Thought I'd share the extent of the board refurbishment. Believe it or not, this pin worked fine with no resets. . I had never a reason to pull the boards or looks at them closely....
WMS WPC-3 Power Driver board (No serial number. Prior repair and battery corrosion throughout driver transistor area): Beyond economical repair. !!Still need one of these!! Pm me or Bryan if you have one.
WMS WPC-89 CPU board (No serial number. Extensive prior repairs (NTE parts). Blown logic. Intermittent garbage on display. Inoperative switches. Corroding battery socket (looks to be water damage). Wiring to wrong destination on rear of board. Bad sockets. Broken ASIC socket): 74LS14 IC (U5 -- blown) and 14-pin socket. New 84-pin PLCC socket. New U9 Williams custom ASIC chip (intermittent garbage on display). Replaced game ROM (NOS 27C040 with version 9.4H Twilight Zone game code). Replaced melted U20 IC socket. Replaced NTE chips with OEM -- 74LS374 (U14) and 74LS240 ICs (U15). Corrected incorrect wiring on rear. Fixed open trace and added Kapton tape. Removed damaged IC sockets from U16, U17. 2x LM339 ICs (U16, U17) and 2x 14-pin IC socket. Removed excess flux from prior repairs. Straightened bent pins. 100uf/25v/105c filter capacitor (C31). J210 high temperature power input header. New type 2 battery holder. Removed a small amount of battery corrosion from board surface. Board cleaned up. Two-tier full functional testing
WMS Fliptronic II (SN 53220180432): All fuses removed and checked -- okay. Added missing 100uf/100v/105c capacitor (C2). 100uf/25v/105c (C1) capacitor. Reflow all headers, bridge rectifier and fuse holders. Two-tier full functional testing.
WMS WPC-89 Sound board (SN 53336104986. Capacitors way out of tolerance/drying-out/high ESR): All socketed ICs removed and tested. Sound ROMs (3) removed, internal data verified. U14 and U15 ROMs labeled. LM1875 amplifier and TO-220 Sil-pad. 2x 1uf/35v tantalum capacitors (C46, C47). 22uf/50v/105c, 5x 47uf/25v, 2x 47uf/35v/105c, 100uf/25v/105c and 2x 4700uf/35v/105c capacitors. All headers and fuses reflowed. Fuses removed and checked -- okay. Two-tier full functional testing:
WMS WPC Dot Matrix Display Controller (SN 53336104986 with prior repairs and burning components/traces): Fuses removed and checked -- 2x 3/8 amp slow blow fuses (3/4 amp installed). 2x 150uf/150v axial capacitors. 2x burned traces repaired. 100uf/25v/105c and 3x 0.1uf/250v metal film capacitors. 2x 2n5401, 2x 2n5551, 2x MJE15031 and MJE15031 transistors. 3x TO-220 Sil-pads. 2x 120 ohm 1/2 watt and 4x 47k 1/2 watt resistors. 1N4742A, 1N4759A and 2x 1n4758a zener diodes. 120 ohm 5 watt, 1.8k ohm 5 watt and 4.7k ohm 5 watt ceramic power resistors. Board cleaned-up. Two-tier full functional testing
WMS WPC-8 Driver board (with prior repairs. Clock not working): 2x zero ohm resistors (PW1/3). Reflow headers. Two-tier full functional testing