Repair service [resolved]

[preston.ezell]

So I received my crack 1.1 and followed the guide perfectly. It worked and sounded so good! I was smiling from ear to ear listening to it with my HD6XXs. I ordered the crack with the speedball upgrade because of all the sound quality claims. Today I finished the speedball installation and everything measured correctly. I lost the Manuel file so I can’t remember what voltages I was supposed to have on everything, but something has gone terribly wrong. I don’t have any sound in my right channel. The left sounds good and without issue, but I have no right channel. I tried everything I know to do.

What happened to the repair service? I need the doc.

 

[Paul Birkeland]

Oh we still offer the repair service, but we hope that people can come here first for help, and that we can see a pic or two of any build before it gets sent in.  In your case, you could post your DC voltages on terminals 1-10 and we might be able to make some suggestions about what's going on, and build photos may also help us spot something too. 

 

[preston.ezell]

Okay, I can check these terminals when I get home from class. My initial crack 1.1 build complied with the expected values, so something definitely when wrong with the speedball installation.

I’m hoping I can get ahold of another pdf

 

[Paul Birkeland]

I mean you can post your voltages on terminals 1-10 here and we can go from there; the Speedball manual itself isn't 100% necessary.

 

[Jameson]

I'd definitely post voltages when you get back irrespective of whether you have the manual. I'd also try and fix it before you ship it to Bottlehead. Paul does great work, and I mean no disrespect in saying this - I don't think he'd disagree with me - but it's vastly cheaper to fix it yourself.

 

[Doc B]

Just post those voltages for terminals 1-10 and a good clear photo of the Speedball board installation. If you do that you needn't worry about resistors or manuals, and probably won't need to worry about repair service. If you can build it you can probably fix it.

 

[preston.ezell]

https://drive.google.com/drive/folders/1-0pw9LZF-D7ueBELUtM92PAhR_sd-lLd

Here’s what I have vs expected for both crack and speedball readings.

 

[Jameson]

I think you have a backwards PN2907A transistor (Position Q1A) on the front board, left side (A side).

 

[AB2KH]

YES, Q1A small board looks to be BAKARDS.

Chris/AB2KH

 

[Chris H]

Isn't the internet wonderful sometimes - diagnosed in 20 minutes, confirmation in 24.  For free!

 

[preston.ezell]

HOW DID I NOT SEE THIS. I was so careful. Lol

I will flip this when I get home and see if any other problems creep up. Will update tonight after my lab. I am currently studying the photoelectric effect for my physics lab lol now I’m nervous that I’ll never understand it based me overlooking something so simple as this. You guys are awesome. I love the internet.

 

[AB2KH]

A neutral set of eyes can very often see things you can't, you become "astigmatised" as to what you are working on. If I may add one constructive criticism - you should not paint the component side of your chassis plates it can cause connectivity issues.

Chris/AB2KH

 

[Chris H]

For that particular error I think the symmetry has something to do with not seeing it.
The two transistors are currently mirrored (incorrectly) so, once installed, simply don't look out of place alongside everything else also mirrored (correctly)

 

[preston.ezell]

I will always accept constructive criticism. I actually painted this side by accident. I thought it was the top when I started. Doh

And the symmetry is what I too expect to be the reasoning behind this. Everything else is installed in pairs with a mirror image. So expecting to find a component that opposes that rule was not on my mind.

Just got out of class. I look forward to seeing what happens next!

 

[Paul Birkeland]

Well done! 

 

[preston.ezell]

So it appears that flipping the transistor did not solve my issue. I still have 0 voltage at terminal 1 and 0 voltage at OA

 

[preston.ezell]

I checked the resistance of my 150kohm 2W resistors on the small board and the A side resistor is reading a varied amount that doesn’t really go above 25kohms.

This resistor needs replaced, right?

 

[preston.ezell]

So I got a stable reading. Seems the a side 150kohm resistor is reading 55kohms max.

 

[preston.ezell]

I guess I need replacement parts for my small board. How do I go about ordering these?

 

[Paul Birkeland]

Woah, slow down a little.  A 55K resistor would actually work fine there. There's also not really a failure mode to kill that part.

In the photos you posted of the build without the C4S board, there is what looks to be some metal material between pin A5 and pin A6.  If those pins touch, you'll get 0V at terminal 1.