Shin-ei FY-2 Fuzz Problem-Need help, PLEASE

[bdrobik]

Still trying to debug my second build....going on 1 week of headaches. I have learned alot searching/researching for the solution but now I am going to go crazy!
I am using Dragonfly's layout on vero
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album18/album144/SHIN_EI_FY2_001.jpg.html

I can get a bypassed signal, that is all.
The only modification to this layout is that I am using a 1.5M resistor in place of the 1.2M resistor near Q2.
My readings are as follows:
Q1
C:2.18
B:0.59
E:0.0

Q2
C:9.03
B:7.89
E:0.0

Yes I have tried all the debugging help pages and suggestions I can find. Like I said I am going nuts trying to figure this one out. Can someone please help? Can it be a bad part? Or a bad (inexperienced) builder?

[bdrobik]

Also I am using 2N5088 as the transistors.

[GREEN FUZ]

First off, forgive me if any of this sounds patronising but I`m presuming you`re a novice builder.

Rest assured the layout is fine as it has been confirmed to work by previous builders. Taking that as given there is a chance one or more of your components is faulty. More likely though is you`ve made an error somewhere.

Classic mistakes include

Misorientating transistors:check the pinouts. Same applies to any polarised components; capacitors, diodes, LEDs.
Inadvertant shorts: Check for solder bridges.
Offboard wiring: Check input/output wiring, switch and control leads.


When you`ve done that and still haven`t found the fault, do it again. The most common mistake is to convince yourself you`ve done everything right therefore there must be a problem with the components/layout etc.

Take a deep breath and look again taking a cool methodical approach. Good luck.

[Sir H C]

Something is majorly wrong with Q2, 7v on the base and 0 on the emitter is 10x what should be *possible* for said transistor.  Look at either the base biasing circuitry, or given that the collector is at 9v, I think the emitter is not soldered to ground correctly.

[Dragonfly]

Most common issue with beginners using vero...

They dont know that the little red squares with the dot in the middle mean "cut the copper traces here". Its common to miss a cut, or put it in the wrong place.

Did you do that ?

Second most common problem....

Solder bridges...tiny pieces of solder the connect 2 strips..sometimes you need a magnifying glass to see them.

Third most common...

transistors oriented incorrectly

Fourth most common.....

Ground not connected properly

Fifth most common....

using the wrong value resistor somewhere in the circuit.


Check those things....

As mentioned, Q2 is way off...