DFP-D3000 won’t decode SDDS

[Kieran Hall]

Hi everyone

Our Sony DFP-D3000 has decided it doesn’t fancy decoding SDDS any more. When film is running, the S and P side status LEDs behind the front panel flash pretty much randomly, and weirder still they continue to flash when film has stopped running. Naturally the processor “sees” as a failed track and stays in fallback mode, but on the odd occasion it manages to go into SDDS mode the OVER lights for every channel light up like a Christmas tree and it puts out heavily clipped 0 dBFS noise on every channel (was playing some SDDS trailers – at 7.0 – for crew at the time, our ears are still bleeding!).

We run changeover and both projectors were affected, so we assumed it was the processor and luckily enough managed to get a replacement from eBay which works fine. I’m guessing this a long shot and that the old one is basically junk now (or at least one of the boards – DEC-102 presumably?) but thought I’d ask if anyone has come across this on the off chance it’s repairable, as it’d be nice to have a spare.

Thanks!
Kieran

[Mark Gulbrandsen]

Had the same issues with both the 2000 and 3000 units and it was always the LED's had faded beyond use. When all the 3000's that I serviced quit working or penthouse components wore out we replaced them with Dolby Digital because at that point in time, and for a little over a year, Sony could not supply any 3000 parts at all.

[Kieran Hall]

Hi Mark, we’ve replaced the decoder now and everything is working again, so I guess the penthouse readers should be fine? A little while ago we hooked up a serial cable to both readers and ran their “shading” self-calibration and there were no complaints of low LED levels.

Would just ideally like to get the old decoder back up and running if such a thing is feasible, because who knows how much life the replacement has left either.

[Mark Gulbrandsen]

Hi Mark, we’ve replaced the decoder now and everything is working again, so I guess the penthouse readers should be fine? A little while ago we hooked up a serial cable to both readers and ran their “shading” self-calibration and there were no complaints of low LED levels.

Would just ideally like to get the old decoder back up and running if such a thing is feasible, because who knows how much life the replacement has left either.

Glad to hear the LED's checked out ok, the 3000 LED's were a bit better than the 20000 arrays that were being used in the beginning.. I doubt you'll get the decoder board repaired any longer as Sony would have to do it. But you could contact Sony Professional and ask them. The best bet, and usually the least expensive route is to always be on the lookout for another unit that can either be subbed in place of yours or used as spares..

[Stefan Scholz]

Probably your DEC 34 board went bust.
This is a typical fault you describe, had this on mine and a couple of others, also. Thinking, it was the first lead free solder product, it must fail due to the environmentally friendly soldering used.
This builds little tin whiskers, that can carry a milli Amp. Signal currents are micro Amp. Spares will have same age, same problem.
Zou can ask Sony professional, if they still repair or carry spares. I doubt. The whole product line was discontinued a long time ago. And if, be prepared to pay top dollars.

These units are mainly interesting for repertoire and museum cinemas, and they require working decoding. It is becoming a problem, like any proprietory technology.

[Mark Gulbrandsen]

Tin whiskers can some times be dealt wit by using a fine metal whisker brush around pins of integrated circuits. Otherwise s9older reflow equipment would need to be used. The latter is way more difficult.

[Randy Stankey]

Don't forget Tin Pest.

Most lead-free solder formulations are prone to it. At temperatures below approximately 55 deg. F. tin begins to change from its β-form (allotrope) to its α-form where it loses conductivity and, eventually disintegrates and turns to powder.

The process is autocatalytic. Once it begins, it gradually speeds up until all the tin has changed form.

Reheating the tin until it reaches its liquid phase and cooling can restore it to β-form but, if you are reheating a complete circuit board, you have to be careful not to damage the board or the components.

Many components are heat sensitive and their maximum temperature is only a few degrees above the melting temperature of solder. Get them too hot or hold them at a high temperature for too long and you're done for!

Many components are moisture sensitive, too. They absorb water vapor from the air. If you heat them above the boiling point of water, the steam generated inside can cause them to pop like popcorn!

Most tin-silver solder melts at 221 deg. C. You don't need a reflow oven but you need a temperature controlled oven capable of accurately sustaining temperatures that high.

Before you start, remove all extra components that can be removed, especially anything that might be heat sensitive.
Put your board into a room temperature oven and ramp it up to 125 C then bake it for at least 24 hrs.
Next, ramp the board up to about 180 C and hold it there for a few minutes to be sure that all the components are at temperature.
Bring the board up to 225 C, over a period of two minutes, let it stay there for a minute then let it come back down to 180 C.
Keep it there for a couple minutes then turn the oven off and let it cool naturally, back to room temperature.

This is the process that workers in electronics manufacturing plants use to rework circuit boards.
They use either a tabletop, temperature controlled oven, about the size of a microwave oven or they use an infrared heating pad, about the size of an unabridged dictionary.

It's not exactly a straightforward process but it is done in shops every day and, if you are industrious enough and work carefully, I'm sure that you can do it in your home workshop.

If the board is non-functional, you haven't got anything to lose by trying. Right?

[Marco Giustini]

Randy's method could work - even though ideally you want to use a dedicated IR oven and not a standard household one. Besides the temperature accuracy, I am not sure I would bake an electronic board in the same place where I bake my vegetables. Indeed it's a lead-free board but it will still contain chemicals which I would be happy to keep away from my eating plate

(same applies to washing PCB's in dishwashers to be honest)

[Randy Stankey]

I wouldn’t do it in a kitchen oven because it’s temperature control isn’t accurate enough or precise enough to keep the right temperatures for the right amount of time to do the job. Furthermore, the process takes a whole day. Your whole kitchen would be out of commission the entire time.

Your wife or significant-other would be pretty pissed off!

Yes, contamination is an issue, too... Both ways. Not only could the board contaminate your oven but the oven could contaminate the board.

You should get a temperature controlled heating device that can be used just for the purpose.

[Marco Giustini]

I'm glad that we agree on that, Randy! Thanks!

[Tony Bandiera Jr]

I wouldn’t do it in a kitchen oven because it’s temperature control isn’t accurate enough or precise enough to keep the right temperatures for the right amount of time to do the job. Furthermore, the process takes a whole day. Your whole kitchen would be out of commission the entire time.

Your wife or significant-other would be pretty pissed off!

Funny you should mention that...

Back in my days before I was a cinema tech, I worked at Knott's Berry Farm as a sound and show tech. One October I had to set up three amplifiers and speakers on the roof of the Calico Saloon for the sound efx used during the Haunt. I used two Yamaha amps and one QSC 1400. I set the amps on boards to keep them off of the roof surface, and powered them up. I called audio central to send me the park background music to test and set levels. After all that, I went home at the end of my shift. (I should mention that Knott's policy is everything stays powered up 24/7 in the audio systems.)

I woke up at 2 am to the sounds of heavy rainfall. I realized that I had not covered those amps up and cringed at what I would find when I got to work that evening. First thing I did after clocking in was go check on the carnage. When I got to the roof it was still wet with standing puddles. I slowly approached each amp..the two Yamahas were dead. When I got to the QSC, it was still powered up with the normal green light. I called for audio feed, and much to my surprise (back then I didn't realize just how well made QSC is) I got sound, and clean sound. I took both of the dead Yamahas back to the shop bench. I opened them up, saw no burned or obviously damaged components, then replaced the fuses, which promptly blew. So I set up a lamp on one on the bench to dry overnight, and took the other home to dry it out...in mom's oven.

Needless to say I was awakened early that next morning by a very pissed off mom who wasn't thrilled to see that huge thing merrily toasting at 175 degrees.

I survived, barely. But neither Yamaha was repairable and both ended up in the dumpster.