Voltage regulator

[Bip38635]

I hope I'm doing this the correct way. I'm new the the forum and have a stupid question. I'm working on a Vizio vx42l, the u33 regulator is bad. Is there a regulator I can buy for this application that comes ready to install, and if so where can I get it. I've been looking at different products online and am more confused after looking. The part is a 3 pin regulator 1117 input voltage is 5 output is 3.3. I don't know wattage or if that even matters. Please help.

[retiredcaps]

Re: Voltage regulator

II'm working on a Vizio vx42l, the u33 regulator is bad.

Ask the moderator to move this to the TV troubleshooting section.

My sig file below contains hints/links how to test a voltage regulator. The video includes examples of ordering from digikey.

[mariushm]

Re: Voltage regulator

The 1117 is the "family name" of a type of regulator that's very standardized and it's made by several companies.

I've actually watched a video on Youtube where the guy was replacing that exact regulator, U33 :

http://www.youtube.com/watch?v=cNFzB...ture=g-all-lik

His TV has the same issue.

digikey.com is a good online store to buy from, you just have to go to low drop regulators and select something with 1117 in them and adjustable (not factory fixed to certain values) :

He used this one: http://www.digikey.com/product-searc...=497-1229-1-ND

You want the one in the middle, as the first is a minimum quantity and the other is for supplying you the parts on a special reel which costs money.

These would also work just fine:

http://www.digikey.com/product-detai...ICT-ND/1301524
https://cdn.badcaps-static.com/pdfs/...851427662f.pdf

and if you'll search for 1117 on digikey you'll find tens of chips that are also compatible.

Just get one that can do current output 1A or more. All the above do.

[Bip38635]

Re: Voltage regulator

Thank you all for the help.

[retiredcaps]

Re: Voltage regulator

If anyone is wondering why I don't/didn't provide exact links to parts in my how to test a voltage regulator post, here are some reasons which I have seen happen on this forum

- that part could be out of stock at some future
- the supplier may not carry it in the future
- the supplier may go out of business
- people from around the world may face high shipping costs, taxes, etc and prefer alternatives
- people may have accounts with favourite distributors or go to local store
- there may be a cheaper, but just as good alternative

[MisterD]

Re: Voltage regulator

I hope I'm doing this the correct way. I'm new the the forum and have a stupid question. I'm working on a Vizio vx42l, the u33 regulator is bad. Is there a regulator I can buy for this application that comes ready to install, and if so where can I get it. I've been looking at different products online and am more confused after looking. The part is a 3 pin regulator 1117 input voltage is 5 output is 3.3. I don't know wattage or if that even matters. Please help.

What is the voltage on Pin 1 ? U33 is an adjustable regulator.

[budm]

Re: Voltage regulator

See post 27, 29 the the list of 1117 series regulators: Adjustable and Fixed output.
https://www.badcaps.net/forum/showth...t=23123&page=2

[MisterD]

Re: Voltage regulator

I hope I'm doing this the correct way. I'm new the the forum and have a stupid question. I'm working on a Vizio vx42l, the u33 regulator is bad. Is there a regulator I can buy for this application that comes ready to install, and if so where can I get it. I've been looking at different products online and am more confused after looking. The part is a 3 pin regulator 1117 input voltage is 5 output is 3.3. I don't know wattage or if that even matters. Please help.

What is the voltage on Pin 1 ? U33 is an adjustable regulator. I'm thinking your U33 is good Input 5V Output 3.3V and Adjustable Voltage on Pin 1 is probably around 2V, I'm fairly new here myself so anyone else have any advice???

[budm]

Re: Voltage regulator

This is the way to figure out if the adjustable regulator is good or not:
Notes: we are looking at the regulator with the Big tab up (the big tab is tied internally to the center pin).
Adjustable regulator will have two resistors attached to it, one resistor (Rfb) is between pin1 and pin2, another resistor (Rg) is between pin1 and ground. Pin3 is an input pin.
The voltage between the Adjust pin (left pin) and the center pin (Pin2, output) will always be 1.25V +/- 2% (this is the precision voltage reference), if it is not, it is bad.
To figure out what the output voltage should be: measure the voltage between pin 1 and ground and add 1.25V to that number, that is the output voltage on pin 2 but you have to make sure you do have 1.25 between pin 1 and 2 as noted above.
See my Voltage calculator spreadsheet here, post #6:
https://www.badcaps.net/forum/showth...417#post273417

[freakaftr8]

Re: Voltage regulator

This is the way to figure out if the adjustable regulator is good or not:
Notes: we are looking at the regulator with the Big tab up (the big tab is tied internally to the center pin).
Adjustable regulator will have two resistors attached to it, one resistor (Rfb) is between pin1 and pin2, another resistor (Rg) is between pin1 and ground. Pin3 is an input pin.
The voltage between the Adjust pin (left pin) and the center pin (Pin2, output) will always be 1.25V +/- 2% (this is the precision voltage reference), if it is not, it is bad.
To figure out what the output voltage should be: measure the voltage between pin 1 and ground and add 1.25V to that number, that is the output voltage on pin 2 but you have to make sure you do have 1.25 between pin 1 and 2 as noted above.
See my Voltage calculator spreadsheet here, post #6:
https://www.badcaps.net/forum/showth...417#post273417

Budm that is spectacular information! I was always trying to figure out the formula. Thank you!