X301T modchip not communicating with JTAG

Started by J, 11. Oct 2009, 16:55

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J

You know I was trying to make modchip on VIP 1216 but I failed, so I'm trying to modify X301T. So I've soldered modchip with LEDs to box enabld JTAG, replaced BooterCE I haven't patched Win trust model because when I was trying to patch it program gave me error but it useless form me and I've enabled USB and other stuff. I start the box yellow LED goes on for around two seconds then red LED is on. And box is trying to download firmware. Yellow led indicates only reset because when I unplugg the modchip from JTAG LEDs are doing the same thing yellow and then red. Modchip is programmed correctly and wires are good too I've checked them. I've read in some readme that was with compiled stuff and source for modchip that it should be connected like this:
TDI PC0
TCK PC1
TMS PC2
TD0 PC3
but on schematics, JTAG is connected to PD0... So this is a bit confusing.
What should I do to make the modchip work with my X301T
(Sorry for my bad English i hope you understand what kind of problem I have)

mce2222

did you wire up the jtag enable trace on the CPU ?
the x301 has jtag disabled and the jumper to enable it is not connected, as it was an early x300t models.

something like this is needed
http://www.t-hack.com/wiki/index.php/File:Pirelli_jtag_soldering.jpg

J

Really ? That stupid jumper is not working well that would explain everything, now that I'm looking at that jumper you're right there is a rezistor missing in there. Damn I'm not very good at soldering and I haven't got right equipment to enable it on CPU, but if I add that missing rezistor there it should be working right?   

is0-mick

Maybe you could meter between where the resistor is missing to the point on the CPU chip to make sure that there is a connection to there.

Mick

J

Yes thats first thing I've done, it's connected. I saw in pictures in Wiki that there should be that rezistor with number 103 on it. So I'm gong to check what those 103 are and then I'll let you know if I managed to get the box working.

mce2222

on x301t not only the resistor is missing but the complete wire that connects the resistor to the cpu is missing as well !
you can see it on the PCB because they did not rearrange the wiring, so there is an empty space.
check this image:
http://www.t-hack.com/wiki/index.php/File:X300-jtag-rev05.jpg

that is from a x300t rev5 where the wire is still there (colored red)
you will find that it is missing on your board.

is0-mick


Yes thats first thing I've done, it's connected. I saw in pictures in Wiki that there should be that rezistor with number 103 on it. So I'm gong to check what those 103 are and then I'll let you know if I managed to get the box working.

1 0 3 = 10k ohm
you take the first two numbers, then the 3rd is the multiplier (number of 0's to follow)
1 0 000 ohms = 10k

Mick

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