Plasma meter and vu pinned.

[MarconeMusic]

Hey.

Wondering. What would cause my plasma meter for the RF signal to be pinned full, which in turn makes the associated Vu to pin. No signal passing at time of this. 
The vu works normally and responds correctly when the plasma is removed.
The plasma and vu are on the same small ribbon cable for signal.

Plasma was working for the first hour and then now stays pinned to the top.

[MarconeMusic]

To add:
The plasma is pinned whether it has signal cable or not. 
Has power via the large ribbon cable.

[MarconeMusic]

Also, the pinned signal on the plasma is on the ppm side. On the "vu" side it's at -10

[MarconeMusic]

One last piece.
If it's in "vu" mode the signal shows -10 without the signal cable, and when I connect the signal cable, the plasma shoots up to the top and he vu pins as well.

[amillar]

Oh gosh - I remember this was a common fault but cannot remember what causes it (we're talking 30 years ago). It's the plasma meter giving dc out in it's input lines. Most plasma meter faults can be fixed by thumping the desk very hard above the meter! The problem is the silly forked connectors between the front panel and the side boards, and a good thump (on new desks) used to knock them into place. Of course, on a 30/40 year old desk it might make it worse...since it's only one meter it would be worth dismantling it and VERY CAREFULLY squeezing the connector forks together. Remembering to give it a good ten minutes (maybe half hour) between turning it off and working on it - the capacitors hold the high voltage charge for ages.
If I remember more about this I'll post!

I really hate the SSL plasmas...

[MarconeMusic]

Thank you! I will check that one meter out shortly...

I've found some other odd issues, Im gonna recap the whole system and then check it all out again.

I have tested every meter, One by one, on one ribbon and nothing else attached, they all work.

Once i put them all in and connect them all up, i get some that are glitchy... im guessing a voltage issue? or Connection on that pin thing.

Gonna recap and at the same time pinch the pins and see how that fixes it all.

[waltzingbear]

that seems to indicate that it is connectors that are giving you problems. Spend your time going thru and cleaning and re-tensioning the connectors not recapping. That will probably fix your problems if each module checks out well already.

Then, when the system is working correctly, you can evaluate and see if recapping is needed. Keeping the activities separate will cause you less grief in the long run.

Cheers
Alan

[radardoug]

Sometimes its the meter nuts holding the board on to the meter. The bolts inside the meter come loose. Remove the board, make sure the bolts are tight in the meter, refit the board.

[MarconeMusic]

Thanks for the replies!

What bolts holding the meter are you talking about? The screws holding the cards down ? I didnt notice any bolts, but i wasnt looking for any. . . 

[amillar]

Yes, those screws.

[jimlfixit]

For the record, those screws securing the two PCB's to the Plasma meter front assembly are M2 x 12 (or 10mm?) pozipan zinc plated screws. That's about all I can add to this as I'm not technical!

[MarconeMusic]

I tested them all out, most are good,  i had to "tighten" one of the meters connectors and got it back up and running properly. Im at 95% plasmas working right... I also have 20 Spares and 25 "Tubes" as spares to that...

I also recapped the meter distribution card and the power cards section for the plasmas... just incase....

The master meter is still pinned and i've fixed its connections, re capped it, checked it out as much as possible.. im at a loss...

VUs work fine without that particular plasma connected via signal... Its acting like it has a full tilt signal...weird.

Side note, my phase meter is acting weird and hanging to the right and bouncing around during playback.. not sure why that might be...