 5 dollar soldering iron, right up my alley" so as far as I know it's auto-zones 30 watt soldering iron pencil tip As for frying the cap not sure, R.G suggested the dropping voltages is because it's a leaky cap (caused from overheating?) Not really sure but I assume it's my fault regardless of what happened...Local distributor is outta the question, nearest one is hours from me I'm kinda out in the country. Ordering wont be so bad though, even if I want this fixed ASAP. Last time I ordered Thursday morning and got is Saturday morning so it was fairly quick. And yes so far my list contains extra caps/wicks and solder, most likely a whole new soldering iron too. Better yet I should just buy a new one.

[lonewolf]

get the weller iron it will  pay for itself because you wont have to replace the tips  and the heating element is replaceable too