Fostex G-16S Bad Caps?

[clongo]

Thanks for the great detail miroslav! I'm going to attempt taking it apart because I've got nothing to lose at this point. I'll probably try re-seating the cards to see if that fixes the meter issue and then move on from there. Yes I have all the original manuals and the service manual.

I remember reading those old Cubase newsletters so I bet I read your article. In fact I think I just threw out my copies a couple of months ago. Went to the old Steinberg HQ a couple of times back in the day when it was a converted house in the San Fernando Valley. I too miss those old Cubase/Atari days. You're right, it was a very efficient setup and I really liked the old b/w Cubase, I could get around that thing really fast. Didn't even have a hard drive, just booted off the floppy.

I'll post back to this thread if I run into any issues with the deck. Thanks again.

[mdainsd]

What tapes are you using? If it's your old Ampex 456 or 499 from back then it's probably just sticky shed syndrome.

This is not accurate. 499 has no issues with SSS. I use vintage 499 exclusively and have never had an issue with it.

[clongo]

I also did some research and they said that although there may be reports of tapes made into the 1990s, the Ampex 456 most prone to SSS was manufactured pre-1984, that by then they had better technology to test the formulations. That sound true?

[clongo]

I pulled the card that corresponded to the pegged meter display and swapped it with another slot, and the pegged meter followed the card, so I know it's the card. Looks like there's 4 caps, but there doesn't appear to be any leaking or swelling, so I'm just guessing that's the problem.meter.jpgG-16 Card.jpg Could it be something else on the card?

Thanks

[witzendoz]

Pure guesswork, but I had problems on a Tascam MSR16S with bad caps on the noise reduction boards, I am also guessing that the noise reduction board is the board to the right of the photo with the sony chips on it. Are there any miniature caps on the underside of that board (between the main and small board). The next thing is does the problem occur when the noise reduction is off and on or only when it's on?

The other problem could be that because the machine was stored there could be corrosion on the solder joints, might be worth taking out the boards and cleaning them with a suitable cleaner, also clean all the connectors where the boards plug in.

alan.

[clongo]

Thanks Alan. Problem occurs whether NR is on or off. Nope, no caps underneath. I'll try cleaning the board and connectors to see if that helps. I was actually quite surprised how clean the inside was. One small dead spider, but hardly any dust. I'm not even seeing a lot of corrosion.

[witzendoz]

The way there is signal on one channel and a small signal on the adjacent channel could mean there is some tracking across the circuit, I again assume that one board is for 2 channels? or do they have a board each? This problem could be as simple as a dry solder joint or bad connector. Disconnect all the cables and clean the connections.

Alan.

[clongo]

Each channel has it's own board. Maybe some adjacent crosstalk because the meter pegs so high?

[miroslav]

The G-16 "S" version is notorious for having it's Dolby S chips go bad (unilike the "C" version).

Not sure if when the "S" chips go bad, do they affect the channel regardless if the NR is on or off....?...but I've seen lots of folks with the "S" veriosn have similar issues.

[jpmorris]

The G-16 "S" version is notorious for having it's Dolby S chips go bad (unilike the "C" version).

Not sure if when the "S" chips go bad, do they affect the channel regardless if the NR is on or off....?...but I've seen lots of folks with the "S" veriosn have similar issues.

On the MSR-24S, the channels work if the NR is bypassed (I saw one advertised with obviously dead NR, the guy wanted a fortune for it), but the card design isn't going to be the same.

Is the daughterboard soldered on or socketed? If socketed, what does the card do with the NR daughterboard unplugged?

Either way, if the mechanical issues are crap tape and the machine has just one dead card, you should still be able to get something for it, though not as much as if all the channels were working.

EDIT: Thinking strategically here, does the machine work if the bad card is physically removed? It should, but there's a chance the processor will halt if one of the cards is missing.
Assuming it works, your best bet in selling the machine might be to pull the dead one and swap cards so that track 15 is the missing one. Track 16 is often used for timecode, in which case using track 15 can give you crosstalk problems anyway. A machine with a bad track 15 would still be very useful for a lot of work, especially if synced to a DAW or something.