Check to make sure diodes CR1 and CR4 are not shorted, and are not in backwards (if you did remove or replace them at any point).
Make sure none of the caps are shorted.
Make sure you have a good mica or silicone insulator on the bottlecap transistor, and that you didn't accidentally put too much solder on the 2N3055 pins, such that they are shorting to the heatsink, under the heatsink. If in doubt, pull and re-solder it, and use as little solder as possible.
If you've replaced Q1 (LM305), Q2 (TIP32), and the 2N3055 with known good parts, then there's something else simple that is being missed, as those are the 3 active components that pretty much make up the 5V circuit.
Where did you get your parts? It's not a bad idea to suspect new parts as possibly being bad, depending on where you got them. It doesn't happen often, but it happens enough that you should always leave room for it being a possibility, when you're stumped. The TIP32 and 2N3055 are easy to check *out of circuit*, with a DMM. The LM305, not so much. (Or at least I don't know of a simple way to test it, so I just swap them out if they are suspect.)
Other than that, check all of your work, and make sure there are no shorts between traces or pins, and make sure none of the leads from the components are bent over and touching each other, on the solder side. (I always trim any that are sticking up too far, what could get bent over and touch something they shouldn't.) To look for shorts, hold the board up to a bright light source, and look through the PCB. Any shorts between traces will become much more visible.
You can also check continuity of the pins on each of the Molex connectors, to make sure they all are connected to the PCB. I had one AR recently that threw me for a loop, until I found that one of the pins had broken inside the connector, so it wasn't making contact.
Look for other broken solder joints, especially where traces connect to pins, like on the TIP32. You can get hairline cracks where the trace meets the solder blob of the pin sometimes, and not see them. Check everything with your DMM.
As a last resort, you can try pulling the audio amps (Q5 and Q7), and seeing if that makes any difference. I recall seeing one AR where a short in one of the amps was affecting the +5V, but I don't remember exactly how it was doing so, as I thought the audio was supposed to be independent from the +5, but apparently there's some way they can become coupled, via a bad TDA2002.