Berty
09-21-2004, 07:19 AM
Hi,
I have been trying to repair my US model sega cd. When I recived the system it was dead so i immediatly changed the fuse. The system then powered up, but for only a split second. Both the red and green lights came on and then went off.
I then cleaned VERY thoroughly the connection between the SCD and Genesis, both inside the connector and the contacts on the genesis. I then tried to power on again, but the same problem happened. I then dissasembled the whole unit and cleaned every connector possibe, but still the same things, the unit powers on for about half a second then turns off.
I have tried using different combinations of Genesis/SCD units and triple checked my power supplies.
My next step was to pull out the multimeters. I tested the input and output to the fuse; nothing. I then took the fuse out and it was fine. I then checked the continuity accross the fuse and it was fine.
The diode after the power input also proved fine, 13.8volts were running through it. I then moved onto the B963 power regulator, 13.8 V in and 13.8 V out; fine again. So this leads me to think that the problm lies between the voltage regulator and the fuse.
What i am thinking of doing is soldering a wire from the output leg of the voltage regulator to the input leg of the fuse (but removing the first keg of the fuse from the mobo to prevent a short). I will also put i diode in between the voltage regulator and the fuse.
I know that i will be bypassing something, but from what i have heard, 13.8 volts is the voltage that you are meant to be reading after the fuse as well. The way i figure it is that the worst i can do is blow the fuse.
Is there any other components before the fuse that i should be checking or am i missing something altogete? Also does anybody have any suggestions before i do this?
I have been trying to repair my US model sega cd. When I recived the system it was dead so i immediatly changed the fuse. The system then powered up, but for only a split second. Both the red and green lights came on and then went off.
I then cleaned VERY thoroughly the connection between the SCD and Genesis, both inside the connector and the contacts on the genesis. I then tried to power on again, but the same problem happened. I then dissasembled the whole unit and cleaned every connector possibe, but still the same things, the unit powers on for about half a second then turns off.
I have tried using different combinations of Genesis/SCD units and triple checked my power supplies.
My next step was to pull out the multimeters. I tested the input and output to the fuse; nothing. I then took the fuse out and it was fine. I then checked the continuity accross the fuse and it was fine.
The diode after the power input also proved fine, 13.8volts were running through it. I then moved onto the B963 power regulator, 13.8 V in and 13.8 V out; fine again. So this leads me to think that the problm lies between the voltage regulator and the fuse.
What i am thinking of doing is soldering a wire from the output leg of the voltage regulator to the input leg of the fuse (but removing the first keg of the fuse from the mobo to prevent a short). I will also put i diode in between the voltage regulator and the fuse.
I know that i will be bypassing something, but from what i have heard, 13.8 volts is the voltage that you are meant to be reading after the fuse as well. The way i figure it is that the worst i can do is blow the fuse.
Is there any other components before the fuse that i should be checking or am i missing something altogete? Also does anybody have any suggestions before i do this?