Hello,
I'm repairing this Super Ranger bootleg with same design as original Suna board.
At the beginning there was black screen. Verified missing clock signal because quartz 24mhz was disconnected from one pin.
After replacing it still no signal. Followed traces and came to a 74s04 broken replaced with a 74f04.
Still no signal so traced signals back to a 74s74 replaced with f74. Then I had the clock signal around all the board.0
The faulty TTLs were from National with the two DM code lightning bolts...
The image only showed a vertical stripe on the left, but the game was working from sound and credits and so on.
Replaced the 2 palette 6116 RAM from the game at positions 4 I/K (on the right), also replaced the tile ram at positions 7/8 E (on the center)
and 2 main game rams at positions 10 B/F (All Toshiba TMM2016BP not really reliable despite the other brands).
Removed the 33 ohm resistors between ls169 pin 8, position 7/8F, and pin 21 of the RAM underneath because they were causing some glitches (not shown in another image of the same board).
The "blurry" characters were caused by the 11P EPROM (87) with a oxidized socket replaced.I also replaced the socket next to it because the adjacent resistor array had a shorted to ground pin 3:
I discovered that it was connected to pin 1 of the EPROM to ground.
At first The image appears intact except for the striped text background. As for caracters I don't have an updated pictures but as I said this is fixed and they have pink skin
but then, as the characters move,vertical black stripes appear.
This could be due to buffers 273 or 245 of tile RAMs 7/8 F but I'm still investigating.
Any hint would be appreciated
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I'm repairing this Super Ranger bootleg with same design as original Suna board.
At the beginning there was black screen. Verified missing clock signal because quartz 24mhz was disconnected from one pin.
After replacing it still no signal. Followed traces and came to a 74s04 broken replaced with a 74f04.
Still no signal so traced signals back to a 74s74 replaced with f74. Then I had the clock signal around all the board.0
The faulty TTLs were from National with the two DM code lightning bolts...
The image only showed a vertical stripe on the left, but the game was working from sound and credits and so on.
Replaced the 2 palette 6116 RAM from the game at positions 4 I/K (on the right), also replaced the tile ram at positions 7/8 E (on the center)
and 2 main game rams at positions 10 B/F (All Toshiba TMM2016BP not really reliable despite the other brands).
Removed the 33 ohm resistors between ls169 pin 8, position 7/8F, and pin 21 of the RAM underneath because they were causing some glitches (not shown in another image of the same board).
The "blurry" characters were caused by the 11P EPROM (87) with a oxidized socket replaced.I also replaced the socket next to it because the adjacent resistor array had a shorted to ground pin 3:
I discovered that it was connected to pin 1 of the EPROM to ground.
At first The image appears intact except for the striped text background. As for caracters I don't have an updated pictures but as I said this is fixed and they have pink skin
but then, as the characters move,vertical black stripes appear.
This could be due to buffers 273 or 245 of tile RAMs 7/8 F but I'm still investigating.
Any hint would be appreciated
QuoteReply
ReportEdit