Removing Charge Pump for debug

[captntasty]

I've just completed a FSH1 build and as I feared from the outset it doesn't work.  Before I debug anything I have to solve the power supply problem.  Rather than fry another MAX1044 (it gets VERY HOT) I'm looking to remove the charge pump from the circuit and implement a 2x9V battery setup.  I'd rather fry a few batteries than the 1044 - I only have a few.  I've searched for posts and found someone with the problem of the 1044 getting hot but it was in the process of Tonda's layout debug and was solved by switching the 10uf cap around - Steve R's layout has the cap oriented correctly  My question is can I remove the charge pump from this layout and if so where do I insert the 2x9V bat into the circuit?

Here's the layout from Steve R. I'm using:

http://ustomp.com/index.html?menu=2&section=6

I'm thinking the battery leads go on the pads to either side of the 100k trimmer but it would seem that something in the 8 pins of the 1044 footprint needs to be jumpered to complete the circuit.  I'm at a loss as to which though.

Any ideas?
signed Please Help Because This Effect is so Freakin' Awesome

[petemoore]

  For +/- 9V usage with MAX1044
  Pin 8 is 9V+, Pin 3 is Gnd, Pin 5 is -9v...
  two batteries...seriesed...
  a + and a - get connected [one from each battery], this becomes ground,
  and leaves a + and a - from the seriesed battery pair which can supply the _/- Voltages related to where pins 8/5 on Max hooked up, I believe you should pull the chip or V supply connections to the chip when substituting batteries for supply.
  Here's the GEO Diagram for +/- 9V supply ala 'MAX'..
  http://www.geofex.com/

[captntasty]

Hmmm... I'm racking my brain trying to figure out how to change the power supply and account for any internal connections in the 1044 that are necessary and just confusing myself.  So, another question - what would make the 1044 overheat and/or would incorrect pinouts on transistors relative to the layout account for the overheating?  Again, I may have confused myself viewing different layouts and schematics where certain trannys were subbed and pinouts are reversed etc.  There are so many places I may have screwed up that I can't retrace it - serious confusion and frustration.  Which angle do I approach it from?

[petemoore]

  If you socketted that chip you can just pull it out, then connect 1 red '+' from the first battery clip, 1 black '-' from the second battery clip, connect these to circuit ground.
  You will have one red and one black wire left, connect the black wire [more exactly which wire connects to a 'battery - pole' to -9v.
  Connect the last battery clip wire [red I think, I know which ever one connects to a battery's +] to 9V+.
  However the first test I'd make is checking for NON continuity between Gnd and -9v, and also non continuity between Gnd. and V+. Might as well check for non continuity between -9v and +9v while you're at it.

[captntasty]

Thanks for the help pete...  I had no luck with the battery setup - some really weird things were happening.  The led would light with only one battery and the other would start to toast when connected.  I'm working on a project and need the sample/hold sound in a few days.  I also etched the tonepad version and will give that a shot and if that doesn't work I'll try ggg maybe - sort of a quick shotgun approach.  If none work out of the gate I'll have to grab a Line6 FM-4  as that has an Oberheim VCF model - then unload it and get back to a diy FSH/VCF when I have more time.  Again, thanks for walking me through it - now I know more about bipolar power supply than I did!

[petemoore]

The led would light with only one battery and the other would start to toast when connected.
  However the first test I'd make is checking for NON continuity between Gnd and -9v, and also *non continuity between Gnd. and V+.
  This test has prevented hot batteries. Hot battery is a frying one.
  Another test I've done is frequently feel if a battery is generating heat for a minute, so that I can prevent further damage by quickly disconnecting it.
  'Finding the problem' is easy, finding the solution...is a more involved matter, of visually isolating where the short is.
  Because a DMM only shows only whether a connection is made or not [the finding] but doesn't indicate What route the unwanted connection travels [the solution], so it can be eliminated, it becomes a visual/tracing/mapping thing.
  For that I recommend a high intensity close in light, I use 25w+ quartz focused ( lens, anyway lotsa light helps, and magnifying glass.

[ustompsteve]

I would check for a solder bridge. It sounds like you might have a short circuit somewhere.

--steve

[captntasty]

Absolutely - I'm going to come back to this one as it is a more compact board.  I'm just working on a tight schedule and don't have time right now to really dig into it.  I did a cursory inspection for bridges and nothing obvious.