Saw this baby on eBay a couple weeks back, on auction, faulty. Boots up, but no Firewire activity. Reasonably common issue - routinely, the TI TSB41AB2 PHY-chip's toast.
While fully-working ones hover around 500eu (~550$-ish), i snatched this one for 184e shipped
I had been drooling after one of these gems ever since i started considering getting an audio interface.
Now, before getting on to the actual fault - this thing is CHOCK FULL of stuff, in addition to the abundant I/O options, "even" compared to my trusty Saffire Pro 40. Hell, it even has TWO friggin' transformers on the actual mainboard :p
Cap-wise, it's a literal hodgepodge, not really sure what to make of it. Hermei in the actual mains power supply, with possibly a Teapo on the primary (it's heatshrunk, but with a Teapo vent design). On the mainboard, there's one Panasonic NHG, a number of Nichicon HD and a pair of PS on the "secondary" power supplies plus a few 7mm-high ones scattered about, one fat Elna on each mic channel, and an array of Hitano and Elite pretty much everywhere else (signal coupling, i'd reckon).
The PCB layout / routing is indeed an engineering work of art. As the schematics indicate as well, there are test pads for literally EVERY friggin' signal. And i mean EVERY last ONE of them, i'm sure
I've lost count how many different ground signals/planes there are; analog/digital grounds are isolated with a resistor in parallel with a few diodes. Damn near brings a tear to the eye 
On to the actual issue and whatnot - upon the removal of the case, as well as the digital daughterboard, while investigating the area with the PHY, i noticed what looked like (uncleaned) flux residue on a ~1in radius around the chip, as well as most-definitely-NOT-factory soldering on the pins of the chip. That, plus the pad missing from underneith pin 16 (N/C, so no worries there) was a pretty dead giveaway that the chip had actually been replaced already.
Juuuuuust to be on the safe side, i extracted it, and replaced it with a brand-spankin' new one i had received but a couple days before the Konnekt itself. Soldered it back in, powered it up, plugged in the cable... (still) nothing
Well, sod it...
After first starting to search for some tech support contact data from TC, i noticed a code name/number on the main board, right underneith the silkscreened TC Electronic logo. What the hell, let's google it And lo and behold... 
[Edit: link broken, see attachment]
Now you don't see THAT every day... When's the last time the manufacturer of such a complex piece of gear had ANY sort of service data available?
Despite that, and pouring over the schematic for several hours, i took a couple days off, held a wee (late) birthday dinner and so on. Finally, tonight, i decided to squint at the schematic a bit more. Browsed to the sheet with the PHY... Saw the input supply voltage had an interesting designator, "5V_PHY", which then went into a 34063 buck-converter, which in turn, supplies the PHY with the 3.3v it needs. Ctrl+F, typed "5v_phy", first result was on the PHY page, then 3 on the block-diagram page, and then on the power supply sheet.
Hey, this thing's supplied from a totally isolated winding on one of the two "secondary" transformers. Hmm... Multimeter, diode test: the rectifier schottky, forward-biased, checks out fine (0.16v, for a 2A 40v diode - seems legit); reverse-biased, not so fine - around about 1v. That can't be right.
Unsoldered the diode, red lead on where its positive end was, black lead on the ground-lead of the associated cap - still 1v. Something's definitely fishy here...
Just for the hell of it, i started desoldering the pins on one side of the 34063, starting with CMP, simply 'cause it was the left-most one, on the side facing me. Second pin lifted was the VCC. Measured again, 1.4v - HELLO... Lifted the next two pins as well (ISNS and DRC), measured again - voltage drop rose above 2v in less than a second, and then OL - GOTCHA!
As a sanity-check, with the other 4 pins still untouched (including the GND pin), i measured the 4 pins i had lifted. VCC-GND shows roughly 0.96v, and ISNS-GND is around 1.4, neither of which, i'm quite certain, should be anywhere near that.
It's 6am right now, and i just wanted to get this "off my chest", as it were. Some teardown (or, actually, more like "(already) torn down) pics to follow tomorrow; already placed an order for a few 34063's, so... Now we wait
While fully-working ones hover around 500eu (~550$-ish), i snatched this one for 184e shipped
I had been drooling after one of these gems ever since i started considering getting an audio interface.Now, before getting on to the actual fault - this thing is CHOCK FULL of stuff, in addition to the abundant I/O options, "even" compared to my trusty Saffire Pro 40. Hell, it even has TWO friggin' transformers on the actual mainboard :p
Cap-wise, it's a literal hodgepodge, not really sure what to make of it. Hermei in the actual mains power supply, with possibly a Teapo on the primary (it's heatshrunk, but with a Teapo vent design). On the mainboard, there's one Panasonic NHG, a number of Nichicon HD and a pair of PS on the "secondary" power supplies plus a few 7mm-high ones scattered about, one fat Elna on each mic channel, and an array of Hitano and Elite pretty much everywhere else (signal coupling, i'd reckon).
The PCB layout / routing is indeed an engineering work of art. As the schematics indicate as well, there are test pads for literally EVERY friggin' signal. And i mean EVERY last ONE of them, i'm sure
I've lost count how many different ground signals/planes there are; analog/digital grounds are isolated with a resistor in parallel with a few diodes. Damn near brings a tear to the eye On to the actual issue and whatnot - upon the removal of the case, as well as the digital daughterboard, while investigating the area with the PHY, i noticed what looked like (uncleaned) flux residue on a ~1in radius around the chip, as well as most-definitely-NOT-factory soldering on the pins of the chip. That, plus the pad missing from underneith pin 16 (N/C, so no worries there) was a pretty dead giveaway that the chip had actually been replaced already.
Juuuuuust to be on the safe side, i extracted it, and replaced it with a brand-spankin' new one i had received but a couple days before the Konnekt itself. Soldered it back in, powered it up, plugged in the cable... (still) nothing
Well, sod it...
After first starting to search for some tech support contact data from TC, i noticed a code name/number on the main board, right underneith the silkscreened TC Electronic logo. What the hell, let's google it
And lo and behold... [Edit: link broken, see attachment]
Now you don't see THAT every day... When's the last time the manufacturer of such a complex piece of gear had ANY sort of service data available?
Despite that, and pouring over the schematic for several hours, i took a couple days off, held a wee (late) birthday dinner and so on. Finally, tonight, i decided to squint at the schematic a bit more. Browsed to the sheet with the PHY... Saw the input supply voltage had an interesting designator, "5V_PHY", which then went into a 34063 buck-converter, which in turn, supplies the PHY with the 3.3v it needs. Ctrl+F, typed "5v_phy", first result was on the PHY page, then 3 on the block-diagram page, and then on the power supply sheet.
Hey, this thing's supplied from a totally isolated winding on one of the two "secondary" transformers. Hmm... Multimeter, diode test: the rectifier schottky, forward-biased, checks out fine (0.16v, for a 2A 40v diode - seems legit); reverse-biased, not so fine - around about 1v. That can't be right.
Unsoldered the diode, red lead on where its positive end was, black lead on the ground-lead of the associated cap - still 1v. Something's definitely fishy here...
Just for the hell of it, i started desoldering the pins on one side of the 34063, starting with CMP, simply 'cause it was the left-most one, on the side facing me. Second pin lifted was the VCC. Measured again, 1.4v - HELLO... Lifted the next two pins as well (ISNS and DRC), measured again - voltage drop rose above 2v in less than a second, and then OL - GOTCHA!
As a sanity-check, with the other 4 pins still untouched (including the GND pin), i measured the 4 pins i had lifted. VCC-GND shows roughly 0.96v, and ISNS-GND is around 1.4, neither of which, i'm quite certain, should be anywhere near that.
It's 6am right now, and i just wanted to get this "off my chest", as it were. Some teardown (or, actually, more like "(already) torn down) pics to follow tomorrow; already placed an order for a few 34063's, so... Now we wait
).
TC Near device etc.
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