I purchased the SHARK cordless hand vacuum,18 volt SV779Z 14 from Walmart and mailed you its product registration on Nov.3,2010. As I was vacuuming my kitchen countertop ,there was a big bang and it stopped all suction. Walmart told me to get in touch with you since they did not have any more to exchange. I have the sales ticket and did register the product as mentioned before. I need to know what I can do to get a replacement since it was under guarantee. Thank you! Robert Schwarzenberger 255 Calle Escada Santa arosa Beach,Fl.32459

SOURCE: Suction

Might be the hepa filter needs cleaning? This is located in the housing on the side of the cleaner at the bottom (see your manual to find it). It is a big spongy ring which Dyson say you should remove once a month and wash in warm water. Dry off and replace in cleaner when completely dry. I've found this works and the suction is like that of a new machine!

SOURCE: Rainbow E Series Suction Problem

Being an E series some have a corrgated filter in the top, there is also a filter on the back. Could be a motor problem, not turning as fast as it should, in which case you will have to replace the motor. You might check, some had a 10 year warranty on the motor. If you are the original owner and only have had it 5 years, then it may be covered.

SOURCE: Changing A Belt on Vacuum

http://geeksquad.fixya.com/ThreadView.aspx?prdid=0&thid=656349
Generic problem for all Vacuums
Changing a Belt on Vacuum
Posted by cnjk on Jun 08, 2008
Can you give me directions on changing a shark Euro-Pro UV219CS vacuum belt?
Thank you.

Hello,
I would advise you to ALWAYS to FIRST UNPLUG YOUR VACUUM before beginning any service procedure. The Shark vacuum cleaner belt is a side driven belt and you need to remove the bottom plate and remove the belt and place the new belt on the pulley side of the brushroll and make sure the ends are the same, insert the brushroll and then use a belt puller or screwdriver with a bend on the end and then stretch the belt onto the motor pulley and the track it in a straight line, replace the bottom plate. If you need further assistance please fee free to contact your local vacuum cleaner dealer in your area. So feel free to contact your local vacuum cleaner dealer with questions. So if you need further assistance, please feel free to contact your local vacuum cleaner dealer in your area or in the yellow pages, or contact the factory phone number or website to further assist you with your questions.
http://www.sharkvac.com/ Customer Tech Support 1-800-798-7398
These are the other brands that use the same tech support line
Shark / Euro-Pro / Infinity / Bravetti / and Fantom
http://www.fantom.com/ Customer Tech Support 1-800-798-7398
Hours are Monday thru Saturday from 9:00 AM to 6:00 PM (EST)
Thanks, Don the Vac Man
Go Ahead. Use Us.

SOURCE: Infinity Shark Vacuum

I don't have the manual for the shark Infinity vacuum, it's purple.

SOURCE: dyson 18 losing suction

Check the HEPA filter if it has one. This bit of foam gets clogged over time and significantly reduces the suction especially if you've been vacuuming a lot of very dusty areas i.e. dust from building work etc. Just wash the filter with lots of water and leave to dry before reinserting.