Problem with Scart Connection - Freeview

[Geff]

Since connecting a freeview box to my Bush DVRHS02 Combi DVD VCR recorder I have had problems with the VHS tapes. If I insert a tape the machines controls freeze and the tape appears to fast forward. Nothing will stop the machine other than switching off at the mains. I thought this was a faulty unit (the Bush) and managed to get a replacement but unfortunately the same thing happened.
Now here is the the strange bit if I disconnect the Freeview Scart from the Recorders 2nd Scart input (Blue) everything works fine. Replace it and I get the problem with a jammed machine and chewed up tapes. I recalled having a similar problem connecting a skybox with this machine and managed to find a solution. I fitted a two way Scart switch between the freeview box and the recorder and everything works fine. I don't even have to use the switch box, it just appears to reduce the input and allows the recorder to work OK.
I wouldn't have thought a Scart would affect a machines operation in this way and would appreciate if anyone could explain this weird phenomena.
Regards
Glynn (GF)

[Gavtech]

This IS a weird one. I've not come across it before.

The only possible route I can imagine for this problem is via PIN 12 of the scart... which presumably was not wired at all in the switch, which is why it stopped the problem.

Pin 12 along with Pin 10 forms an I2C bus which is a chip intercommunication standard that permits different chips to talk to each other and share commands. It is used for smart control functions on interlinked equipment.

I can only think that some innapropriate instruction is reaching one of the transport control chips [ or the main processor in the Bush ] and causing this problem.

If you could be bothered you could test for this by recessing pin 12 into the body of the plug [ press in the retaining lug with a watch screwdriver... Leave it in its channel , but far back enough not to make contact. ] to see if the problem disappears.

[JayCee]

Originally Posted by Gavtech

This IS a weird one. I've not come across it before.

I have...in my case the owner had a Packard Bell Freeview box and a Daewoo VCR-DVD Recorder and the same symptoms occured...when the Freeview box was plugged in to the AV2 input of the DVDR the VCR went crazy, f-forwarded to the end of the tape and would not eject...I never got the chance to investigate because the owner got rid of the Freeview box.

[Gavtech]

Originally Posted by JayCee

I.I never got the chance to investigate because the owner got rid of the Freeview box.

That's a pity.

I'm wracking my brains to imagine what kind of function might have been intended.
As it stands it looks like an incompatibility.