jensenmann

AMS RMX16 question
« on: December 15, 2006, 11:10:19 AM »
I´ve been offered a RMX16 Reverb for a pretty good price but it seems to have some problems with the display. A few LEDs don´t work for whatever reason. Is anybody here who teched one of them and could tell me if it´s a big effort to repair this? Are the parts (7segment/driver ICs) still available? Are the parts accessable or are they potted?
Rumour says that the RMX16 is hard to repair so I´m asking in advance before I throw out bucks for having a nonrepairable piece of crap which gives me more grey hair than I already have.

thanks :thumb:
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort


echorec

AMS RMX16 question
« Reply #1 on: December 15, 2006, 05:45:11 PM »
Can´t help you but I have a RMX16 with the same problem. I use it anyway and it sounds fantastic but I would also like to know if it´s fixable.

Michael Tibes

AMS RMX16 question
« Reply #2 on: December 15, 2006, 07:55:29 PM »
It's been perhaps 10 or 15 years since I worked on these, but I remember that they are a very delicate (hmmm, maybe just bad) construction. Loads of flatwires which run over sharp edges, getting cut in and creating all kids of intermediate connections, a fan pulling dust, a battery that gets overcharged is what I recall immediately. Fixing that made them pretty reliable. I have no idea for the LEDs, buffers should most likely not be a problem and all parts are accessible - if I remember right. I don't remember anything potted.

Michael

SteveAudio

AMS problems
« Reply #3 on: December 15, 2006, 08:17:17 PM »
I spend a lot of time working withe these folks: http://studioelectronics.biz here in the Los Angeles area. They have searched the world for documentation, spare parts, and info on RMX & DMX units, and have become pretty expert in their repair.

The problems you are describing can very often be fixed by replacing the ribbon cables. That's part of Studio Electronics' basic DMX/RMX restoration process.

They've repaired over 100 units in the last 1.5 years, so that's a pretty good track record.

For more info, email [email protected].
Stephen Anderson

tomelectro

AMS RMX16 question
« Reply #4 on: December 15, 2006, 09:29:36 PM »
I've got a schematic of the front panel.  It looks like the 7-segment displays are multiplexed with an RCA CA3082 transistor array handling the data lines, and 75492 MOS to LED Driver ICs handling the chip selection.  Chip selection is decoded by 74LS273 chips.  There are a couple of 7406 ICs sprinkled in as well. 7-segment displays are TIL313's and TIL327's. The alhpa-numeric displays are TL1414 4-character "Smart" displays. I googled the 7 segment displays and got back mostly links to the giant surplus and obsolete chip vendor sites, so they may be tricky to source.

There are no potted parts inside.

As mentioned, Studio Electronics has a good reputation for AMS repairs, but I would discuss it with them before buying the unit, to avoid any repair cost sticker shock.

AMS RMX16 question
« Reply #5 on: December 16, 2006, 02:48:17 AM »
David Kulka, is a vary nice fellow.  He fixed my AMS delay, but it was a nasty audio problem.  Give a call he may tell you the LED replacement or send you some.  He can also be found on ebay advertising his repair services.


I replaced some segment LEDs in a Klark teknik and it was a PITA.  Sourcing was also fun, but it looks like you have more going on than a bum LED segment.

jensenmann

AMS RMX16 question
« Reply #6 on: December 16, 2006, 05:53:39 AM »
Thanks a lot for you help, gentlemen. This information really helps me.

YOU GUYS ROCK!!!

 :grin:  :guinness:
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

Walrus

AMS RMX16 question
« Reply #7 on: December 16, 2006, 12:13:22 PM »
There is also the chap in the UK who was *the* service engineer for AMS. His name is Howard Jones. Unfortunately I don't have his details here at home, but I will post them on Monday when I get to work. He now has his own company still repairing AMS's.
Kevin.

AMS RMX16 question
« Reply #8 on: December 16, 2006, 01:05:56 PM »
I heard Howard Jones cut himself off from this line of work.  or maaybe he's just retired

David Kulka

AMS RMX16 question
« Reply #9 on: December 16, 2006, 01:49:18 PM »
Hi folks and thanks for the kind words.  This is my first post on this forum.  Actually there were other topics that I wanted to comment on, but I had trouble registering.  Anyway, hello.

Jensenmann, as Steve Anderson mentioned, check the ribbon cables first, specifically the two short ones that go from the microprocessor board (the board on the right, near the transformer) to the front panel.  You might try flexing and moving these slightly while the unit is running.  If anything changes on the display while doing this, you have a bad cable.  

Also, you could probably "borrow" the long cable that goes to the remote connector, and use it to replace the front panel ribbons, one at a time, to see if the problem clears.  If you do this, make notes or take pictures before you unplug anything, and be very careful not to plug anything in backwards.

It's possible to have a problem in the IC's on the front panel, but this is rare.  We have never seen a 7-segment display fail on any AMS; it's extremely unlikely that this is the problem.  The microprocessor board would be more of a suspect than anything on the front panel.  But again, the ribbons are the first thing to check.  If they are really dusty and crusty looking, that tells you something.  Even if they look ok, it's not a bad idea to just replace them both with new cables, and see what happens.


Barish

AMS RMX16 question
« Reply #10 on: December 16, 2006, 01:50:57 PM »
Great to see you here, David, that was long due  :thumb:

Welcome.

Mach (aka Barish)

Walrus

AMS RMX16 question
« Reply #11 on: December 16, 2006, 08:06:52 PM »
Quote from: "guavatone"
I heard Howard Jones cut himself off from this line of work.  or maaybe he's just retired

The last time I spoke to him he was still in business. That was over a year ago, but he was still working on them then.
Kevin.

jensenmann

AMS RMX16 question
« Reply #12 on: December 17, 2006, 05:34:15 AM »
thanks, David and welcome aboard
 :grin:  :thumb:
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

AMS RMX16 question
« Reply #13 on: December 17, 2006, 02:26:49 PM »
Thanks for dropping by David, and sharing some quality troubleshooting advice.  (BTW I am the guy who's AMS you serviced through Paul Fox, and later sold you the Broadcast DMX)

Walrus

AMS RMX16 question
« Reply #14 on: December 18, 2006, 11:37:22 AM »
Update...

Just tried getting hold of Howard Jones. His website no longer exists, and the phone number I had for him is saying "This number does not take incoming calls".
So it looks like you are right Charlie, which is a great shame and a great loss.
Kevin.

Rob Flinn

AMS RMX16 question
« Reply #15 on: May 25, 2007, 09:43:21 AM »
Anyone know of a good place to get an RMX16 serviced in europe.   Preferably France, although elsewhere is also good   ????/
regards Rob

gyraf

AMS RMX16 question
« Reply #16 on: May 25, 2007, 09:49:16 AM »
I think we had AMS/UK fix ours some years ago (iirc they repaired these at a flat rate..?)

Jakob E.
..note to self: don't let Harman run your company..

Rob Flinn

AMS RMX16 question
« Reply #17 on: May 25, 2007, 10:07:56 AM »
Thanks Jakob
regards Rob

Rob Flinn

AMS RMX16 question
« Reply #18 on: May 25, 2007, 01:09:32 PM »
I just received an email from the AMS Neve service dept.

For reference they do not service the 15-80S, SDMX, RMX-16 anymore.
regards Rob

gyraf

AMS RMX16 question
« Reply #19 on: May 26, 2007, 02:36:10 AM »
:shock: ....Ouch....!
..note to self: don't let Harman run your company..


 

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