Wavetek 184 sig gen not making any waveform

[Skyfox]

I know this is a long shot but I am completely stumped on this issue.  I've been working on it off and on for 3 years now, unable to find the fault.  I have an old Wavetek 184 signal generator that is not putting out any signal.  A few years ago it was working just fine one day, and dead the next.  With the schematic and an oscilloscope I can't even figure out where the signal would originate on the board, and I can't find any waveform signal anywhere.  The only signals I can find are the sawtooth for the sweep circuit, and the DC offset. 

The faults I have identified were the two opamps in the power supply circuit that make the ±15V lines.  The two lines were about +24 and -5 volts, and replacing the opamps returned those lines to + and - 15V.  I also found a bad opamp in the GCV (generator control voltage?) circuit, so replacing that returned a proportional 0-5V on the GCV out BNC when before it was a flat 0V.  All of the other voltages test good.

The troubleshooting portion of the manual says to try removing one transistor, Q44, to see if the waveform returns, which would indicate a problem in the trigger circuit.  Pulling Q44 made no difference, which the manual says would indicate the problem is in the generator loop.  I don't entirely know what it means by generator loop.  I've pulled and tested every transistor on the main board and power regulator board and they all test good.  IC3 is a transistor array (CA3096AE) and all those transistors test good.  All the electrolytic caps appear to test fine while in circuit, but I can pull them to test out of circuit if that's advised.  IC7 is a SN7400N NAND gate and that tests good (by swapping with a new one that made no difference to the problem).  I don't have a real good way of testing the opamps aside from replacement, and a couple of them are the old metal can packages which I don't have.

If anybody has any ideas on what else I can check, please let me know, and thanks in advance for any help you can provide.  I'd like to fix this thing so I don't have to buy another one but I'm at a total loss and have no idea where I could send it for a professional repair.  Here are the pictures of everything, plus the PDF manual which contains the schematics and such.

[Audiorepair]

In the past, I have had problems with vintage synthesisers that use the CAxxx type of transistors array chips.
Modern versions of these chips will sometimes just not work, but if you sub in a chip made around the same time the equipment was manufactured, it will.

I assume that the original chips had slightly different parameters than those made later, and the synth was designed for the old ones.
This happens in oscillator and resonant filter circuits.

Kind of bizarre, but I ended up buying two or three hundred pounds worth of original old Harris or Intersil (can't remember) ones from a chip broker to solve my problem.  (They all seem to have quite high minimum order values)