Time Pilot 84 Repair Logs

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Repairer: Paul Swan

BOARD NO: 0128
GAME: Time Pilot 84
MANUFACTURER: Konami
DATE: 1984
HARNESS: KONAMI-S

SYMPTOM (05/10/96)



Screen fills with coloured blocks and then clears to a black horizontal bar two thirds up on a white background before resetting and repeating.

SOLUTION



This game uses twin 6809E CPU's, at H12 and F12. The F12 CPU was substantially hotter than the H12 CPU, though changing it did not alleviate this or fix the game. Using a logic probe to inspect the two processors revealed that the H12 CPU was running but the F12 one was not - all address, data and control lines were static with only the Q and E clock pins active. The reset signal was pulsing, consistent with watchdog expiry. The halt and hold signals were inactive. Examining the F12 CPU signals with an oscilloscope suggested that the E input clock was at least half the amplitude of the Q clock, and further measurement gave it a logic low of 1.5V and a logic high of 3V. Using a pulse injector (400pps) on the E pin caused activity on the address/data bus confirming that the CPU wasn't seeing the E clock. Tracing this signal back via a 1K pullup to it's source at pin 6 of F13, an odd coloured ceramic EL74LS04, and checking the input at pin 5 suggested the inverter was at fault (since the input was a full level signal). Changing the F13 LS04 fixed the game.



Repairer: channelmaniac

Symptom: Burnt edge connector

Board had burnt edge connector contacts for the +5v and ground connections. Removed the bad traces and laid down new ones with copper tape. Tested.