[shrimants]

i'm building the Y1 and in the description for C4u and C5u it says "multilayer ceramic capacitor C0G/NP0 33pF 100V", but the mouser AND digikey parts it lists are 200V rated. Is this still the right part or is there a typo on the site?

 

[MisterX]

Try finding 33pF, C0G/NP0, through hole, ceramic capacitors with .1" lead spacing at Mouser and Digi-key and see if it clears things up for you.

(it's not a typo)

 

[shrimants]

thank god, because i definately just said eff it and put them in there. I'm now done with all resistors, capacitors, and inductors and most of the semiconductors except the input/output things and also i have to do the networked resistors and the jumpers. thats gonna take some more reading on my part, along with how to properly test.

Another question, somewhat unrelated to the topic, I now have a healthy layer of paste flux all over my board. I have like 90% rubbing alcohol available but I'm afraid it will mess something up, plus i have no idea how to use it to clean off the flux effectively (ie without pouring the bottle out over the board)

 

[MisterX]

Do you have an almost empty spray type dispenser bottle (glass cleaner or the like) somewhere you can re-purpose?
Dump out the original contents, rinse it out good, fill it back up with the rubbing alcohol and then maybe re-label it so the next someone won't try to clean her car windows with it and then holler at you because she didn't notice it wasn't window cleaner.

 
 

 

[shrimants]

good thinking, i do. I have one that i used to spray my cat when she was being a bad kitty but she got the message so well that even if i point at it she runs away.

Also, just to make 100% certain, that 200V rated capacitor is OK to use right? I've only taken a very basic course on circuit laws and reason tells me it should be fine, esp. because we wont be generating 200V on a 5v input board anyways without a giant transformer....

 

[jdkJake]

Regarding cleaning your board: I, like others, have found a cheap nylon bristle toothbrush and the alcohol you already have make an effective method for cleaning flux off of a board. Firm, but gentle scrubbing using a light spray of alcohol should work fine. Rinse and repeat until the board is nice and clean.

 

[jdkJake]

Regarding the capacitor: In this case, they higher voltage rating is fine as long as the capacitor type, the rated capacitance, and the size of the part are appropriate. You can always go up on the value of a rated part, you just can not go down (in most cases).

 

[shrimants]

I got my spray bottle to spray the alcohol in kind of a pressure washer way. I'll look around for a nylon brush, im sure there is one somewhere around the house.

My only concern: the alcohol left this whitish residue in some places.....dont know if thats bad or what.

 

[jdkJake]

That's just impurities left in the alcohol. If you can get better than 90%, then that becomes less of an issue.

You can also sop up the excess using a towel, which reduces the amount of residual. Personally, I have access to a blow dryer that has a cool setting (air only, no heat) that I use to blow off the residual alcohol. Works fine.

 

[MisterX]

I'm betting the white residue is from the flux, not the alcohol.
 
 
Spray some of the alcohol on a piece of glass, let it evaporate and check if what's left looks anything like what you see on the board.

 

 

[shrimants]

I finished both boards and unfortunately I am not getting sound. heres what i've noticed so far.

1) I plugged the boards into each other and they didnt sit flush with each other.
2) the boarsARE recognized as USB Audio DAC, and the computer sends sound to it.
3) I tried testing the voltage on the USB pins thinking it should be getting 5V, but the volt meter didnt read more than 1. this tells me that either the meter is broken/out of batteries or that I dont know how to use a volt meter. The second possibility seems unlikely since I would have failed my circuits lab course.
4) I dont know how to test if the problem is in the Y1 only or the Y2 because the Y1 wont work without the Y2 plugged in. only the USB board will work.
5) There are no solder bridges, though there might be cold joints. I already went through and resoldered everything that wasnt completely shiny silver.
6) the bicolor NKK switch broke and i ordered a replacement, but for now the LED is only red. I DID try to set it to the middle setting and that made no difference
7) I had difficulties on the connectors and had to do a lot of deslodering/resoldering on them. I think I possibly ruined the 3p and 5p receptacles, which is probably why the boards arent sitting flush. I already ordered 4 sets of replacements.
8) I'm not getting proper ohm or voltage readings anywhere, possibly because of the multimeter.


Any help debugging this would be very much appreciated. 350 USD later and countless hours I really dont feel like trashing a near complete project. I havent given up yet.

 

[shrimants]

I decided that I will attempt to test the Y1 board as stand alone before even thinking about the Y2. My guess is that the pins and receptacles I used have gone bad from desoldering/resoldering multiple times. As I said earlier, I ordered 4 sets of 3 and 5 pin receptacles. The Y2 receptacles are in 100% condition because I didnt have to resolder them. The pins, though MIGHT need to be redone. With one of my 3p/5p sets i'm going to build a special cable that will mate the usb board to the DAC board on the Y1. That way, I dont have to mess with any cabling/uncabling on the bottom of the board. If the Y1 works by itself, the problem is obviously in the Y2 somewhere.

I'm also expecting there to be some cold joints on both boards, though apart from reheating the joint I have no idea how to fix this. I'll also try to watch some videos on how to use a multimeter properly because perhaps the probes were in the wrong spot or something. If you guys are willing to help I can also post some closeups of various parts of each board.

 

[jdkJake]

First, post some pictures. The best lighting and focus you can muster.

Second, use your multimeter to your advantage. Seat the y1 and y2 together and probe each side of the pins/receptacles. There should be continuity between each pin/receptacle. If so, then you do not need to replace them as they are fine. In my experience, the y1/y2 do not seat exactly flush, but, are electrically connected.

Did you follow the power-up check out sequences that AMB outlines on his site?

 

[shrimants]

Ah! thank god someone finally answered! lol

I did do the power on routine and also the ohms routine for both boards. For the Y1 I got a "0L" reading for all the JP2D readings and a "0" reading while testing continuity between the chip lead and the pad. On some places I wasnt able to test the chip and pad quite right because I installed the chip ever so slightly crooked and there wasnt enough pad left for me to test. The actual chip lines up and everything, its just that I couldnt test the pad itself for 1 or 2 of the chip pins.

The problem came up on the Y2 board. When I did a test for voltages on the voltage pads I consistently got a 0L reading, which is what lead me to believe that the problem is in the receptacles. However, when I tested between pin receptacle and ground I never got a value over 1 volt and only a couple of the pins actually gave me that reading. This was true for both the receptacle and header on the Y2 board. I'm not entirely sure if I checked the Y1 board's receptacle/header.

I'll take your advice and test for ohms between Y1 and Y2's pin/receptacle, I cant believe i didnt think of that.

Also, my girlfriend is hardcore into photography so I'm gonna let her take my mom's EOS20D for a spin, build a nice white backdrop, and have her take some good infinite focus pictures. I might even bust out the tripod and remote shutter release finally

I'll also do my "custom y1 cable" idea when I get my extra receptacles (and switch) in the mail.

 

[shrimants]

Alright, I took the pictures and tested the jumpers as jdkjake suggested. The first time around the 5p receptacle on the Y2 did showed 0L on 4/5 pins. I tested the Y1 board's pins for that side and they showed 0 resistance so I figured the Y2 pin receptacles were the problem. I only did a single installation of those though (no solder/resoldering) so I found it hard to believe that those were the problem. I plugged the boards in again and then all the pins showed that they were conducting just fine. No idea what happened there...... Also, the DMM I have for some reason only works on the 2k ohms setting (ie it tells me there is .000 ohms resistance. If I try to put it to ohms, it just says "0L". I tested it on a 560 ohm resistor and on the setting labeled 200 it registered 0L, but on 2K it registered .560 ohms, which was correct. I dont know if this meter is faulty or low on batteries or what.

Without further ado, here are the pictures. I tried getting a more close up shot of the chips on the Y2 because that might be where there is solder bridges or some such thing but this camera has a telephoto lens and a standard lens that both refuse to take closeups of small objects. Neither are macro lenses. I'll see what I can do with a standard point and shoot later on...











If you want, I can also email you the full resolution pictures. They are about 20MB total.