Debugging - Ruby

Started by Opencan, September 02, 2007, 04:46:01 PM

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Opencan

My Ruby (from runoffgroove.com) doesn't work, there's no output at all.
Components changed : the MPF102 to a 2n5458 (which I found to have the same pinout) and an alternate 386.

Battery Voltage removed from the clips - 8.4V

Q1
G = 6.03V
S = 5.53V
D = 6.51V

IC1 (or U1)
P1 = 1.62V
P2 = 1.5V
P3 = 0
P4 = 0
P5 = 0.77V
P6 = 6.48V
P7 = 0.45V
P8 = 2.08V

CAN YOU SPOT THE NOT? (too much reaplys)

I just hate to follow diagrams with the suggested layout, i always fail at them -_-
anyhow, thanks for anyone who bothered to read untill here, Ron.

ehofherr

  I would first look at all the wires.  Is everything connected properly?  Start at the input jack and go all the way to the output.  Double check the layout and schematic with your board.  Also look for a ground problem.  It can be very easy to ground out LM386 pin 2.

  I haven't compared the datasheet for the 5458: http://www.fairchildsemi.com/ds/2N/2N5457.pdf and the 102: http://www.fairchildsemi.com/ds/MP%2FMPF102.pdf.
Need help with woodworking?  Just ask.

Opencan

Quote from: ehofherr on September 02, 2007, 07:53:06 PM
  I would first look at all the wires.  Is everything connected properly?  Start at the input jack and go all the way to the output.  Double check the layout and schematic with your board.  Also look for a ground problem.  It can be very easy to ground out LM386 pin 2.

  I haven't compared the datasheet for the 5458: http://www.fairchildsemi.com/ds/2N/2N5457.pdf and the 102: http://www.fairchildsemi.com/ds/MP%2FMPF102.pdf.
The wires seem to be well.
I can't find any ground problem as all connection seem to be fine and I've worked just as the layout did.
Pin 2 isn't grounded. at least I believe so, because thats what my meter showed, but then 2 minutes afterward it started to lose it.
I've triple checked the board before and after installing each components, and twice after completing the board. then 5 times more while searching for possible pinout problems with the FETs and found none. I've also compared the board to an old Ruby I've build a while ago that used to work.
I've already compared the pinout of the FETs and its the same. I've checked for a few MPF102s compared to my 2n5458 (Motorola one)

One more symptom: the IC is getting hot when the battery is connected to the circuit.

Barcode80

there is likely a short between 9v and ground