Losing my mind debugging this EA Tremolo!

[superferrite]

I have the old Torchy layout of the ROG-modded EA trem, with the flashing LED mod, and I am only getting a nice Mosfet boost.  No tremolo, no flash on the LED, no oscillations of any kind.

Here are the voltages:
Q1(BS170)
D4.98v
G1.71v
S1.27v

Q2 (J201) and Q3 (2n5089) are all at zero volts, maybe with a slight .01-.02v at the collector of Q3
They have all been in circuits before and have proven themselves.

I know it is somewhere around Q2.   I even made my first audio probe, but it is proving to be more difficult to use than I would have assumed.
Any thoughts?
I built this circuit with ANOTHER vero layout and had the same result.  YES, I guess I reused some components!
I'll have to check each resistor with some help...

[hab]

I built this a few years back from the same layout I think. I found that the flashing indicator LED was drawn the wrong way. Check out if this is the case with yours too.

[superferrite]

No, the layout seems fine.  Ugh.   Going cross-eyed...

[ode2no1]

i bought a pcb of the ea trem from general guitar gadgets a few years ago and for some reason i couldn't get that to work. basically yeah, i got a boost, but nothing else.

[LucifersTrip]

Did you breadboard it first to see if it worked?    closeup pics may help someone spot an error.

not much info given, but with Q2/3 all zero volts, there's most likely a missing/shorted or bad connection/component

at least check to see if you have any voltage anywhere after Q1

[superferrite]

If the 250k rate pot was bad could this have a similar effect?  I think that may be a culprit, but all the resistors are fine.  Can't check the capacitors (they were all pretty new) and I replaced an electrolytic that may have been at fault.

Nope, didn't breadboard it... 
My fault, I know.

[Mark Hammer]

The J201.  As I regularly remind folks, even though they only have 3 pins, there are 827 ways to get the pinout of a FET wrong.  verify that the pinout you THINK it has is the actual pinout for the specific brand of J201 you are using.  Set the LFO for the slowest possible rate and measure what you believe to be the drain-source resistance.  It should be changing.

[superferrite]

I'll try and goof with it, but the little "F" is likely Fairchild, and I got the pinouts correct, I think.  Thanks!

[R.G.]

I have the old Torchy layout of the ROG-modded EA trem, with the flashing LED mod,

Do you have a link to the layout and schematic?

[lonewolf]

does the led light up? I recently built a easy-vibe..when I turned it on it worked but no oscillation.led's did not flash.after 6 hours looking thru a jewelers magnifier,it was a short killing the circuit..was very hard to see...I would check continuity with a ohm meter..polarity,etc. I never had any luck with an audio probe..

[superferrite]

LED does NOT light up.  NOT GIVING UP YET!!! 
Taking another Tylenol, though!
The schematic is at ROG:
http://www.home-wrecker.com/eatremolo.html

Here's the layout.  Very hard to come by these days, I understand:

[Mark Hammer]

You know, if you had somehow fried the LED during the process of testing it out (e.g., on a fresh 9v battery without current limiting resistor) to find out which lead goes where, that LED would now be an open circuit between the V+ source and the collector of the transistor on which the entire LFO depends.  Bum LED = no LFO = no change in gain of BS170 = no tremolo.

[superferrite]

a=HA!
Checking now...

[lonewolf]

you should be able to jump the connection at the led points to see if it will work...if you used  the mosfet trans be careful..they will blow at the drop of a hat..very static sensitive....I avoid them or socket them...(I am socket crazy)

[superferrite]

It was wired backwards, but I have to redo some other connections that got jostled loose as well.
Stay tuned...

[superferrite]

Okay, now the boost doesn't work.  I am going to take it apart.

If anyone can suggest a tremolo with a flashing LED, i'm game!

[Crowella]

Another EA Tremolo   

Replace the LED and J201, making sure they are both the right way according to the datasheets. If you are still having problems, I would be checking for any wiring, trace or solder errors. Are you sure you have set the trimpot correctly also?