Tascam DM4800 Hardware Defect

[Victor G]

Hi Everyone!
This is a doozy... I've exhausted more than Tascam could support and we are certain it's a hardware defect, likely the logic board of the console. Here is the setup, then the problem:

1. Interfacing the DM4800, IF FW card, and Logic X in a 2008 Mac Pro, 10.9.5
2. Tracks armed
3. ** Whether tape is recording or idle, at a completely random time (could be 10 mins or 10 hrs), there will be short blast of noise, then quiet, then all of a sudden all signals are delayed by approx a full second behind real time. The only way to fix is by rebooting either the console or the DAW or of course both.
4. Ruled out: swapping the computer, swapping the DAW - (Pro Tools will simply crash when this event occurs, where as Logic will remain open, with the delayed signals passing through) swapping the IF/FW card for a new one, cables, external vs internal WC, Logic 9 vs Logic X, the list goes on...

It so happens that the person I borrowed the new IF/FW card to test with had some identical issues and sent it for repair just inside of warranty. Months later, was determined to be the Logic board. He also mentioned that Tascam was aware of this defect when shipping certain serials.

We are a global education facility headquartered just outside of Vancouver, BC. We can't send it for repair even if it was still under warranty because our facility operates 5 days/week and there are no other options for replacements or rentals (short of getting an entirely different system...we use 90% of the entire I/O and internal routing). It seems as though my best option is to replace the logic board of the console myself. I came to this conclusion as we have a team of IT engineers, programmers, and studio engineers and can easily swap the part ourselves. How can we find this part to purchase?

Thank you all in advance!

 

[ampsarus]

Victor,
If I was in your shoes, I would start looking for a used 4800 on eBay.
I'm sorry if that comes off as a less than thoughtful answer, but that is what I would do. What methods were used to insure the SMPS isn't the culprit?

The way I see it, another 4800 gives you a full box of parts down the road, not just one PCB. I think it's a good value to keep your DM in service vs. the alternatives.

Best,

 

[Victor G]

Thanks so much for the quick reply!
In the PS regard, nothing other than full cycles, pull from the wall, card re-seats, etc...I can't see how the PS could have anything to do with the symptoms we're having.. Any extra insight into this thought?

I appreciate the idea and definitely true...Although buying a used 4800 runs the risk of this happening again, and allows for limited (or no) time on the 1-year warranty that comes with these when purchased new. Also, if the same problem occurs (which we are all almost certain it's the logic board), then I will essentially be in the exact same boat-not able to ship the console out, regardless of warranty status. Of course, another option is a new 4800...but I just really don't like that path...knowing that this happened to us and another studio in the same town... and knowing that if it happens outside of 1 year, we are extra screwed..

Thanks again for your help!

 

[ampsarus]

Victor,
I agree getting another 4800 on a prayer is a gamble. It follows a philosophy that not all share. Looking at other options and the time/funds required to fix a sick 4800 (new PCB, or entire new console) I believe your gamble will pay dividends now and down the road IF you find a good used board from an honest seller.

There was a thread several months back about a faulty 4800 SMPS, and that it is a rather generic ATXish supply with proprietary connections. IIRC the symptoms that user was having were similar, maybe not.
I searched back 12-13 pages on the 3200/4800 forum, back to when I got my own 3200, but could not find the thread I am thinking of.

Good fortune would have you find a used and perfectly usable 4800 at a good price, thus making your existing 4800 a happy 'box of parts' down the road. ;-)

Best,

 

[Victor G]

Thanks Fiber!
This is the IF/FW MKii card. As mentioned in the original post, we also borrowed a brand new IFFW MKii card to rule out as well.

 

[Victor G]

Haven't tried that...long shot but when I can open it up I'll take a look at that, thank you.

 

[Victor G]

Other than resetting the entire console and not reloading from a saved project, no we haven't... Any extra insight into that would be greatly appreciated..

 

[Gerk]

This might be a bit of a longshot, but have you tried running the console with an external wordclock? It might be worth giving it a try if you have one handy or one you can borrow to test it out with. That would at least rule out the whole word clock/sync part of the equation.

 

[GaryJackson]

Hey Victor,

I have had a similar problem but my issue was a tad different. I dont get the blast of noise but from time to time my DM4800 and the recording will be a second behind on Logic X. Looks good while recording but then when I play back it was about a second behind. A reboot solved that issue but Im lucky as it was only once or twice during an album or EP, so a very intermittent issue. Im not sure that its the same issue that you have and its probably not, but what I found helped my situation was to change some of the logic CPU settings regarding CPU usage. I changed my 12 core settings in logic to only use half the cores (8) and that seemed to solve my random recording issue. (At least it has not done it since and that was months ago)

Its a long shot but always worth a try as one problem might not be related to the other but to be honest they probably are and I wish I had a better suggestion.

I would also try rolling back the drivers and running alternative drivers for a week, that way you could rule out driver issues. I did hear at one time that people were getting alot of random noise on Mountain Lion and random pops, clicks and noise like distortion.

 

[RedBus]

I suspect a bug in the driver. Have you tried all of the V1.30f(x) versions?

See the sticky driver thread.

 

[waterstrum]

I've been having the occasional delayed track recording as Gary described.
Very rare, but very disconcerting.
A reboot fixes it.
I'm running Logic and DP on a Mac Pro.
I just downloaded what I think is the latest mac driver...
IF-FW/DMmkII V1.30f10
Is this the latest/best?
I'll give it a go and let you know.

 

[Gerk]

Yep that's the latest one.