Help with J-Tag on DIT7421/05

[verg0]

Hi, im new to this forum and would like to have play with this box can someone help me get the J-Tag to connect my DIT7421/05?, as i dont know where 'ALL' the resistor packs go?

If anyone can help please post a pic, im sure other people are haveing the same problem as me, thanks

Verg0

[is0-mick]

Maybe have a look at the pictures of the board in the howto. If the resistor packs are missing they will be right next to the jtag connector.

I have a DIT7421/05 and the resistors are there on mine...

Mick

[verg0]

yes some of the packs are missing... have you got a good picture without the wires solderd to the board as i could see if there is any more missing under the wires?

thanks again

Verg0

[is0-mick]

Hope this helps.. its the best pic I have here atm....

3331 and 3332 are the ones which I think are missing on your box. They are 10k x 4 packs.

Mick

[verg0]

Thanks Mick

Ive attached a picture of what should be needed now.

Ill try it later on and post here if it works

[warrmr]

I had that exact same problem on my box when i started, If you look a few threads down theres one started by me http://www.t-hack.com/forum/index.php?topic=327.0 on the second page there is some info on what the resistor packs you may need and where to wire them to.

I never did get this resolved for 2 reasons

1) the resistor packs are so small you need to be a god a surface mount soldering
2) the tip on Neos soldering iorn was to big and was cheap and started to disintergrate with the flux in the solder.

We had started modding my box while neo's was in the post when we realised how easy it was to get the one with all the chips and resistors working i baught another one off ebay it made things alot easyer.

Hope that gives you some advice on what you need.

I would get you some nice macro shots of the JTAG on my new board but I think we hot glued over the solder points to give them strenght. if i have some before photos kicking around i will post them

EDIT: I just looked at my box and we have glued over the resistor packs to hold tht solder joints on the jtag still. Also the 2 boxes i have are the same model and same revision but one has the modem and one of the usb chips omitted that is the one we couldent jtag.

[is0-mick]

Just an alternative on this....
The resistors are just pullup or pull down 10k ones.
You could solder them direct to the wires coming off your jtag connector..

So like this

Code: [Select]


||||| <--jtag connector
|
+--/\/\/--3v
|
|
pc



assuming that the original resistor was pulling that pin up to 3v3.

If the small sigle resistor by itself is only 1 ohm (I haven't checked) then you could just link it with a small piece of wire....

Mick

[is0-mick]

OK I've had a sleep on this.
I haven't tested this but it should work fine.

1) bridge the single resistor (1ohm) with a piece of wire or solder blob (don't forget to bridge the jtag enable jumper).
2) wire up your chip to the jtag
3) take a 10k ohm resistor from each jtag pin on the atmel to the 3v3 supply on the chip. (solder to the chip legs or mount on the pcb)

Heres a small pic of what I'm suggesting.

If this does not work, you may need to connect a 10k to pin 1 of the jtag going to 3v3 and another 10k on pin 11 of the jtag going to 3v3.

Feedback welcome!

Mick

[verg0]

Ok Mick ill try it, I haven't received my chip from Hong Kong yet, but I was going to test it with my Wiggler jtag just to see if I had connectivity for the wiki.

Ill let you know as soon as I can

Thanks for your reply its most appreciated


Think I'll have to put reset wire in the old place as there has been quite a few components omitted from the usb section of the board...

[Plasma]

Hey folks I realise this is an old topic hopefully someone will reply to me.

I just picked up a BT Vision and am VERY interested in modding it to ...... well do something, can't believe BT have it locked down so far as its useless without an account and internet connection (well i can but that's by the by).

I'm not a modding noobie by any stretch as far as mod chips are concerned, and have a few programmers, (USB Adtechnic, Serial Elvis, a random WinPicPgm programmer and a JTAG infectus). I'm an amateur programmer but no where near in your league! I've been looking at getting an ATMEGA8 from FleaBay etc, but was wondering how I identify the hardware in my box to enable me to wire the chip in.

On the back it says DIT9719/05, came without a hard drive (which I've now fitted) and have got it to the "C01" error I think thats where its got the OS on it but can't connect cause I have no account. After inspecting my hardware the 3331 and 3332 and solo resister packs are present, I guess that's a good thing!

*EDIT* Seems I may have posted in the wrong section but durrrrr I'm new .. I apologise!

I'm gonna keep googling but if anyone can give me any pointers that would be great.

Cheers

Plasma

[is0-mick]

just read the HOWTO in the hardware section. Most things are explained there.

Mick

[sparky2]

Hi Mick, on my diagrams there are no LEDS showing, do you have an update circuit diagram that I can follow- TA

[Herman]

assuming you mean the led's on the atmega. They are not compulsary and not required for modchip to work.  However, they do come in usefull if something isnt right as they indicate if they jtag detected cpu correctly, patched correctly and reset.

[sparky2]

  Thanks Herman, Do you have a circuit for inserting them next to the 'atmeg8' chip as I am about to insert everything into the veroboard. 

[janekdrukarz]

hi
i`ve got philips 7421/05.
another mother board, can anybody tell me where is jtag.
regards

ps. sorry small speak english