Sega Games (Other Arcade)

[channelmaniac]

Model: Naomi
Symptom: Missing audio on right channel

Replaced burnt 510 ohm surface mount resistor at R333S and tested.

[channelmaniac]

Model: Pengo
Symptom: Dead

Board was in a bulk buy and had been scavenged for parts.

Replaced missing 74LS04 and 74LS138 ICs. Board had no clock. Replaced 74LS368 at IC6. No change. Examined clock circuitry closely and saw a hairline crack in R17. Replaced R17 and board tried to boot. Cleaned EPROM legs and board booted, but had graphics problems.

Moving graphics were jerky in nature and backgrounds and text were flipped from the direction the player sprites were playing, similar to a flipped screen in cocktail mode, until after the first round of attract mode finished then were correctly oriented. Repaired 2 gouged traces, one going to an input to a 7489 Bipolar RAM, to fix the jerking graphics. The FLIP signal coming from the 74LS259 at IC 27 was improper on power up and corrected after the first round of attract mode. Replaced the IC and tested.

[channelmaniac]

Model: Chihiro (House of the Dead III)
Symptom: Error 2: Mainboard Error

This system is a Microsoft XBox system with a Sega adapter board attached and a standard Naomi Network DIMM board and GD-ROM plugged in. The Sega adapter board had the same type of leaking .1F supercap that the Naomi 1 systems have. (Unsure on Naomi 2 as I haven't had one on the bench yet.)

Also, the Xbox system it's based off of has a 2.5v 1F supercap over on the front edge of the board. It leaks too and will corrode traces.

You MUST remove the caps, clean up the electrolyte leakage, and replace the caps. Check ANY and ALL traces around the .1F cap on the Naomi adapter board. Patch any damaged traces. Be careful as there is one trace that goes under a tiny 8 pin chip to a pin on the opposite corner and not straight up the side of that chip like it looks.

Patched 1 trace, replaced the supercaps, and tested.

[channelmaniac]

Model: Naomi GD-ROM
Symptom: Will not read discs

Controller board had a smoked IC chip. Replaced the Toshiba TC9450AF IC with one from a donor board. Tested.

[channelmaniac]

Model: Naomi GD-ROM
Symptom: Very noisy when seeking

Replaced laser head motor/gear and tested. Gear had cracked and spread far enough apart that it was causing the gears to click.

[channelmaniac]

Model: Naomi GD-ROM
Symptom: Will not read discs

Replaced laser assembly with one from a physically damaged donor drive. Tested.

[channelmaniac]

Model: Sega Naomi
Symptom: RAM Error

RAM Error: U29 bad

Removed leaking supercap, the 8 pin EEPROM, and the 42 pin BIOS and socket. Cleaned electrolyte from the board and jumpered 2 traces damaged by the leaking supercap. Replaced the 8 pin socket for the EEPROM and reinstalled the IC. Reinstalled the 42 pin socket and the BIOS chip. Reset the Backup RAM and tested.

[channelmaniac]

Model: NAOMI
Symptom: Dead

Both the GPU and case fan were seized. Replaced both fans and tested. Replaced leaking memory supercap and re-tested.

NOTE: The NAOMI will NOT boot if the GPU fan is turning slow or not at all.

[channelmaniac]

Model: Laser Ghost (System 18)
Symptom: No sync, Crackled sound

Cleaned board, cleaned edge connector with a fiberglass pencil, and replaced 2 physically damaged caps. Tested.

[channelmaniac]

Model: ST-V
Symptom: Dead

Built a replacement shorting plug to go into connector CN5. Game then booted with a cartridge error. Ran Factory Tests on Slave CPU and it passed. Disassembled the Die Hard cartridge, cleaned the edge connector, reassembled, and tested.

[channelmaniac]

Model: ST-V
Symptom: Dead

Resoldered the 2 SH-2 CPUs. Tested.

[channelmaniac]

Model: ST-V
Tip: Building a shorting connector for CN5

The board will not boot without this shorting connector or a daughterboard plugged into CN5. Take a female jack that fits the connector (Same kind as on a Playchoice-10 motherboard) and built is as follows:

Cut and remove all soldertail pins from row C
Cut and remove pins A1 through A5
Cut and remove pins B1 through B5
Cut and remove pins A27 and B27
Bend pin A6 to touch B6, A7 to touch B7, A8 to touch A8, and so on for all the remaining pins on rows A and B.
Solder pin A6 to B6, A7 to B7, A8 to B8, and so on for all the remaining pins on rows A and B.