leader 8102

I have an oscilloscope, Leader 8102, with faulty Y preamps. The faults are in the variable gain circuits, on small daughter boards. These boards contain 8 pin DIL chips, one each, with the identification removed. The boards have further been dipped in black dippininnin to obscure any trace of identification that may be left. Both the chips are faulty, gain is now at mimimum all the time. Any idea what the chips are, where I might obtain a couple, whether its worth the trouble?

I have a hunch they would be op amps. Check the power pins and associated parts to see if they are dual or single units and replace with a cheap NE5534/2 and see if it works. If it does replace with high speed low noise device.
Failing that you will need a service manual.
Good luck.