A screw had come loose from the flash circuit board and was rattling around above the board. It would occasionally short something out and prevent the flash from working as well.
Also, Holga's come with an aperture switch, but the hole in the arm that swings behind the lens when you flip the switch is bigger than the existing maximum aperture, so it doesn't do anything. It's up to you, the Holga owner, to modify this to actually do something. The size of your new aperture is up to you.
Step 1: Expose Shutter/lens Assmbly Screws.
Step 2: Remove Lens and Shutter Assembly.
Step 3: Remove the Top
Step 4: The Loose Screw
Step 5: Remove Shutter From Housing
Step 6: Prepare the New Aperture
Step 7: Install the New Aperture
Step 8: Reassemble
If you have removed the lens, be sure that it is re-threaded correctly. When it's fully tightened, the mountain icon should be aligned with the focus line. Adjust the focus away from either extreme and then re-install the lens fixing screw.
The top is a bit tricky to get back on, as the flash switch extension is just a loose piece. I was able to get the top back on without too much trouble by first place the flash switch extension in place, and 'switched' to match the setting of the switch on the flash board. Then, while holding the top with the back side facing down so the switch extension does not fall out, insert the top of the camera body into the housing top. Re-install the three screws that secure the top.
Then, re-install the shutter plate, and install the two screws the secure it.
Solder the flash trigger wires back to the switch. There is no polarity to be concerned about here; either wire can go to either contact.
Align the shutter/lens asembly on the body, and re-install the two screws that secure it.
Step 9: Inspect Your Work
Here, I have reinstalled the batteries, the spring board, and the image frame With the shutter in 'B' mode and while holding down the shutter release, look through the lens from the back and operate the aperture switch. You should be able to clearly see the aperture arm with the new aperture plate swing in and out of place.
And that's it! Load up some expired 120 film and get out there shoot something!
Thanks for reading this far, and I hope my first instructable was helpful for you.