PCB Repair Logs Millipede
Millipede
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| Manufacturer | Atari |
|---|---|
| Year | 1982 |
| PCB Image | Reserved |
| Pin Out | Millipede |
Repairer: Arcade King
Forum Thread: Millipede PCB Repair
Original Atari Millipede. Gavin got this board from the states for me.
Beginning Notes:
You need the +22 volts for video to work.
You need the +10.3 volts for the reset circuit to work.
The -22 is for the earom to save the high scores.
Usisng a modern standard Arcade PSU (+5,+12 and -5) use the +12 volts across for the +22 and +10.3 volts.
I originally had +5 going to the 10.3 which leads to a TL082 and this is not enough. I ****ed around for ages wondering why there was no video and the CPU was not running. I disabled the reset circuit by lifting a resistor to make the reset line go high. This made the board start watchdogging. Adding 12V to the line got the circuit running properly.
When first turning on the board all you see is a white flash then a dead blank screen. I later found out this was because I had wired the RGB at the wrong end of the connector(dickhead me) there still would have been nothing because of the fried Hsync circuit.
Found a 259 @ 12E that was super heating with outputs dead. Replaced it. I found there was no Hsync. Fix: Bad 74ls74@H6 and bad 74ls07@2D pin 1 ans 2 of the 07 were shorted.
The board is showing a heap of sprites and garbage on the screen. The cpu is watchdogging. Turns out a graphic rom was swapped for a program rom. Kicking myself I didn't notice sooner
