guys i have an eotech 511 that i just got around to installing on my 20" ar flattop. Every time you fire off a shot the dot disapears and after a few seconds it comes back on. i dont think this is right so what should i do? buying a new one is out of the question right now do to so much needing to be replaced or repaired in my life right now.
I have had this issue with older EoTechs and IIRC this will be a battery contact issue. You can remove the battery contacts, stretch them, reinstall them and it should clear this issue.
EOTech has had issues with this in the past, and even some mil recalls.
The batteries are aligned with the bore, and the contacts are spring loaded. Too weak of springs, and when the gun recoils it causes the batteries to lose contact with the contacts.
This is why all my RDS’s are Aimpoints + a few other reasons like much longer battery life, no timed shutdown, etc.
dang i never thought of that. but it does make sense.You guys are good. is there any way to fix it permanently?
Send it to EOTech, let them fix it, and sell it. Then get an Aimpoint unless you are really stuck on EOTech, and in that case sell it anyways then get one of the models where the batteries are perpendicular to the barrel not parallel.
Contact Eotech and they might assist you with this but cannot guarantee it.
I rebuilt about 80 of the Model 552’s when I was in Iraq with the rebuild kits they supplied. This consisted of a new rubber piece (the one on the housing) plus new springs, contacts and washers. They also sent us new battery packs.
Once a battery pack is bad, you pretty much have to trash it. They cost 9.00 a piece and if I were sporting an EoTech I would probably keep a couple handy.
I have sent sights back to EOTech for warranty issues in the past and never had a problem… There customer service has been awsome. In most cases the issues were operator induced and they sent me a complete new sight even if the sight was used at the time I purchased it… Cant say as much for Aimpoint… limited warranty.
i don’t have problem with my eotech 511 and i love it.:D. The best thing you can do is to contact the eotech warranty department to see they can fix yours. And Go gon from there. You don’t want to fix it yourself. 
I had an Eotech issue (dots looked like check marks) and Mike Kroll at Eotech took great care of me. I recommend you contact him directly with any Eotech issues, as the company has revamped its customer service branch and is trying to be on top of any complaints or performance issues.
Michael Kroll (734-572-2176)
michael.kroll@L-3com.com
L3 - Eotech
1201 E. Ellsworth
Ann Arbor, Michigan 48108