Author Topic: CF82E10 Dynamics card issue SOLVED (Read 6841 times)

christiancarvin · « **on:** February 12, 2014, 04:02:07 PM »

When I turn on the dynamics with -20dB on threshold the level increases.
If I turn the threshold up the sound is distorted but ain't compressed.

I tried alignment and it leads to this:

With 10 dB on insert send I do have a decrease of +4dB when I press CH IN (with Threshold set to -20 ratio to infinity and release ACW)
When I pushback attack button (in slow position) the level doesn't increase of 1.5.
An other thing when I put the input at -20dB (0.0775V) and I press Ch IN (with Threshold set to -20 ratio to infinity and release ACW) the voltage jump to 0.167 (decreasing gain pot leads to 0.147 only)
Does it help to find a solution?

Thanks!!!

christiancarvin · « **Reply #1 on:** February 13, 2014, 11:44:07 AM »

It seems like this is an hard one!

sintech · « **Reply #2 on:** February 13, 2014, 01:33:49 PM »

Did you reseat the card, and clean the Dynamics 'In' button? These are the first checks for distorting Dynamics.

christiancarvin · « **Reply #3 on:** February 13, 2014, 02:13:53 PM »

I'll do that and make a report Sintech, thanks!

christiancarvin · « **Reply #4 on:** February 14, 2014, 01:20:12 PM »

Card reseated, Dynamic button in cleaned...nothing change, the problem still remain...(The card has been exchanged with a good one and the trouble follow the card)
Any idea for the next step?

sintech · « **Reply #5 on:** February 14, 2014, 01:46:54 PM »

Did you switch the IC's? that's the next thing to do.

christiancarvin · « **Reply #6 on:** February 14, 2014, 03:31:22 PM »

Yes I did that, the trouble follow the IC.

sintech · « **Reply #7 on:** February 14, 2014, 03:37:08 PM »

Change one at a time, till you find the bad IC.

Do you have an extender with a power rail switch? It's the perfect tool for fast changes.

christiancarvin · « **Reply #8 on:** February 14, 2014, 03:50:27 PM »

Sorry I've just understand the meaning of IC (poor french man I am!)
No, I didn't exchange them...
Thanks for your patience Sintech!

I have the extension I'll do that (and hope That does not comes from the Ad536 component caus' I don't have any in spare)

christiancarvin · « **Reply #9 on:** February 14, 2014, 06:22:34 PM »

Do you think I can exchange CA324E with MC3403N? They're both present on CF82E10 Dynamics card at the same place but I can see some differences on the card....Thanks!

christiancarvin · « **Reply #10 on:** February 14, 2014, 10:46:13 PM »

All the Ic's have been changed. the problem still remain
I didn't change dbx 2151 because I don't have any in spare...
A difficult one!

walrus · « **Reply #11 on:** February 15, 2014, 07:01:35 PM »

How old is the Dynamics card? Has it been re-capped?

The reason I ask, is that when I was re-capping our desk, some of the old, orange coloured electrolytic capacitors had leaked onto the card. This was causing the copper track to oxidize under the etch resist, and when I soldered in the new caps, the through hole plating was so oxidized the solder wouldn't flow through, leading to no connection between the two side. Also the through hole via's (taking tracks from top to bottom) were not connecting properly and had to be cleaned out, then re-soldered.

I had quite a few boards that had problems like yours, but most of them were cured by re-soldering joints and cleaning the boards up to get rid of the leaked capacitor electrolyte residue.
I think out of 56 channels, I only had 3 or 4 that were IC faults.

christiancarvin · « **Reply #12 on:** February 16, 2014, 04:02:54 PM »

Thanks,
The card has been recently recaped.
Here is a picture

Is there anything to do with TP1, TP2, TP3 to localise the problem?

walrus · « **Reply #13 on:** February 16, 2014, 06:40:42 PM »

As I posted in your other post, the line-up procedure is in the Tech Docs section. That will tell you what to do with the test points.

Your board is a later version than the ones in our desk, and look clean with no corrosion.

What I can't work out though is why C5 and C6 are missing from your board. I'm not at work at the moment so I don't have easy access to schematics.

christiancarvin · « **Reply #14 on:** February 16, 2014, 08:56:57 PM »

Hey! I didn't notice that, brillant!!
I'm going to check that tomorrow.

I'm sorry, I'm very novice, I can't see the relation between the 611 procedure and the Test point I was talking about.
I understand the meaning of the 611 procedure but I can't see any direct link with TP....

Thanks for your help!!

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