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Current lover frown :(

Started by TNblueshawk, June 05, 2012, 09:35:41 AM

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TNblueshawk

Ok, finished this thing this morning before I took off for work. So I ran out of time for voltage readings and stuff. Figured I'll start this thread and if anyone has any off the cuff thoughts I'll take those home with me as I take a bunch of readings.

First, using RR to power at 15v. Power seems to be fine as I get 14.85v going into the board at the 9v pad.

Doing the MN3007 version. Every part is right to spec on the BOM. I didn't change anything. Chip from Smallbear. Had it stuffed in the pink foam until I installed it.

Thus far, bypass signal is fine BUT for one thing. I get a fairly loud fast clicking in bypass. Sort of has that film projector sound of the film clicking away...that's what it reminded me of. Seems to me I should not have that going on in bypass. But for that I get full signal.

Kick on the effect, nada or so I thought. Turned the amp to 6 and I get a faint, very faint, signal coming through. This is where I ran out of time and and had to go to work. Idid play with the trimmers  a tad and got no effect at all on anything. I was using the bias technique in the build docs.

Any way, if you have any thoughts today please send them my way and I'll add to my list of to do's.


John

jimmybjj

 the resistor teepee at the bottom of the picture looks like it might be grounding out. On my iphone so not sure.
Pcbs no longer available

TNblueshawk

That one is fine. The board is just resting there but it is not touching. I picked up that board while playing around with it so it was not grounding. I had it taped down as well but pulled the tape. However, that is something I need to keep an eye on for sure while continuing to troubleshoot. Thanks Jimmy.
John

TNblueshawk

Ok, here we go. Whew that is a lot of voltage readings and typing.

First order of businees. I always get confused with the there toggles so for example on my picture where you see the word "filter" if the toggle is to the right, ie. over to the side where the word "filter" is printed that means the filter is NOT engaged right? It works intuitively opposite correct?

Second comment: the only IC I have that is not of the exact designation as what Bean has in the BOM is the 4013. Bean has BCN and mine is BE. I know a lot of times it doesn't matter but since I have a build issue and we all know the S in SCPA actually means something I wanted to put that on the table.

Thirdly, I read a several troubleshooting threads here before posting. A discussion was in one of them about the pin out being different from several manufacturers. A little confusion here by me. First, I have the 3 trannies placed exactly like on the PCB. In looking at the data sheets I notice for 3904 and 5087 it has for 1=E and 2=B and 3=C however for the 5088 it has 1=C and 2=B and 3=E. So, do I have them placed right on the board I guess is my question now? Again, stock to the BOM and stock to the placement on the PCB.

Ok, on to the good stuff:

Switch RIGHT towards "filter"   Switch LEFT opposite "filter"
JRC4558   JRC4558 Exact Same
Pin 1: 7.38   Pin 1: 7.38
Pin 2: 7.38   Pin 2: 7.38
Pin 3: 3.67   Pin 3: 3.67
Pin 4: 0   Pin 4: 0
Pin 5: .19   Pin 5: .19
Pin 6: 10.47   Pin 6: 10.47
Pin 7: 13.88   Pin 7: 13.88
Pin 8: 14.69   Pin 8: 14.69
   
MN3007   MN3007 Mostly the same
Pin 1: 14.57   Pin 1: Same
Pin 2: 6.50   Pin 2:   "
Pin 3: 6.05   Pin 3:  "
Pin 4: 0   Pin 4:   "
Pin 5: 0   Pin 5:   "
Pin 6: 6.54   Pin 6: 7.00
Pin 7: 5.09   Pin 7: 5.34
Pin 8: 5.10   Pin 8: 5.35
   
4049   4049: All within .3-.5v more
Pin 1: 14.57   Pin 1:
Pin 2: 6.57   Pin 2:
Pin 3: 6.60   Pin 3:
Pin 4: 6.60   Pin 4:
Pin 5: 7.06   Pin 5:
Pin 6: 6.67   Pin 6:
Pin 7: 7.06   Pin 7:
Pin 8: .01   Pin 8:
Pin 9: 6.65   Pin 9:
Pin 10: 6.50   Pin 10:
Pin 11: 6.67   Pin 11:
Pin 12: 6.50   Pin 12:
Pin 13: 0   Pin 13:
Pin 14: 6.50   Pin 14:
Pin 15: 6.56   Pin 15:
Pin 16: 0   HUH???   Pin 16:
   
4013BE not 4013BCN?   4013BE not 4013BCN?
Pin 1: 7.04   Pin 1: 7.20
Pin 2: 7.05   Pin 2: 7.20
Pin 3: 9.25   Pin 3: 11.60
Pin 4: 0   Pin 4: 0
Pin 5: 7.06   Pin 5: 7.20
Pin 6: 0   Pin 6: 0
Pin 7: 0   Pin 7: 0
Pin 8: 0   Pin 8: 0
Pin 9: 0   Pin 9: 0
Pin 10: 0   Pin 10: 0
Pin 11: 0   Pin 11: 0
Pin 12: 0   Pin 12: 0
Pin 13: 14.68   Pin 13: 14.70
Pin 14: 14.67   Pin 14: 14.70
   
LM324   LM324 mostly same but .2v less
Pin 1: 7.35   Pin 1:
Pin 2: 7.35   Pin 2:
Pin 3: 6.70   Pin 3:
Pin 4: 14.66   Pin 4:
Pin 5: 2.37   Pin 5:
Pin 6: 2.45   Pin 6: 1.70
Pin 7: 4.10   Pin 7: 7.35
Pin 8: 7.00   Pin 8:
Pin 9: 6.70   Pin 9:
Pin 10: 6.80   Pin 10:
Pin 11: 0   Pin 11:
Pin 12: 6.70   Pin 12:
Pin 13: 6.80   Pin 13:
Pin 14: 6.75   Pin 14:
   
LM311   LM311
Pin 1: 0  HUH ????   Pin 1: 0  HUH ????
Pin 2: 3.95   Pin 2: 7.05
Pin 3: 2.50   Pin 3: 4.3
Pin 4: 0   Pin 4: 0
Pin 5: 14.66   Pin 5: 14.70
Pin 6: 14.66   Pin 6: 14.70
Pin 7: 9.60   Pin 7: 11.70
Pin 8: 14.66   Pin 8: 14.70
   
   
Trannies: E, B, C   Trannies: E, B, C
Q1 3904   4.98; 5.57; 14.60   5.20; 5.70; 14.68
Q2 5087  14.18; 12.82; 2.50   14.18; 12.82; 4.34
Tranny: C, B, E   
Q3 5088  1.87; 0; 8.40   1.87; 2.30; 8.40

Any thoughts fellow pedalers?
John

TNblueshawk

Addendum. I had cut and pasted out of Excel so sorry for the columns being a little screwy.
John

LaceSensor

If it helps I used a Texas instruments 4013 BE in my build and it works a-ok.


TNblueshawk

Quote from: LaceSensor on June 06, 2012, 08:32:14 AM
If it helps I used a Texas instruments 4013 BE in my build and it works a-ok.



Thanks Lace. That rules out that as a variable at least as mine is a TI too.
John

TNblueshawk

Got home and reflowed the joints.

What might cause volume loss?

The deal is if I max the volume and max my amp I get a signal. All the knobs affect it so I would say the wiring is correct probably here. I could probably bias it now but I'd rather figure out my volume loss.

Any thoughts on what could cause the volume loss like this but when cranked it seems the pedal would be fine.

Just popping on to give clues in case I can't figure that one out.
John

TNblueshawk

Me again. More info. Guess I've scared everyone off. Oh well, this is cathartic anyway.

El Danko, I hope this isn't my "Moby Dick"  :P

Checked vol pot and it is 100kA. At halfway you can barely hear anything. At max I get a decent amount of volume. Enough that I biased this puppy.

So I checked all the cap values. Thought I stumbled onto something when I had a 33n instead of a 68n. Swapped and my hopes were dashed..no change.

Took more voltage readings of the toggle.

With switch in the "up" I guess or with it again on the same side of the word "filter" on the PCB:

Pin 1: 0
These all vary up and down so the below is the max vots
Pin 2: 2.2
Pin 3: 2.2
Pin 4: 1.7
Pin 5: 2.2
Pin 6: 3.05

Toggle in "down" or opposite of "filter"
Pin 1: 0
Pin 2: 0
Pin 3, 4, 5 = 1.69
Pin 6 up and down max is 3.05

I don't know what other voltage readings to take that matter.

This is a stumper as I basically have a working pedal at 20% or so volume.

Next up I guess is resistor values. I know a screw up here "I think" can cause a volume issue? Saving those for last as I don't have color codes memorized and of course I can't just pop the DMM on them soldered in. This will take awhile.

If anyone wants to jump in I'm all ears.
John

LaceSensor

Here the goods on mine. This was in the flanging position of the switch.

supply - 9.4V

LM311
1-0
2-varies
3-varies
4-0
5-9.2
6-9.3
7-varies
8-9.2

MN3007
1-9.4
2-4.2
3-3.6
4-0
5-0
6-4.6
7-3.6
8-3.7

JRC4558
1-4.9
2-4.7
3-2.3
4-0
5-4.2
6-4.7
7-4.7
8-9.3

4049
1-9.3
2-4.5
3-4.5
4-4.5
5-4.6
6-4.5
7-4.6
8-0
9-4.6
10-4.4
11-4.6
12-4.6
13-0
14-4.7
15-4.7
16-0

4013
1-4.6
2-4.6
3-7.4
4-0
5-4.6
6-0
7-0
8-0
9-0
10-0
11-0
12-0
13-9.2
14-9.2

LM324
1-4.6
2-4.6
3-4.2
4-9.2
5-1.4 - 2.0 ish
6- varies
7- varies
8-jumps 0.6 up to 7.5 and back
9-4.2
10-varies
11-0
12-4.2
13-4.3
14-varies

Hope that is of use

TNblueshawk

Thanks Lace. I actually pulled your voltages from a thread in the past and used that to extrapolate what I should have had at 15v. I opened up a thread at BYOC http://www.buildyourownclone.com/board/viewtopic.php?f=9&t=38109 and a couple mods are really digging in trying to help.

Bottom line is I have a short somewhere on its way to IC1, JRC4558. My voltage readings at pins 3, 5 and 7 are way off. But, for the life of me I couldn't find it last night. Reflow, things "look" good, swapped out the chip with 3 different ones etc... Looked down at one point and R33 was almost on fire bubbling which is located right next to the 9v pad. Not sure what caused it to do that. I was reading the schematic when I started to smell something  :o :-\

Where in the hell is this short !!!!!!!!!!!!!!!!!!!!!!!!

John

eldanko

How'd you know I was watching this thread  ;D

You're still ahead of me, mate.  Sorry I don't have any help to offer at the moment, but it sounds like you're close...
www.danekinser.com - Music, Builds, other nonsense

TNblueshawk

Updating this for anyone that had the guts to follow and in case it helps anyone  :P

It's fixed but for what is a small issue. I'm not sure what the issue WAS but I guess I had a bad connection at R7. Odd since I inspected and reflowed those joints adding solder etc... After buthering the pad from desoldering I "hard wired" it again underneath. Bottom line is I'm getting some great flange. Still need to bias.

Now, my voltages were off on IC1. That are all back in line but for one, on pin 3. I'm still only getting 3.68 volts (running this off 15v).

Can't decide if that is an issue or I should just roll with it and leave well enough alone. Can't help but think that pin needs to be closer to spec. My voltages on R3 are 3.68 on both ends and then of course 3.68 going into R4 but as it leaves R4 I'm getting 7.35. Not smart enough to know how that is possible.


John

Scruffie

Quote from: TNblueshawk on June 12, 2012, 07:30:47 AM
Updating this for anyone that had the guts to follow and in case it helps anyone  :P

It's fixed but for what is a small issue. I'm not sure what the issue WAS but I guess I had a bad connection at R7. Odd since I inspected and reflowed those joints adding solder etc... After buthering the pad from desoldering I "hard wired" it again underneath. Bottom line is I'm getting some great flange. Still need to bias.

Now, my voltages were off on IC1. That are all back in line but for one, on pin 3. I'm still only getting 3.68 volts (running this off 15v).

Can't decide if that is an issue or I should just roll with it and leave well enough alone. Can't help but think that pin needs to be closer to spec. My voltages on R3 are 3.68 on both ends and then of course 3.68 going into R4 but as it leaves R4 I'm getting 7.35. Not smart enough to know how that is possible.



Cause your multimeter is too low an impeadance to read the voltage properly for something biased at 1M  :)
Works at Lectric-FX