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ChromaTalk Archives: March 2003

Chroma Fan Manual & Pictures

David Clarke [21030085++]

We've all heard about Chromas with fans. I myself have never seen one.

The next best thing to seeing one (I guess) is to understand where/how the fan was intended to be installed.

The installation manual and pictures of the fan are now available at the site.

(As a side note, you'll see that the fan connects under the right-hand vents in the Chroma's top. Not all Chromas actually have the studs/bolts mounted under there - so I guess there's no easy way to add a fan to those units).

Expander For Sale

Chris Ryan [21030691]

With Syntech/Chroma Cult interface. It has power but does not boot - has worked very well in the recent past. Has latest eprom revs. Sold as is. Offers to Mark Smith: [e-mail address removed].

Chroma For Sale

Chris Ryan [21030691]

Controls not working, no audio. $500. Must be picked up in the San Francisco Bay Area. Contact Doug Terrebonne at [e-mail address removed].

Error 14

Csaba Zvekan [21030495]

Hi Chromanians,

I'm pretty new in this forum. I have a Chroma from a friend that wasn't working I accuired it for 400sFr. which is near 300USD. I discovered that the Battery was missing ... so I installed a Battery that was originaly for a SCI Drumtracks. So I got power the led's will be on totaly random. Then I brought the synth to repair. He fixed the connection cables between the CPU Board and the one next to it. Then it was working for 10 times out of scale of course. And now it constantly gives the Error 14 Messag. Anywhere I can download the technical Manual that tells me what this is. And do we have any Schematics to download ? Also he's saying that perhaps the OS. in the EPROM might have degraded from age. Anybody has a burner and can get this done for me???

David Gowin [21030611]

For the service manuals, check the Manuals page.

Jimmy Moyer [21030184]

"Error 14" is an indication that two of your voice circuit boards are failing the startup self-test routines. That you are getting this message is a pretty good indicator the firmware is running. If you're some experience, or someone else with experience, the Chroma service manual is very useful. I'd start by verifying all the power supply outputs - often a Chroma weak spot.

Csaba Zvekan [21030495]

Thanks Jimmy,

Sorry, this is a misunderstanding. I just checked with the technician that was working on the chroma. He's saying that about ten times the chroma was powering up and after that it wouldn't even finish the routine. So he's got it working for ten times and now it's not even booting up. I'll get the synth back and scope the Power Supply and power rails for proper voltages.I'll let you guys know. It says in some mod's the voltages should be a little higher than +5 -5 +12 -12. My question how much more ?

Also do we have some factory preset's to load ? A wave or something ?

Chris Ryan [21030691]

Also do we have some factory preset's to load ? A wave or something ?

There are hundreds of patches in various formats at the site: see Patch Downloads.

Weak Powersupply - Replacement in Europe?

Michael Zacherl [21030253]

Hello All,
I joined recently - thanks a lot for running this list!!

I own my second hand Chroma now for appr. 10 years and it was sitting in it's case for about the last three years - remaining unused (shame on me).

Besides the damaged finish of it's case (from the deteriorated foam of the Anvil case) it fails to power up correctly.

Some LEDs are randomly on (changes any time I power on) and there's no sign of life in the small LED-display. And of course no sound.

Reseating the soundboards didn't help.

Until now I didn't find where to measure the power supply's voltages, but at the vcc/vpp pins of one of the numerous logic chips I measured 4.87V. Reading suggestions, that this voltage is recommended to be rather 5.05V I'd guess that the power supply fails to work.

Anyway - it looks like that this baby needs some serious overhaul :-(

So it would be logical to replace the PS.

Q: Did anyone in Europe do a replacement like described in [Don Tillman's Nuclear Powered Chroma article] ?

Where can I get this switching PS?

Besides performing such a major operation what tests can I do, to get some more information to determine what fils in this unit? I'd like to see it running before taking it apart and invest a lot of time (and money).

Thanks a lot, Michael, Vienna.

PS: The new link for the map80 data sheet is http://www.power-one.com/resources/products/datasheet/map80.pdf

Sandro Traversi [21010217]

B4 any changes , take a deep cleaning to all the boards. Try also to disconnect flat cables , clean and reconnect. And chack again.

Don Tillman

Until now I didn't find where to measure the power supply's voltages, but at the vcc/vpp pins of one of the numerous logic chips I measured 4.87V. Reading suggestions, that this voltage is recommended to be rather 5.05V I'd guess that the power supply fails to work.

So it would be logical to replace the PS.

Not necessarily.

First off, you should only attempt a power supply replacement if you're really good at electronics. A single mistake could easily set your Chroma on fire.

Secondly, a slightly low output voltage isn't the typical failure mode of the original power supply. It would probably be best to go through the calibration procedure in the manual.

Q: Did anyone in Europe do a replacement like described in http://www.till.com/articles/ChromaPowerSupply/ ?

A nice feature of switching supplies like the PowerOne unit is that they work over a really wide range of input voltages, including all worldwide line voltage standards. So they adapt automatically.

Where can I get this switching PS?

The PowerOne web site lists distributors all over the world.

PS: The new link for the map80 data sheet is http://www.power-one.com/resources/products/datasheet/map80.pdf

Sigh.

As a web site writer, I've discovered that any time you make a URL reference to a company's product, that company will suddenly decide to redesign their website so the reference will no longer work. Feh.

David Clarke [21030085++]

I own my second hand Chroma now for appr. 10 years and it was sitting in it's case for about the last three years - remaining unused (shame on me).

Besides the damaged finish of it's case (from the deteriorated foam of the Anvil case) it fails to power up correctly. ...

I tend to agree with the other responders from the list, in that there are a few other (easier) things to check before looking to do a power supply swap.

If the keyboard has been stored for the past 3 years, it would be worth taking a quick look at the CPU board and make sure that the two AA batteries haven't leaked. If they have, then some cleanup/repair will be required.

It is also a good idea to make sure all the connectors are firmly connected - especially the flexible ribbon going between the CPU board and the IO board.

Here's hoping you have some good luck in bringing the keyboard back to life.

If you run into any problems and have questions, just let us know.

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