VRDS 20 problem -isolation

[Miniwatt]

Hi all,

I've got a Teac VRDS 20 that I use as a transport. A few years ago I disconnected the analog boards as I didn't use them, more juice for the digital part and no interference etc.

Now I reconnected it all, and suddenly I have a weird problem.
There are two relais on the balanced board, and they click like crazy. A few clicks during power-up, when starting a cd, when paused, when skipping to the next track. And no sound whatsoever, just a few thumps. I checked whatever I could (I'm not a digital techie..) but there's nothing broken etc.
I also can't remember hearing those clicks when I first got the player, they're pretty loud.

Now the funny thing is that this does not occur when I use a mains isolation transformer...
Maybe it's too late, and I should sleep on it, but I'm completely lost here: what's the difference???😕
Does anyone have an idea?

Thanks for thinking with me!

 

[jitter]

Sounds like bad grounding (oxidation) to me, that can do really weird things. Thoroughly clean every connector on the board (and its counterpart on the cable) and try again.

 

[Miniwatt]

Sounds like bad grounding (oxidation) to me, that can do really weird things. Thoroughly clean every connector on the board (and its counterpart on the cable) and try again.

I will do that 😉

But once more: there's no problem when I use an isolation xformer (een scheidingstrafo). That has something to do with grounding too of course I just don't know enough about these things

The connectors haven't been used in years, so your point of oxidation makes perfect sense..

 

[georgehifi]

When you disconnected the analog board did you remove all 3 connectors shown?

Cheers George

 

[Miniwatt]

Thanks!

Mine's a bit different:

I disconnected the two connectors coming 'from the other side', circled in yellow.

BTW I didn't cover the chips with copper nor did I apply that white goo

 

[jitter]

But once more: there's no problem when I use an isolation xformer (een scheidingstrafo). That has something to do with grounding too of course I just don't know enough about these things

I don't know the reason for that either because the power transformer inside the Teac already isolates the player from the mains. It's an inherent trait of a transformer with separate primary and secondary windings (I'm assuming the VRDS-20 has such a transformer).

BTW, in your picture I see a black wire with a cable lug just hanging there. Shouldn't that be attached to the frame somewhere?

 

[georgehifi]

BTW, in your picture I see a black wire with a cable lug just hanging there. Shouldn't that be attached to the frame somewhere?

That's the earth for the harness shield, possible that could be the culprit.

Cheers George

 

[Miniwatt]

Sorry guys, I took everything apart to find the fault, and didn't screw everything back just to take a picture😀 The boards are loose too. Of course those earth lugs are connected when the player's put back together.

I'll try some connector cleaning tonight😎

 

[Miniwatt]

The connector cleaning didn't do much, so I just let it play for a while to see if a 'warm up' would help. And it stopped the clicking! But still no sound
As I had run out of options for the analog pcb I went back to the servo board. Although it's a major PITA to get it out
Previously I had altered the S/PDIF out, so I checked if I didn't miss anything when returning it to it's original state. Everything was fine, maybe some small particles on the pcb. I brushed it off and hey presto: it worked again!!
I've spent countless hours on the darn thing, so imagine my happy dance😀

End of this story, thanks for the help everyone!