Video (9) Horizontal drive (10) Vertical Drive (11). But the trapezoidal area bounded by (UC6, UI6, UG8, UA8), and additionally the ICs UJ6 and UK6 are all video related, and to make signal tracing matters more complicated there are five mystery PALS. An easy step is to remove (one at a time) all socketed PALs and the Video ROM (taking care to ground yourself to prevent ESD), clean the leads if necessary and reinsert to resolve any aging socket contact issues. If you have a scope and cable extensions you can look thru the entire area for marginal levels; everything should be logic levels. UD8, UE8, UF8 are particularly vulnerable to C7 leak corrosion and shorts both to the PC traces and internally into the IC leadframes themselves. If you are a skilled solderer you can cut out these three ICs, remove the lead stubs one at a time and install SMT replacements after carefully inspecting and repairing the traces underneath these particular ICs.

With respect to battery leakage, D1 keeps the normal power from charging the battery, and D2 keeps the backup battery from trying to power the +5 rail when the machine is off. Both are SMT versions of 1N914. If your version of CPU PC board has C12 near the RTC, leakage from this cap can spoil RTC operation and cause several kinds of battery failure if either diode leaks in the reverse direction more than spec.