TC Electronic Studio Konnekt 48 revival

[barbas]

Re: TC Electronic Studio Konnekt 48 revival

I had some issues with my Konnekt Live, after I plugged it in with the FW cable reversed. In my case the FW connection was good but the DAW indicator in the control panel was grayed out randomly. I narrowed down the issue to the FW chip. What I did was to "cook: its pins with a bit of solder, hot air station and some flux. I have had issues before with other machines where a reversed voltage caused a weak solder point to break but not the device itself. I guess I was lucky! Worked wonders! Thanks to Khron and everybody else!

[Khron]

Re: TC Electronic Studio Konnekt 48 revival

Well, if the Dice is getting hot, and dragging down the 3.3v rail, i'm afraid the diagnosis is unfortunately pretty clear

Hello everyone,
this is my second attempt to repair Konnekt 48. For several years now, the sound card has been out of order because I didn't have time to dedicate to the repair. And now at the time of the corona-virus there was a little more free time so I decided to try to fix it again.

Since there is obviously a problem on my Konnekt 48 with the 3.3V rail, I tried using a power supply to insert that voltage after removing the L65 and L64, in between which the TR5 is located. The board pulled the maximum limited current from the power supply so that apparently something was shorted on that rail.
I tested all the capacitors in the first section before the 1.8V rail and everything is fine. The only thing that heats up on the whole board when 3.3V is on, is the Dice II chip which heats up in a very short time to a very high temperature. In addition, all capacitors near the chip are short-circuited when measured using a continuity test directly on the board.
Is there any other way to test Dice II before I declare him dead?

Sounds like you got off easy then Glad to hear the fix worked. Although don't be 100% shocked in case it "wears out" in time (thermal cycling and whatnot), if it's an internal bond-wire issue or something.

I had some issues with my Konnekt Live, after I plugged it in with the FW cable reversed. In my case the FW connection was good but the DAW indicator in the control panel was grayed out randomly. I narrowed down the issue to the FW chip. What I did was to "cook: its pins with a bit of solder, hot air station and some flux. I have had issues before with other machines where a reversed voltage caused a weak solder point to break but not the device itself. I guess I was lucky! Worked wonders! Thanks to Khron and everybody else!

[barbas]

Re: TC Electronic Studio Konnekt 48 revival

I am leaving here the schematics in case somebody needs them. Link is down for some weeks already.
Mr Khron was right. The easy fix did not last.

https://www.dropbox.com/s/k3c3kvwn9m...inter.pdf?dl=0

[solozabal]

Re: TC Electronic Studio Konnekt 48 revival

Khron, I saw your article about the process of changing the Dice II chip on the TC 48 sound card on your blog, well done. It doesn't look very simple to me, but anyway I would try to do that, so I have to somehow find a replacement Dice II first. I looked on ebay for some of the sound cards that use the Dice II chip (Konnekt 24D, Konnekt 6 and Alesis iO / 26), but I'm not sure if they use the same chip that I could use for Konnekt 48?

[Khron]

Re: TC Electronic Studio Konnekt 48 revival

Well, i was relatively fortunate that the ball pitch wasn't too-too fine, still workable by hand.

And as you can see on my other teardowns, the Alesis io|26 as well as the Konnekt 8 / 24D all use the same Dice II chip.

I took mine from a "donor" Konnekt 8 that i got years ago, that had a screwed up ATMega microcontroller (that handles the encoders / buttons / LEDs for the front panel). The 24D's virtually the same unit, with a second codec, a couple more opamps, the SRAM spots populated and different firmware. Can't say for sure about the Konnekt 6, but that's a "maybe"; see if you can find any internal photos online.

[jons]

Re: TC Electronic Studio Konnekt 48 revival

Thanks for great topic but I'm strugling with my Konnekt 8 - have replaced all caps in +/-15V power supply, phantom one and C575/576 (marked in red), still no luck, it doesn't powers up, and there is no 12V on that +/- convertor input, altho there is no shorts or bad fuses either, LD25 near firewire connectors lights up. Where to look next?

[Khron]

Re: TC Electronic Studio Konnekt 48 revival

Going by those voltage readings on the MOSFETs, looks like the digital supply is indeed switching, but the analog one isn't. They're some sort of simple self-oscillating designs (pretty sure they're identical to the ones inside the K48, just with different component designators).

The regulator over on the right edge of the board is the 1.8V one supplying the DICE core voltage - that seems to not be getting any input? That should be coming from the 3.3V rail - is yours functioning correctly? If anything, that's the "heart" of this design. It supplies almost all of the digital / logic circuitry, the DICE core voltage is derived from it, etc.

As in the case of at least two other K48's that passed through my hands (which were nearly instantly revived by replacing ONE capacitor), you might want to (also) check the two capacitors on the 3.3V rail, ie. C157 & C158.

[jons]

Re: TC Electronic Studio Konnekt 48 revival

Then, if I understand correctly, there is only 3.3V and 1.8V supplies for digital and no 5V? And center one is 3.3 right? Because it seems that for K48 there is different silkprint on board than on K8/K24 as I can't find those C157 & C158 on mine.
Edit: replaced those near Q59 - C517, C518, C422, C425 but still nothing, I suspect that most likely I damaged some hole metallization trying to unsolder old ones as that was very hard even with temperature boost on my crappy chinese station.

[Khron]

Re: TC Electronic Studio Konnekt 48 revival

Whoops, slight typo / brainfart, i looked at the designators upside down - i meant C517 and C518.

[vitaliistep]

Re: TC Electronic Studio Konnekt 48 revival

Hey guys, very interesting thread, thank you for sharing!
Does someone know where I can find a service manual for Konnekt 6?

[Khron]

Re: TC Electronic Studio Konnekt 48 revival

Long story short, no way. It was a pure stroke of dumb luck that u even stumbled across the one for the K48 (likely some negligence on TC's part). But especially now with the change of ownership and changing servers, even that's gone.

Might be more effective / constructive to describe your issues, though?

[vitaliistep]

Re: TC Electronic Studio Konnekt 48 revival

Thanks, I'm a happy owner of K6 for 8 years and luckily still no issues. I've bought used K48 recently too. While checking it and doing cleaning/maintenance (no problems so far), I found this topic and was just thinking about getting the service manual for K6 as well just in case

By the way you are experienced in electronics, but I also found a thread on Reddit with some interesting comments about K48 repair from a TC tech (danosaur), maybe it will be useful for someone.
https://www.reddit.com/r/audioengine...rface_to_last/

[Khron]

Re: TC Electronic Studio Konnekt 48 revival

No reddit account, and it won't show enough of the comments to find the one(s) you mentioned.

I still use my K48 as a crossover / monitor controller, as well as I/O expansion (even though that part is entirely unnecessary ). I do keep it powered on virtually all the time, because it (once again) takes a while to successfully finish booting up from cold - the 3.3v cap likely needs a refresh again, but I can't really be bothered. The thing's an utter PITA to take apart and reassemble...

[barbas]

Re: TC Electronic Studio Konnekt 48 revival

Here's a new share of the Schematic manual if somebody needs it again

https://drive.google.com/file/d/1-RE...w?usp=drivesdk

[vitaliistep]

Re: TC Electronic Studio Konnekt 48 revival

Hi Khron,

Noticed some issue with channel 3 preamp on K48: -20dB pad switch doesn't do anything. It doesn't bother me too much as it works on other 3 mic inputs, but can you tell me what it potentially is?

Thanks,
Vitalii

[Khron]

Re: TC Electronic Studio Konnekt 48 revival

Could be the switch itself, could be some of the transistors between that and the relay. I'm away from home for a couple days, and i can't day for sure.

[barbas]

Re: TC Electronic Studio Konnekt 48 revival

TC Schematics and Board Layouts (top/bottom) as well as service notes for most units are online again: Grab yours while you can.

https://service-tcgroup.tcelectronic...techserver.asp

Inside that, you can find:
https://service-tcgroup.tcelectronic...konnekt_48.asp
https://service-tcgroup.tcelectronic...onnekt-live/2/
https://service-tcgroup.tcelectronic.com/konnekt-6_.asp

Schematics, board layoouts, good info.

[vitaliistep]

Re: TC Electronic Studio Konnekt 48 revival

@barbas, that's pure gold, thank you so much!

[barbas]

Re: TC Electronic Studio Konnekt 48 revival

@barbas, that's pure gold, thank you so much!

It is!

[BlooRoom]

Re: TC Electronic Studio Konnekt 48 revival

My TC SK48 has started having booting problems lately. It doesn't power up immediately, the blue ring blinks for a couple of seconds, then it seems to try to power up when the blue ring stops blinking, and after about 10 seconds it starts up. Interesting, if I turn it off then and turn on after a while, it boots normally.

Reading this fabulous thread, I suspect it's just the dreaded C589 capacitor. I downloaded the pics and the schematics and one of these days it will go "under the knife". I will most probably change the C588, too while at it. Why not.

I'm going to use Panasonic low-ESR capacitors with 10V/105c rating. I think it will be alright afterwards. I also have a problem with one FW port working and I was hoping they put a fuse of some kind in there... but from this incredible thread I figured I'd have to replace the whole TSB chip, so that one will have to wait. I don't need two firewire connectors anyway.

Thank you so much for this great thread, chaps! Especially Khron, of course I didn't think the solution is [probably] that simple.

Khron, you [probably] saved me so much money, man. Thank you wholeheartedly for being so generous and sharing so much info about SK48 issues. Your blog is fantastic, too!

Cheers all!