Anyone have the schematic of JTAGICEmkII?

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Hi, guys,

My JTAGICEmkII was broken by me a long time ago and since then I always use ISP for my AVR projects, but now I need to use AVR32 and I have to repair my JTAGICEmkII. I found out that the VTref pin on the JTAG 10pin connector of JTAGICEmkII just get 29ohm to GND, so I must have broken the interface voltage reference protection diodes or capacitors. The PCB of JTAGICEmkII has 4 layers, so I really need a schematic to make sure I have all the connection on VTref pin.

Anyone have ideas?

Cheng

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The schematics is supposedly Atmel confidential.

Do you have the older (2003), or a new (2006?) PCB version? The new
one can be easily recognized by the additional LED close to the USB
connector (which will light in green as soon as the USB interface is
activated). The new one appears to have a lot more protection
circuitry (one protection diode array from Little Fuse, and a couple
of analog switches from Maxim). So far, I've only seen one failure on
the new ICEs, and that one "cured itself" after power-cycling the ICE.

In contrast, we've had at least one broken ICE of the older PCB make,
and it turned out to be one of the three Maxim level shifters that was
burned. Try to carefully unsolder them (in my case, it's been the
middle one out of the three), you can temporarily use jumper wires to
verify everything is well afterwards. Just refer to the Maxim pinout
to see which contacts to connect to, and use a target circuit that is
powered with Vcc = 5 V (which matches the ICE's internal voltage, so
no level shifting is needed). Once you found it, order the respective
samples from Maxim, or if you're an Atmel customer, ask your friendly
FAE about them.

As these level shifters are dual-powered (internally by 5 V, and with
Vtarget as the low-side reference), I guess the low-resistance patch
on your Vtarget pin is just an artefact of the broken IC.

Jörg Wunsch

Please don't send me PMs, use email if you want to approach me personally.

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Hi, Jörg,

My JTAGICEmkII is 2003 version.

I have ordered the samples for that three level translator from MAXIM. But there are also at least three 0603 capacitors on that net. So I'm not sure if it's one of three ICs been broken.

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I got a 14Kohm on pin5 of MAX3379 (the left one) which is directly conencted to nSRST pin on the 10pin JTAG. The rest 3 input pins and 4 output pins on MAX3379 (pin2,13 as TMS, pin3,12 as TCK, pin4,11 as TDI and pin10 as output of nSRST) all have about 3Mohm.

I also got a 14Kohm on pin5 of MAX3391 (the middle one) which has no connection to JTAG connector. all the rest 7 I/O pins got about 3Mohm.

I also got a 32Kohm on pin5 of MAX3392 (the right one) which is TDO input, and a crazy 125ohm on pin10, which is the ouput of this TDO.

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Jörg, can you please measure the resistances of your level translator I/O on your working JTAGICEmkII? So that I can have a reference to find out which one is broken.

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I guess measuring ``resistances'' won't help you much. Remember, these
are semiconductors, so their resistances are highly non-linear, and
depend much from the voltage applied. So unless our multimeters were
the same make (and apply the same voltage), the figures will vastly
differ.

I applied Vtarget externally from a lab power supply (5 V). The ICE
draws about 600 µA on Vtarget. If that's dramatically more in your
case, feel lucky: the broken chip might heat up from that, so you
can identify it. (I'd limit the current supply to about 100 mA.)

After applying Vtarget, all of the non-GND pins get some measurable
voltage. For pins 1, 3, and 5, it's around 200...300 mV. Pin 6
goes up to about 4.5 V. For pins 7, 8, and 9, this appears to
depend on the ICE state. Most of the time, I see them around a
few hundred mV either, but I've occasionally also got about 2.5 V
on those.

Jörg Wunsch

Please don't send me PMs, use email if you want to approach me personally.

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I just removed the MAX3392 (the right one) and then wired that 4 pins, and then tried with a 5V AVR, and it worked!!!

Now the pin1 of the rest MAX3379 and MAX3391 give 190Kohm, which I think should be correct. But their pin5 still gives about 190Kohm instead of correct 3Mohm, strange...

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ok, I will try to measure this VTref current.

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ok, forgot that I just removed the wires...
I can wait until I get new MAX3392 and solder it onto the PCB.

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Thanks, Jörg.

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I still wondering why the TMS, TCK and TDI pins are designed to be bidirectional on this interface. They just needs to be output from JTAGICEmkII, but the MAX3379 (the left one) has 3 pins for them...

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just measured the resistances between pin1 (V_target)and pin5 on the rest 2 ICs, both give me about 14Kohm, all other pins gives me about 3Mohm, this's not good...
probably I need to replace all 3 ICs.

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ISTR I also had to replace the MAX3392, but it's been a while ago, so
I'm not sure anymore. The other two level shifters were not affected.

No idea about the seemingly complicated pin routing, I wondered myself
about it by that time.

Jörg Wunsch

Please don't send me PMs, use email if you want to approach me personally.

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I just replaced all 3 ICs and the MKII is working now.

I measured the removed MAX3379 and MAX3391, they seems not broken at all, so probably it's just the MAX3392 which is broken.

The pin 5 (nSRST) of MAX3379 is connected with pin 5 of MAX3391. And even after I removed these ICs, the resistance of this nSRST to GND is still about 192Kohm, and now after soldering the new ICs, it's the same 192Kohm.

Anyway, my lovely JTAGmkII is working!!!

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> ...so probably it's just the MAX3392 which is broken.

That's what happened to my ICE once, too. The '3379 and '3391 were OK,
only the '3392 broke.

Jörg Wunsch

Please don't send me PMs, use email if you want to approach me personally.

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I just found out another problem, when I connected my JTAGICEII to my PCB and turned my PCB power on but with JTAGICEII power off, and if I press the reset push button on my PCB, I can see that the power consumption of my PCB increased about 150mA!!! But the JTAGICEII is not broken, it can still work afterwards.

I'm not sure if it's something wrong with the level translators that I replaced or if it's the design bug in the original JTAGICEII.

The datasheet of MAX3372E - 3393E said: "VL = +1.2V to (VCC + 0.3V)", so if JTAGICEII is not powered, then I guess VCC is 0, and when the JTAGICEII is connected to your powered PCB, then VL is higher than VCC, which is wrong!!!

can anyone test your own JTAGICEII to see if you also get strong current??

Cheng

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Uh...

It actually says not to do this in the help file for studio.

so sorry but no.

Darren

----------------------------------------------------
Those whom the gods wish to destroy
they must first teach to use c
----------------------------------------------------

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ok, I never know this, this may be how my JTAGICEmkII got damaged in the first place.

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Hello There
I have same problem - after crash of JTAG MKii and restore of my USB ports on notebook i see the JTAG mkii in Avr studio - but there is not working the jTAG and ISP signature read - i hope it's caused by burned MAX chip.

How i can test which one is broken? I have oscilloscope and multimeter.

THank for your help

J

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Today i have replaced all 3x voltage converters - but my jTAG isn't still working ;(. Have you any other idea how to solve it?

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Hi, my jtag ice was damaged, because of shorting two lamella of flat cable. AVR studio could read the target voltage, but could not read and program target device. After some sort explore working I could repair my jtag ice to solder together pin2 and pin3 of max4712. Jtag ice has two max4712. Pins 1 and 16 of my damaged max4712 situated close to pins 8 and 9 of SP720ABG.

Now  jtag ice works correctly. Later I will by new max4712 to replace it.

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I have 3 jtagicemkII. How bout a nice picture please?

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