Is my CR4 dead?


Full Member
Jan 31, 2011
Erie, PA
I have the CR4 plugged into the JRP 2 and the JRP is plugged into my computer, but the CR4 power light is not illuminating. When I try to program the CR, J-Runner prints "Xilinx Device ..... [NOT DETECTED]." Is it safe to assume my chip is dead? Is there any other way I can test it?


VIP Member
Dec 14, 2012
The only option for plugging the CR4 into a JR-Programmer is for the Rater to get the best boot times. lol. There is now power rail on that bus, as it is basically like plugging the post out wire and ground directly into the JR-Programmer. And that probably doesnt make much sense, if you dont understand how the exploit works, or computers with POST codes. lol. There are tons of guides on this, but short of an old CR3-lite, or Coolrunner derivitive there is no need to program it. Unless you are using an off brand chip, such as the ACE, and want to do S-RGH, RGH1.2 or Project Muffin, which dont help with a CR4. That being said, I have found these 3 mod options to be really cheap, and reliable replacements for a CR4 chip. That being said, I do like how much TX puts into their product development and testing, which makes the extra money worth it, if you are willing to spend it, or can even find the parts these days.