Review and repair of ALTERA Arria II GX FPGA Development Kit (DK-DEV-2AGX125N) - Page 1
Forum section: electronics / general

author: TiN
author_rank: Super Contributor
timestamp: August 27, 2015, 08:25:48 pm
content: In case someone might get interested,repair article and reviewof mid-range Arria II GX Kit.Board itself:Repair in progress, +2.5V power plane is shorted to ground somewhere (this power rail powers SRAM, Flash , EPM2210, LAN and some aux VREGs), so need to find short first by removing parts one by one...

author: TiN
author_rank: Super Contributor
timestamp: August 27, 2015, 08:29:06 pm
content: FPGA die little bit chipped in two corners, hope that's still fine.Will see after repair on power side.

author: marshallh
author_rank: Unknown
timestamp: August 28, 2015, 04:58:10 am
content: I have the same board, mine is also very slightly chipped in the corner though it still works fine. The die thickness is mostly wasted space, you really have to worry about the thin space on the side you can't see.

author: krivx
author_rank: Frequent Contributor
timestamp: August 28, 2015, 07:19:39 am
content: Is xdevs.com down?

author: TiN
author_rank: Super Contributor
timestamp: August 28, 2015, 07:26:40 am
content: QuoteSeems working ok here...MarshallhNah, it's busted. I'm aware of flip-chip BGA construction, but these chips are deep down as well.MAX II EPM2210 was a reason for 2.5V short, it's dead. Removed it - now all 2.5V, 1.5V, 1V, VTT supplies up and running.Onboard USB blaster works now ok too.But resistance on A2VCCA_PLL is 0.01 ohm, and that supply obviously not working. And A2VCCIO_B6A bank from +2.5V is shorted too, 0.2 ohm there.So it's bustReplacing FPGA would be cost unreasonable, so board can be used as fancy USB-Blaster now.

author: krivx
author_rank: Frequent Contributor
timestamp: August 28, 2015, 08:23:20 am
content: Quote from: TiN on August 28, 2015, 07:26:40 amThe main site is accessible, the link for the article on this board is not (on my end at least)

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 28, 2015, 08:35:38 am
content: Quote from: krivx on August 28, 2015, 08:23:20 amIt should be fix, not repairhttp://xdevs.com/fix/dk2agx125/

author: TiN
author_rank: Super Contributor
timestamp: August 28, 2015, 04:49:14 pm
content: Yep, fixed link.Final update, got power regs up and running , MAX II 2210 CPLD had shorted bank to ground, as well as some of its I/O. Removed with hotgun, 2.5v , 1.5v, 1.0v back online. It does take lot of patience to rework 14-layer PCB like this, solder melts really slowly.Worse newg, FPGA is cold dead. It's analog PLL power rail dead short to ground, and bank 6B shorted too. Removed all MLCC's to make sure it's not cracked cap causing short , so that's dead end here.It does not respond on JTAG either (tried both onboard blaster, which works now, and external one).Pity, I hoped to get Linux on FPGA , but seems that should wait. And ebay shows nothing for Arria's in this package so far, unlikely that I would be able repair this kit in cost effective way, unless some one here have spare EP2AGXxxxEF35 FPGA chipI looked at chips on FPGA die under x20 microscope, and those chips go deep down to bottom surface of die, where actual structures are diffused.P.s. any ideas welcome of what we could do with this boardI thought for a second to connect 1.2V 500Amp DC supply to shorted 2.5V PLL rail, and record a video of destruction happeningBut I'll let it sit a little for a while before this destiny comes.

author: SaabFAN
author_rank: Frequent Contributor
timestamp: August 29, 2015, 11:09:07 pm
content: I managed to kill my Max II board in a way you're describing your destruction-plan: Carelessly putting a 9V Battery with leads attached on the table, the next thing I saw was a tiny speck of smoke coming from the board, as something glowing red hot burned through the plastic before apparently breaking and becoming cold again.Unfortunately I had already sold my camera by that time, otherwise I would have recorded the (in the dark) rather pretty looking destruction unfolding when moving the battery-leads across the contacts.So be sure to make the room dark, get a battery with a lot more voltage than the device can handle and use a slow shutter-speed to get the glowing stuff on video

author: Berni
author_rank: Super Contributor
timestamp: August 30, 2015, 08:45:21 am
content: You might need a beefier supply than that. Sometimes shorts are very low impedance and sending a few amps in to the rail will simply make something get warm. This is how i often hunt for power rail shorts, just force tons of current in and feel around what part gets hot.So to actually make some pretty fireworks you may need quite a lot of amps. If you don't have a big brute of a PSU for it then a few rechargeable AA cells should get you 5 to 20A. Or if all else fails use a car batteryBut do be careful if you do that since they will give you more than 500A if you ask them to.