New Life Games LLC
NLG Users Repair Logs and Other Ramblings. Request your very own topic. Just ask any site staff. => Channelmaniac's Arcadecomponents' Old School Repair Logs => Topic started by: channelmaniac on February 14, 2016, 10:41:25 PM
-
Model: Fairchild Channel F
Symptom: Powers on and off at random
NOTE: The full game console was not brought over... just enough of it was so that it could be powered on and tested.
This was a PITA to chase down. The +5v output would randomly shut off then come back on after about 10 seconds. It would do it more often if the board was sitting on the bench normally. If you stood it up and tilted it slightly over it would stay on longer.
Replaced the bridge rectifier in the +5v power supply section. The power into it was normal but the power output would come and go. As for the board lasting longer when the board was tilted, there are 5 buttons on the game for reset, game select, game start, etc., and they didn't have enough springiness to stay up. In other words, they would stay active as if you pressed the buttons and this caused the game to pull slightly more power from the supply for each button held down. It was just enough to cause the bridge rectifier to drop out.
Board would then display a blank raster of the proper color but all game elements were missing. No borders, no player paddles, no ball, and no score. The 74LS195 latching the RAM output to the video output section was missing all outputs. If the logic probe was placed on the inputs you could see artifacts of the missing elements on the TV. Pin 10 (dot clock signal) was missing. Replaced a 74LS04 in the dot clock circuit but that did not restore the signal. The signal was missing between gates on the 74LS04 and further inspection of the circuit revealed 3 missing 47uh choke coils. Replaced the missing coils and the game would now play properly - if the board was held tilted.
The owner of the game was called and he said there were springs under the buttons and that he had all that hardware. If it weren't for there being springs the 5 switches on the game board would have to be replaced as they would not stay up and deactivated.
-
Model: Mario Party, Nintendo 64 cart
Symptom: Dead
Patched 2 bad traces between the edge connector and the ROM. Tested.
-
Model: Vectrex
Symptom: Distorted images on screen
The vectors were not lining up and the test cart gave distorted screens.
Replaced a 4066 and 4052 IC and a TL082 op-amp. Tested successfully, but button 4 was not working. Cleaned the button membrane and PCB contacts and retested successfully.
-
Model: Sega SG-1000
Symptom: Controller stuck going down
Found an input on a 74LS257 IC that was reading 500 ohms to ground. Replaced that 74LS257 IC and proactively replaced the other as they were both Fujitsu brand ICs. Tested.
-
Model: Sega Genesis
Symptom: Won't boot all games
Replaced physically damaged cartridge connector slot on the main board. Tested.
-
Model: Intellivision (I)
Symtpom: Will not power
Repaired power switch and tested.
-
Model: Intellivision
Symptom: Dead. Black screen.
Replaced 7407 and a bad 2N3906 transistor in the clock circuit. Tested.
-
Model: Odyssey 2
Symptom: Game crashes
Replaced bad 8048 CPU and tested. Replaced both joysticks and re-pinned the connector to the RF modulator. Tested.