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Title: Amstar Games Post by: channelmaniac on September 16, 2008, 02:02:48 AM Model: Phoenix
Symptom: No video. Whining sound from speakers The board was stored someplace where it got wet & had what looked like leaf residue on it. Cleaned the bottom board and replaced all 12 ROM sockets. Replaced the K1 and K2 EPROMs as they had pins that rusted off at the body. No change. All ICs appeared dead. There was no clock signal. Replaced a bad 7404 IC to fix the clock. Game would boot but had garbage on the screen and would randomly reboot. Replaced 1 74LS244 IC and 1 2114 SRAM ICs that had corroded legs. The rust on the 2114's legs went up the pin into the body of the IC. Played a few games to test the system. Title: Re: Amstar Games Post by: channelmaniac on February 06, 2009, 01:17:59 AM Model: Phoenix
Symptom: Graphics glitch and bad audio Replaced missing sound pot. Board was missing the shooting and explosion sounds. Replaced a bad 4006 IC at IC45. Replaced bad socket on ROM at location IC23 to fix an intermittent graphics glitch and tested board. Title: Re: Amstar Games Post by: channelmaniac on February 07, 2009, 02:24:45 AM Model: Phoenix
Symptom: Dead Logic probe showed the clock signal and video sync signals were present. It also showed no activity on both the address and data busses. Replaced a bad 2114 SRAM IC to fix. Replaced broken sound pot to fix the audio output. Title: Re: Amstar Games Post by: channelmaniac on February 07, 2009, 02:26:12 AM Model: Phoenix
Symptom: Dead. Missing 3 chips and 17 capacitors. Has 2 pulled traces. Obvious trace damage on board - 2 traces were sticking up from the board and there were 2 missing pads on IC17. IC17 was also missing. The CPU socket was partially melted from a soldering iron. Replaced missing IC17. Patched 2 broken traces. Replaced bad CPU socket and replaced the missing 8085 CPU. Replaced broken IC48 on the video board. Replaced 17 missing capacitors and 1 incorrect resistor to fix the sound subsystem. Title: Re: Amstar Games Post by: channelmaniac on February 07, 2009, 02:27:08 AM Model: Phoenix
Symptom: Board sync output is bad Board had some kind of output on the sync pin but it was incorrect. Found that the board was modified. 1 trace was cut and 2 were jumpered. Reset the board back to factory, replaced the broken sound pot, and tested. |