The board gives four flashes but not the fifth, and there is no speech.

Squawk and Talk stops at four flashes

Cause: A bad TMS speech chip U8 or PIA U7, or no -5 V at TP4. The -5 V comes from the GI circuit, so a blown GI fuse also kills sound and speech.

Checks

• Measure TP4 for -5 V and check the GI fuse.
• Swap U7 and U11.

Fix

• Replace the GI fuse, PIA or speech chip.

Systems

• Bally MPU AS-2518-35

Related tips

• Squawk and Talk: distorted sound or hum
• Squawk and Talk test points
• Bench-test a Squawk and Talk board
• The Squawk and Talk test button can lock the board up
• Squawk and Talk supply needs
• Squawk and Talk LED stays on and the board never boots
• Squawk & Talk -61 and Say It Again -81 test points
• Speech too deep, slow and garbled: drifted R9 by the speech chip on Squawk & Talk

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)