Loophole problem revisited

[non-reverse]

I started debugging my loophole several weeks back but got sidetracked and just got back to it this evening.  It seems the power regulator is getting really hot no matter how it's oriented in the socket.  When I supply power, I read 9.18 V at whichever lead happens to be in the upper most socket (assuming you're looking at the board as it's laid out in the build documents) The other legs of the transistor will vary in voltage depending how they are oriented. 

I took the power regulator out and I began poking around looking for continuity and found there was continuity between the middle and lower transistor socket (forgive me, I can never keep straight EBC especially since I've flipped this tranny around so much).  Looking at the schematic, I got the impression that there shouldn't be continuity there. 

I removed C17 and C6 in the off chance that they were bad and perhaps were acting as dead shorts to ground but when I pulled them out, there was no continuity through them and there was still continuity between the two lowest pins of the socket. 

Is my thinking completely screwed, am I reading the schematic incorrectly?  It should also be noted that I get signal when it's bypassed and when it's plugged in to power (even with the hot ass regulator) pedal will pass signal and I can increase the volume with the volume knob.  There is no record or playback function which doesn't surprise me. 

I'm really at a loss for where to go here so any help would be appreciated.  I've included a picture in case there is a solder bridge or something I've missed. 

[non-reverse]

Okay, sat down and did more probing and found out that the regulator only overheats if the Dtune switch is on.  looks like the bottom leg of the regulator gets shorted to ground through the 22 ohm resistor near the Dtune switch.  Is that what's supposed to be happening?  If so, why is that regulator getting so darn hot?  About to throw in the towel on this one.

[madbean]

That's what is supposed to happen. The Detune acts as a current sink on the regulator which puts the ISD chip in a semi-failed state which causes the pitch to detune.

Make sure you are testing/probing with the detune off. It only works for 10-15 sec. and then the ISD will stop functioning. However, function returns to normal once you switch off the Detune.

[non-reverse]

Brian,

Thank you so much for the reply. A little more tinkering and I'm able to record and playback AND detune.  When the detune is off, everything is dandy and I've noticed that the detune only works a short time.  What a relief. 

The only problem remaining is that when I record a loop, both LEDs light up.  I've checked my wiring and everything seems to be kosher but I should add that I included the safe switch....does that matter?

[madbean]

I think I failed to show that is the case in the build doc---I only showed one LED lit in the illustration, but it should be both.

So, yours sounds like it working properly.

One thing I will be working on in Loophole 2 is how to make that detune/fail thing work better. I got something mapped out a while ago but nor finished.

[non-reverse]

I had a look at a couple Youtube demos of the Loophole and realized that both the LEDs illuminate in record mode.  So excited to have this up and running, thanks for the help.  I've had a string of failures and it's nice to get something working.  I love your stuff!

Next up, my aristocrat debug. Got a little lab set up at home so I can get good pictures and voltages.  Boom.

Thanks again!