Just fixed my 7800, having a lot of audio interference

[Spazmonkey]

As my title states, I just replaced the mje210 and 7805, and the baby works like a charm. Only problem is, the RF coming out is really weird. There's a lot of audio interference, and just a bit on the video, it's snowy exactly.... just unclear. I tried messing with the potentiometers on the board, the one long post one, and the two flat ones, but it didn't seem to do anything. So if anyone has any idea's, I'm all ears.

[GroovyBee]

Did the video and sound work OK prior to the fault that caused you to replace the components in the 9v to 5v supply path?

[+Mitch]

As my title states, I just replaced the mje210 and 7805, and the baby works like a charm. Only problem is, the RF coming out is really weird. There's a lot of audio interference, and just a bit on the video, it's snowy exactly.... just unclear. I tried messing with the potentiometers on the board, the one long post one, and the two flat ones, but it didn't seem to do anything. So if anyone has any idea's, I'm all ears.

 

It's sounds like your RF modulator is slightly off. You need a plastic RF alignment tool and you align it by adjusting the control inside the hole on the side of the modulator.

 

It's also possible that your RF connector on the 7800 is loose. If your RF cable that plugs into the 7800 doesn't connect solidly that could be the issue.

 

Mitch

[Spazmonkey]

As my title states, I just replaced the mje210 and 7805, and the baby works like a charm. Only problem is, the RF coming out is really weird. There's a lot of audio interference, and just a bit on the video, it's snowy exactly.... just unclear. I tried messing with the potentiometers on the board, the one long post one, and the two flat ones, but it didn't seem to do anything. So if anyone has any idea's, I'm all ears.

 

It's sounds like your RF modulator is slightly off. You need a plastic RF alignment tool and you align it by adjusting the control inside the hole on the side of the modulator.

 

It's also possible that your RF connector on the 7800 is loose. If your RF cable that plugs into the 7800 doesn't connect solidly that could be the issue.

 

Mitch

 

Cool, I will play around with that. It was sitting on my back burner for a few months, but I didn't touch it at all, so I'm surprised it got un-calibrated.

[Spazmonkey]

As my title states, I just replaced the mje210 and 7805, and the baby works like a charm. Only problem is, the RF coming out is really weird. There's a lot of audio interference, and just a bit on the video, it's snowy exactly.... just unclear. I tried messing with the potentiometers on the board, the one long post one, and the two flat ones, but it didn't seem to do anything. So if anyone has any idea's, I'm all ears.

 

It's sounds like your RF modulator is slightly off. You need a plastic RF alignment tool and you align it by adjusting the control inside the hole on the side of the modulator.

 

It's also possible that your RF connector on the 7800 is loose. If your RF cable that plugs into the 7800 doesn't connect solidly that could be the issue.

 

Mitch

 

 

I re-flowed the joints, and tried tweaking the pot, but it didn't aleviate the problem. In fact, I had to re-adjust more to undo what the adjusting did, if that makes sense. It looks like I'll just s-video mod it, and be done with it.

Cool, I will play around with that. It was sitting on my back burner for a few months, but I didn't touch it at all, so I'm surprised it got un-calibrated.

Edited September 20, 2009 by Spazmonkey