Have you ever admitted defeat with a DIY project?

[mikeyB]

Just seen your 2nd post re the low level constant signal - does it sound thin?(all top end no bass) - this is the problem i had until i sorted out the tranny connections!!

 

[usekgb]

I have a Ramsa console that would mute randomly.  I tried all sorts of things, including hitting the top of it (which actually worked!).  What it finally came to was a cold solder joint on the bottom of the power supply.  A touch of solder, and everything was good to go.  Never give up, and try approaching the problem from different angles.

 

[nielsk]

A master tech once taught me, 1st thing to know about troubleshooting is who to call for help when you are stumped! (Call on all of us, that's what we are hear for...right?)
2nd rule, if it takes more than an hour to figure out, you are loosing money. If this a job, that is the point when you go from component level to board level, then to unit replacement (as in, walk away).
If this is a hobby you keep at it until one of you surrenders, akin to interrogation by the KGB.
As to your problem, how about removing components from the equation?  Try the signal generator straight to the transformer, taking the attenuator and connector out of the circuit. Add things in one at a time to find the problem.
Are you using the transformer PCB? Try it without (those PCBs are a little troublesome, by having so many footprints they can be confusing and need some jumpers not shown for certain transformers) by wiring straight to the transformer.
You can also swap these sections out with the known working unit one a a time...

 

[JohnRoberts]

A master tech once taught me, 1st thing to know about troubleshooting is who to call for help when you are stumped!

A good idea IF you have somebody to call....

2nd rule, if it takes more than an hour to figure out, you are loosing money.

Unless you are paying yourself nothing, and could not earn money by spending the time doing something more productive.

If this a job, that is the point when you go from component level to board level, then to unit replacement (as in, walk away).
If this is a hobby you keep at it until one of you surrenders, akin to interrogation by the KGB.

Divide and conquer. troubleshooting a proved, known design is relatively linear and methodical,  compared to trouble shooting a novel design that never worked, where the design is also a variable. 

As to your problem, how about removing components from the equation?  Try the signal generator straight to the transformer, taking the attenuator and connector out of the circuit. Add things in one at a time to find the problem.

Divide and conquer.. if A works by itself and B works by itself, A+B should work.

Are you using the transformer PCB? Try it without (those PCBs are a little troublesome, by having so many footprints they can be confusing and need some jumpers not shown for certain transformers) by wiring straight to the transformer.
You can also swap these sections out with the known working unit one a a time...

Good luck...

JR

 

[kato]

While "sleeping on it" is always good advice, you've clearly done that many times already.    But yeah, put it away when you're hot and frustrated and come back later with a fresh head.

Writing for help, which you're doing in this thread, is another good technique. Forcing your brain to "think with words" that others can understand clarifies your thinking as you anticipate your recipients' reactions.

Third: build an audio probe and chase it down. You're already in the general vicinity of the fault - most likely a single point of failure you wouldn't normally consider. Could be a broken PCB trace (rarely, but it happens.) It could even be a defective wire between XLR and PCB. The probe lets you have a listen at each point so you can zero in on the culprit. 

"You got these claws and you're staring at these claws and your thinking to yourself, and with these claws you're thinking, "How am I supposed to kill this bunny, how am I supposed to kill this bunny?"

 

[DaveP]

Thomas Alva Edison:-
"I have not failed, I have just found 10,000 ways that don't work"  CJ is dead right!

A book of his life was given to me by an enlightened teacher when I left his class, it set a standard for me I have been chasing all my life.

The "sleep on it" trick really works.  I learned recently that only a small proportion of our brain is involved in maintaining conciousness, problems do get resolved while we sleep.

Last point, once you give up on something it gets easier to do it again until it becomes a pattern for life. RESIST! ;D

best
DaveP

 

[qmp audio]

As said before, take a break, don't think about it in a few days and the answer will come.

Let your subconscious mind work for you.

 

[mobyd]

Sometimes external events conspire to make your efforts absolutely pointless.
I was deeply into a project to motorize the faders on a Presonus Studiolive SL24/4/2 mixer.
Sourced the faders (lovely Alps conductive plastics), fitted them to the desk.
Designed the motor driver PCBs and had them made.
Worked out the ballistics software for the seeking motors.
Analysed the bitstream driving the control panel of the Presonus so I could tell the motors where to go.
------------Then Behringer brought out the X32--------------
It cost chickenfeed  (<$3000)
It did everything I was trying to achieve, and a whole lot more.
But worst of all....It was a far better sounding mixer than the Presonus.
Left with a pile of bits & a slew of half written code.
Won't try that again.
M

 

[livingnote]

and don't forget to pound it to a fine powder with a ten pound mallet so that you can find even the most subtle of mistakes you might have made...makes reassembly a bit more tricky but it's what I would always do when pressed for time. I say would because I don't do this anymore. If my brain doesn't want to naturally flow in the direction of something and I'm up against a block, I no longer attempt to penetrate the issue brute force style anymore.

 

[Che_Guitarra]

This old chestnut - I still haven't solved this issue, but the build has temporarily been benched - i've got a few other projects distracting me now.

 

[livingnote]

An obstacle is an arrow pointing in an unexpected direction that will lead to treasure

</BasharQuote>

 

[JohnRoberts]

Sometimes external events conspire to make your efforts absolutely pointless.
I was deeply into a project to motorize the faders on a Presonus Studiolive SL24/4/2 mixer.
Sourced the faders (lovely Alps conductive plastics), fitted them to the desk.
Designed the motor driver PCBs and had them made.
Worked out the ballistics software for the seeking motors.
Analysed the bitstream driving the control panel of the Presonus so I could tell the motors where to go.
------------Then Behringer brought out the X32--------------
It cost chickenfeed  (<$3000)
It did everything I was trying to achieve, and a whole lot more.
But worst of all....It was a far better sounding mixer than the Presonus.
Left with a pile of bits & a slew of half written code.
Won't try that again.
M

Perhaps you should ask Presonus if they are interested. There still is a hard core of Presonus users that might be interested.

Behringer rolled their own motor-faders to keep the cost down, but that may encourage Alps to drop their price, or come out with a more competitive fader model. I recall Alps coming out with their K-fader in response to the cheap Jung poon dual drill rod fader decades ago.

JR

PS; While not exactly a DIY fail, I recall back in the late '60s trying to repair a kit strobe light that a friend built and he couldn't get to work. I had corrected a few errors and was getting close to strobe action, when I inadvertently discharged a high voltage cap into my hand while holding the strobe. My involuntary muscular reaction, sent the strobe flying in a nice arc, landing on the floor upside down and shattering the strobe lamp. I had to report to my friend that unfortunately it couldn't be fixed. 

 

[buildafriend]

That story made me laugh pretty hard JR. I'm glad you survived the blast!!!

Anyway, I just wanted to post back in here because recently I fixed something right when I thought it had gotten the best of me.  8)

Don't give up guys!! Who's gonna replace the gurus in 30 years? It's going to have to be kids like myself. I'm sure all of the forum stars in here have had a rough time with something at one point or another.

divide and conquer.

 

[JohnRoberts]

divide and conquer.

Some more good advice about troubleshooting. Do not ASSume anything. Or the corollary check everything.

Two weekends ago I helped my 84 YO neighbor with his riding lawnmower that wasn't charging the battery, even though he had replaced a $70 part in the charging circuit.

When I started tracing things out the first thing I noticed was an added start switch jumping across the starter solenoid, that apparently worked, while no doubt causing a voltage drop in series with the starter.

He showed me the shiny new rectifier/regulator (?) block and I was able to see some AC voltage at the input to this block, and some DC after, while voltages seemed low.

But the surprising discovery was that the wire from the charging circuit that is supposed to feed the battery by connecting to the battery side of the starter solenoid, was connected to the starter motor side. Sooo any charging current was just dumping into the starter motor.

We'll see if the charger now tops off the battery but the jumped  starter switch voltage drop does not make it easier to start.

I got a bunch os shrugged shoulders and "I don't knows" when I asked who could have connected the charging wire wrong.

I told him to go to a junk yard and pick up an old car starter solenoid , to get that right. We'll see, spring is coming.

JR