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Projects => Tech Help - Projects Page => Topic started by: Loads_of_chodes on March 21, 2013, 08:32:50 PM

Title: Chunk Chunk biasing 0.00 read on everything?
Post by: Loads_of_chodes on March 21, 2013, 08:32:50 PM
What's wrong? i can't get a reading on any of the bias points.
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: madbean on March 21, 2013, 09:42:22 PM
Seems likely that you are not getting power to the PCB. Are you reading 9v on the 9v pad? What about at R19 and R20 (the VB and VA supplies).
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: Loads_of_chodes on March 21, 2013, 11:53:43 PM
Nothing. The battery is fine, the connector is fine, but no reading.
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: hammerheadmusicman on March 22, 2013, 12:27:12 AM
Any solder bridges around the 9v pad? Especially to ground..
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: gtr2 on March 22, 2013, 12:36:16 AM
Could you be a little more specific.

Where do you have no reading?

9v pad?

R19?

Etc.
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: Loads_of_chodes on March 22, 2013, 01:21:09 AM
I just rechecked for solder bridges and there are none to be found. I'm reading zero on the 9v pad, r19, and r20.
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: Loads_of_chodes on March 22, 2013, 02:12:48 AM
Also. Pass through works fine. when I flick it on and play I get nothing, but if i turn all the pots (on the pedal) all the way up and strum my strings with a bit o' force I get a little bit of super fuzzy sound from my amp. I can hear different pitches, so it's not just feedback.
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: madbean on March 22, 2013, 02:29:02 AM
Well, if you are reading 0v on the 9v pad then it is possible you have connected the power incorrectly. Can we see some pics of the build, please?
Title: Re: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: stevie1556 on March 22, 2013, 02:47:19 AM
You say you're using a battery, and that turned out to be the cause of my problem a couple of days ago, so you may or may not have the same problem I did.

I built the Egghead, and to test it I connected a 9V battery to a connector that has a 2.1mm plug on it to plug into the power jack (I've decided not to use batteries in my pedals). Had power at the battery, plug, jack, but nothing at the board, checked the wire with a multimeter and it was fine. Tried another battery, same thing. Both the batteries were brand new. After a lot of head scratching, I got my power supply out the car, tried it with that and it worked fine. Don't know if that is any help, but hopefully it is.

Sent from my thumbs using Tapatalk!
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: Loads_of_chodes on March 26, 2013, 02:41:56 PM
Sorry about the wait, I've been busy with work most of the weekend. I picked up a power jack and a 9v plug, wired it all up, checked my connections, and still nothing. I'm in between classes right now but I'll put some pictures up once I get home.
Title: Re: Chunk Chunk biasing 0.00 read on everything?
Post by: gtr2 on March 27, 2013, 02:18:03 AM
Pics would be great!