RAMBO 1.2 static issue fix!!!

[johnoly99]

Guys, please read the blog post on our site. Remember, this only accounts for RAMBo 1.2's, NOT earlier 1.1 or 1.0's, and we have NOT been shipping since Monday to wait for these fixes to arrive. So, if you've got a machine out there, please don't hesitate to email us, and we'll get you fixed up

John

http://seemecnc.com/blogs/news/12116989 ... -patch-fix

[Eric]

I was curious, so looked at the Rambo v1.2 schematic. The fix-it jumper just connects the USB ground to the ground the rest of the board uses.

[KaibutsuX]

I just sent an email to seemecnc today about my board not connecting. The description from the blog post sounds exactly like my situation so I guess I will start disassembling my board.

Thanks for the info.

[Eaglezsoar]

That explains a few things. One user in Arkansas has just sent in his board for the same reason.
Now it makes sense.

[enggmaug]

I sent am email on Feb. 6th, but still didn't receive any reply... probably a mistake.

Do you guys know where can I find an exact description of the fix ?

[Eaglezsoar]

I sent am email on Feb. 6th, but still didn't receive any reply... probably a mistake.

Do you guys know where can I find an exact description of the fix ?

It's listed on the first thread of this topic.
John gave this link: http://seemecnc.com/blogs/news/12116989 ... -patch-fix

[enggmaug]

How could I miss it ?

tx !

[enggmaug]

OK, I read the link.

It seems that the fix is not just a wire strap, but from the pictures, it looks like there is a component inside it, maybe a diode, a resistor, but definitively a dipole.

Does anyone know what is it inside ? I want to do the fix myself, as I probably already have the component at home, plus I live in Europe, plus seeMeCnc did not reply my email for 2 weeks.

[mhackney]

A couple of thoughts:

Contact Ultimachines - the RAMBo's manufacturer and explain you are in Europe and want to do the repair

SeeMeCNC is usually very good about getting back to emails, if you haven't heard in a few days, email again. Don't just send 1 email and assume it got through. Follow up with another one (or two)!

cheers,
Michael

[Eaglezsoar]

The problem that is being fixed is that when they manufactured the cards they kept the ground area for the USB separate from the ground area from the rest of the card.
The fix simply ties the two ground areas together. That wire jumper contains this part: http://www.mouser.com/Search/ProductDet ... 0026D580DL
Their intent was to reduce noise on the USB side but in doing so they made it extremely susceptible to damage from static. Tying the grounds together allows any static
buildup to be discharged through the power supply. All the previous Rambos had a common ground then someone had a bright idea to separate them, it apparently was
not too bright of an idea after all. I do recommend to get the official patch kit because you may void the warranty if you use home brew parts plus why should you pay
for something that you can get for free.

[enggmaug]

I do not have varistors at home... ok, I'll try sending another email.

Thanks guys.

EDIT > I did that, and it's on its way. USPS is a bit slow, though... but well, it's not like I cannot print in the meantime.