Maestro FZ-1A

[Quackzed]

cool! i'm always most suspicious of anything that moves, if it can move it can break... also why i recommended wiggling the input cable in the jack... old jacks can get worn etc... pots can too.. they move...
onward and upward!!

[Riinehart]

ha -- yes! happy to have at least one mystery solved!

[duck_arse]

I'm surprised nobody has responded to this yet. I was hoping someone would so I could learn from a more experienced member what the first few steps might be...

yer doing an excellent job so far.

riinehart, just for me, take the battery out. put yr black lead to the shield of the co-ax I can see in yer pic and measure the resistance between there and the sleeve of the jack. then measure the resistance to each battery clip. what results.

[Quackzed]

something i just learned... you probably know this BUT... the jack you plug a cable into is the output, and goes to the amp. the wired cable coming out of the box goes to your guitar. i would have assumed the wired cable went to the amp, but it's the other way around...just figured i'd point this out, having just learned this myself...

[Riinehart]

Thank you guys -- so happy to finally be learning some of these things.

Quackzed -- yes, fortunately I learned that strange fact about this pedal long ago, and everything is connected correctly (though I wish it were something that easy!).

duck_arse -- i'm going to make myself sound stupid here and ask what you mean by the shield of the coax. Also will I be measuring the resistance between the battery clips and the sleeve of the output jack? Or between the battery clips and the shield of the coax? Will give it all a shot tonight when I get home from work and will post results. Thanks again!

[Quackzed]

by shield of the co-ax he means twisted strands of copper wire coming out of the input cable wire. not the smaller inner wire... and i think he wants you to measure resistance between that spot and each battery lead and also the sleeve of the jack. so leave your black probe on the thick twisted copper wires coming from the cable and with the red probe measure the jack sleeve then the + battery terminal then the - battery terminal... with
no battery inserted.

[Riinehart]

Got it -- thanks again, Quackzed!

[Riinehart]

Ok, measured what duck_arse suggested. Here's what I found:

Resistance between coax shield and output jack sleeve: .6 ohms (I notice this seemed to fluctuate a bit, up to 1.5 ohms ... maybe the battery in my meter is getting low? Or could something else cause that?)
Resistance between coax shield and positive battery lead: .6 ohms
Resistance between coax shield and negative battery lead: [no connectivity/no reading]

Any thoughts?

Thanks again.

[Quackzed]

[Quackzed]

hope you wont mind if i reply to these questions duck_arse. , just trying to keep pluggin away!   feel free to chime in with anything i missed or messed up  

Resistance between coax shield and output jack sleeve: .6 ohms (I notice this seemed to fluctuate a bit, up to 1.5 ohms ... maybe the battery in my meter is getting low? Or could something else cause that?

the out jack shield is connected to ground and the coax shield of input wire is connected to ground, you cant see it on the schem but you measured .6 or 1.5 ohms so they are both connected to ground. a resistance of a few ohms or even 10 or 20 ohms can be considered 0 ohms, a little bouncing around by the meter is expected, nothing to worry over. compared to 470,000 ohms or even 10,000 ohms a a reading of 1 ohm or 10 ohms is relatively no resistance... good.

Resistance between coax shield and positive battery lead: .6 ohms

same here, the + side of the battery is supposed to be grounded and a reading of less than an ohm resistance can be considered directly connected to ground ... good.

Resistance between coax shield and negative battery lead: [no connectivity/no reading]

the negative of the battery has a few paths to ground, but most of em are blocked by caps, so they wont read as a resistance... the only path where the - battery lead CAN get to ground through resistors only is through that 470k ---2k2---22k--- path.(theres a fork at the fuzz pot, but thats just another resistance to ground so dont worry about that) so i'll bet if you crank up your meter to read high resistance, if it has settings for ohms set it to a high resistance setting close to 500k and you should get a reading of @ 500k resistance... a little above or below is good, resistors arent exact, they're within usually 10% of their marked value... if so good!!
next you can go around to all the resistors and measure 'em.one probe on each side of each resistor, just check em to make sure that they read close to the value they're supposed to... set the meter to the appropriate ohm setting then probe em-- and as a bonus you'll get acquainted with your meter, it will serve you well!!! just dont tell anyone you know how to use it or all your weekends will be ruined with O.P.P (other peoples projects )

[Quackzed]

oh yeah, do another transistor voltage reading now that you sorted out the shorting battery leads...
actually do this before you go and measure the resistors...

[duck_arse]

quack.

quackzed - that circuit with the voltages is extremly confusing. is the red dot the red probe, and the black lead is moving? and you're getting (+)'s above and (-)'s below? bad form, old sport!

another something I thought was to measure from the plug sleeve back to the circuit ground, as cable that old (if original) might be shot. and like quack is about to say I was going to say, measure the resistance from the minus terminal of the battery clip to each collector, then the resistance from ground to each emitter. this thing will be so resistance measured by the time we're finished.

I'd better get some Ge's on the bb, see what volts pop-up. I don't think those collectors, with respect to ground, should show full/more than indicated supply V.

[Quackzed]

oops, yeah, disregard the dodts/voltages. it's just the schematic that had been posted on page 1,and doesn't reflect the latest readings or anything. sorry bout the confusion i agree the red dots/voltages are confusing. ive just been ignoring the dots and notes and using the underlying schematic... just re-posted it to not have to keep flipping back to the first page of this thread... probably should have  posted a schem without the added stuff...oh well just ignore the notes/dots...
 

[Riinehart]

Can't thank you guys enough. Should have some time tonight to poke around and get all the new measurements.

[Riinehart]

Ok, some new measurements.

Resistance between plug sleeve and circuit ground - .4 ohms (the cable was replaced a few years ago -- not the old original one).

Resistance between minus terminal and each collector - I'm not getting a reading on any of these. Is that normal?

Resistance from ground to ...

Q1E - 5.2k
Q2E - .4
Q3E - .5

Also, new voltage measurements at each of the transistor legs:

Q1C: -1.3
Q1B: -.6
Q1E: -.35

Q2C: -.96
Q2B: -.05
Q2E: 0

Q3C: -1.24
Q3B: -.01
Q3E: 0

(Q3C, which was previously -1.8v, is now back down below the battery voltage. So perhaps that was due to the short during the last reading.)

Any thoughts? Many thanks again!!

[duck_arse]

well, now, that ain't right. looking at the circuit, you can see the (-) of the battery [clip] connects hard to Q1-C, and via 10k each to Q2//Q3-C's. so either your supply volts is missing, or ........ no, it shouldn't be the jack plug, because that switches battery/ground, doesn't? and Q1-E should show 10k to ground, no?

I hadda go on the bb tonight, and got Q2 and Q3 volts similar to yours. Q1 I'm not sure about. it might be time to do the "search for audio probe" that we so often recommend.

[Quackzed]

yeah, agreed,resistances: q1's base shouldn't be at or near ground, and its emitter should read @ 10k... are you sure your guitar cable isn't shot? ... take a close look under q1, check that no wires are touching that shouldn't be, or arent connected through q1's case... also maybee clean between the battery clip pad and the pad under q1...looks like  something is connecting q1's base and emitter to ground...

[Riinehart]

hey guys. sorry for the delay, just got back from work. thanks so much again for your thoughts on this.

unfortunately i'm a little confused. you probably already know this, but just to clarify and make sure, the first set of measurements i wrote in that post was for resistance to each emitter. the second set was voltage measurements at each leg of each transistor, as quackzed suggested i remeasure them now that the battery short is no longer happening.

are you both saying that, according to the schematic, there should be 10k ohms resistance between Q1E and ground, and, since there is only 5.2k, it must be connecting to ground somehow? i checked the color code of the resistor (3 bands, brown/black/orange) and it should be 10k. but i'm too dumb to follow exactly how the wiring connects compared to the actual schematic.

do any of the other numbers seem out of whack?

i've checked over and over again that nothing is touching that could possibly connect Q1 to ground. have also checked the cable and all is well. and again, signal is perfect with pedal switched off.

would there be any benefit to resoldering the junctions on the board?

i also started learning about how to make an audio probe and am excited to try working with that. i should have it set up by tonight or tomorrow.

[Quackzed]

oops.  i ass-umed the resistance readings were for q1 c b e ... my brain and or my eyes must have been crossed. still , between q1's emitter and ground should be @10k... this might be a good clue though. try checking resistance between q1's emitter and ground again, this time with the fuzz pot all the way down, then again with the fuzz pot all the way up... if you get @ 6k one way and @ 2k the other way, then i think we've got our killer!!! The 1uf cap off of q1's emitter in the library with the candlestick!

[Riinehart]

no problem at all, thanks for clarifying!

not much fluctuation when i turn the attack knob. goes from around 5.12k to around 5.29k.