Fading Composite output
Posted: 19 Dec 2021 09:46
Hi
So the CFXII is purring along nicely however after all the work changing caps and getting the machine back up and running I now find that after around 5 minutes the composite output has faded out and the TV has lost signal.
As part of recapping the motherboard I recapped the video board and everything seemed fine at the time. I thought maybe the one of the regulators was an issue as one (the 5v) had pins soldered onto it and then to the motherboard. I just replaced all 3 and have a nice stable voltage with no change when the video fades out.
The issue seems to be related to the video board as if I unplug it and plug it back in (without powering Down the MTX) it starts working again for awhile. Due to this I don't think its heat related but was wondering if it could be the LM1889 as I did see a voltage drop on the output pin?
I don't own a oscilloscope unfortunately.
Has anybody experienced anything similar?
So the CFXII is purring along nicely however after all the work changing caps and getting the machine back up and running I now find that after around 5 minutes the composite output has faded out and the TV has lost signal.
As part of recapping the motherboard I recapped the video board and everything seemed fine at the time. I thought maybe the one of the regulators was an issue as one (the 5v) had pins soldered onto it and then to the motherboard. I just replaced all 3 and have a nice stable voltage with no change when the video fades out.
The issue seems to be related to the video board as if I unplug it and plug it back in (without powering Down the MTX) it starts working again for awhile. Due to this I don't think its heat related but was wondering if it could be the LM1889 as I did see a voltage drop on the output pin?
I don't own a oscilloscope unfortunately.
Has anybody experienced anything similar?