10-05-2011 04:43 AM
Hello, I bought an Atlys board a couple of days ago, well this morning I broke the board, it was my fault, I tried to put in a case that was too small and the Adept USB2 plug had attached a cable which because sollecitations, teared the Adept USB2 port apart, to say the truth I didn't expect the USB ports to be so fragile..... but anyway... it happened!
I tried to resolder the USB port, but with no success... I think pins are too small and I believe this is a work that requires either some special high precision tools, or an infinite amount of patience.
Further informations about the accident: the USB port that broke was the so called "Adept USB2" (Config & data). it is used for the Xilinx Adept program which can test the board, and transfer files as well as doing high speed communication.
Unfortunately I have no warranty for this board, I bought it from ebay and I think cannot repair it without spending a lot of money I fear...
Alternatively I saw that there is still a possibility of program the board using JTAG cables, or by USB HID stick.
My question is: how much compromised is my board without the USB2 Adept port?
Should I buy a new one?
Should I try to program/configure it through JTAG cable (unfortunately I have no JTAG cables) or even using the
USB stick memory methods?
I'm new to FPGAs in general, and maybe I could still use my board without problems.. so I'm just asking..
Thank you very much
10-05-2011 05:21 AM
If you live in an area with an electronics manufacturing industry, take the board to a circuit board assembly house. There will be board rework technicians who can help you. You may need to provide replacement part(s) for the rework.
If you live out in some rural area, contact Digilent (the board's manufacturer) and ask for help. I'm sure that you can send them the board for repair and re-test -- for a fee, of course.
-- Bob Elkind
10-05-2011 12:04 PM
I'm not familiar with this board, but from looking over the User Guide it looks like they have a header that would be compatible with one of the Xilinx Programming cables and could be your alternative to using USB. With JTAG access you should be able to program the FPGA and get a majority of the prototyping functionality programming via iMPACT.
I'm not sure whether you can get a cable, another used board, or a repair cheaper. Seems like all three options could work.
10-05-2011 04:44 PM
There aren't very many compelling reasons to use the Adept port if you have a JTAG adaptor (FPGALink is good though!) but it shouldn't be too difficult to rework the board if you're good with a fine-tipped soldering iron or have access to a friendly technician with one.
I've got an expensive Virtex-5 board on which I busted the USB port within minutes of opening the box, then ripped up a PCB track while trying to rework it with a hot air tool that wasn't hot enough, and eventually fixed it with some thin wire wrap wire, even though this would have ruined the integrity of the differential pair. Still works great! :)
10-06-2011 05:46 AM
I have only 2 solutions left (since the memory stick solution seems not to work...) either repairing the port my self or buying a JTAG cable....
This morning I tried to repair the port myself... I found out it only needs 3 pins out of the typical 5 pins for micro USB.. that may make things a lot easiers.... I soldered the usb port on the board (and used some strong glue), the pins are connected on the pads... but still not soldered... only GND seems to make some contact... the other 2 useful pins (D- and D+) sometime work and sometimes don't (I'm doing continuity test with the Cypress MCU input pins which USB signals are directed linked to)
10-06-2011 02:07 PM
If you can't make a good solder contact with the pads, or if the pads/tracks are broken, try using very thin insulated wire to patch to the MCU's pins. There's not a lot of pin exposed to solder to but it is possible. Alternatively, you could try scraping off a bit of the solder mask with a scalpel if enough of the USB traces are on an exposed layer.
10-06-2011 02:22 PM
I do my own board rework. My soldering station has swappable tips and is temperature controlled. It costs about $1K. And I have finest (thinnest) gauge solder, liquid flux dispenser, cantilevered illuminated magnifying glass, and a steady hand. And my bench is completely grounded against static.
This is all amateur stuff compared to a professional rework station at a board assembly house.
Working with fine-pitch parts and a fine-pitch PCB is not easy. You need to know what you are doing, and you need good equipment -- or you risk damaging your board further.
If you are using a $100 soldering pencil with a solder spool for relays and switches, you might consider seeking help. What might take you hours and several re-tries might take a professional tech 5-10 minutes, and the results would be 'clean'.
Just a suggestion...
-- Bob Elkind