AMS DMX 15-80s

AMS DMX 15-80s for parts / repair.

offers welcome, thank you.

We could trade my defective TC2290 for your AMS.  ;D
Joke aside, that´s a switchmode-PSU. Replace all tantalums, diodes and Zeners on that board and I´m pretty sure it´ll work again. A complete recap will do no harm, either.

the PSU part of the docs i got for the AMS DMX is very hard to read, i cant replace that burnt resistor until i get some more info.

tata said:

the PSU part of the docs i got for the AMS DMX is very hard to read, i cant replace that burnt resistor until i get some more info.

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Looks like it has the same color code as the one connected to TP3 (Yellow-Orange-Gold-Gold, a 4.3 ohm 5%?)

Did you ask AMS-Neve? Somebody over here reported that they still service these, though it´s quite possible that this person reported it >10years ago...

not yet, but i saw StudioElectronics' repair price on this.

metalb00b00 said:

Looks like it has the same color code as the one connected to TP3 (Yellow-Orange-Gold-Gold, a 4.3 ohm 5%?)

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possible, but id like to be sure before doing anything

tata said:

possible, but id like to be sure before doing anything

Click to expand...

ok, my bad.

from other low quality photos of the unit, it's difficult to distinguish between orange and red, therefore that resistor color bands are either yellow, red, black, gold (42R 5%) OR yellow, orange, black, gold (43R 5%)

with a 1 ohm difference between the two, I'd pick one, and be done with it.

thank you metalb00b00,

so far that seems right-ish, it should be R2 / 47R, 1%
will replace asap and report how the unit works then.

tata said:

thank you metalb00b00,

so far that seems right-ish, it should be R2 / 47R, 1%
will replace asap and report how the unit works then.

Click to expand...

jensenmann is correct you should replace all the tantalums.
a good choice would be a low ESR electrolytic capacitor like Nichicon UHE (which I see in a lot of switching power supplies lately)

thanks gents,

this is what ive got now:





but this doesnt mean its all OK. Cooler spins quietly, lights are on.. thats all i know so far.

I suspect that it´s working now because of the higher power rating of the new metalfilm resistor compared to the old carbon type. Somewhere in there is a close to dead tantalum across the supply rails which eats a lot of current hence overheated the old resistor. If you don´t recap that thing it will die again. Just an educated guess....

you are totally right, there are a few shorted tantalums on the cards, and at least one 5532 is dead.
what caps i should use to replace the tants, please? whats the best low ESR type for this application?
Nichicon, Panasonic i guess, but what model / type?

thank you

Panasonic FR, FC, FM are fine as are many more other brands. Make sure you´re using 105deg rated caps since they last longer.

I love that this "For Sale" post has turned into a repair thread   Please also replace the electrolytic caps in the power supply while you are in there.

thanks gents,

sure, i ususally use Nichicon PWM, thats rated 105C.
i will replace the PSU electros too as soon as the shops will open.

the blue PSU caps seem to have 3 legs, im not familiar with that. only 2 pins seem to be connected electronically tho.

offers are still welcome, but i enjoy cleaning and hopefully repairing this. the best way to learn, imo.

Sold, thank you.

Looking for DAC card for in beast like that

David Kulka is your man

http://www.studioelectronics.biz/sunshop/index.php?l=product_list&c=56

THANK YOU SO MUCH for posting this - I had the EXACT same thing happen to MY DMX. And in the year since I've been half heartedly digging around and trying to figure out what the value of that resistor was! For the record - in case anyone else has this happen  ... both the adjacent tantalum and diode went short circuit by the way - which was likely the cause. I guess I'll replace the tant with something more tolerant of voltage spikes.