I'm repairing owon pds5022 where the power supply is bad. The U3 chip is
burn beyond any real markings. It is 5 pin smd, SOT-25 package.
I've drawn the schema on paper and it looks like pin3 is input ( fed via
resistor), pin2 is ground, pin1 could be feedback. Pins 4&5 are
connected together and act as output, there is also connection to pin1
to connector with small condensator and inductor.
The markings are so small that I cannot read them even with magnifier
glass (I'm getting old:-( ) , need stereomicroscope to read them.
The U3 could have markings 510B but cannot tell if that's correct.
The B can also be some manufacturer logo, code could also be upside down.

I've ruled out a couple smd regulators ( Torek brand ) , any idea what
component could really be ? Owon has not answered to my query.

ismo

On 28/01/2014 15:56, Ismo Salonen wrote:
I'm repairing owon pds5022 where the power supply is bad. The U3 chip is
burn beyond any real markings. It is 5 pin smd, SOT-25 package.
I've drawn the schema on paper and it looks like pin3 is input ( fed via
resistor), pin2 is ground, pin1 could be feedback. Pins 4&5 are
connected together and act as output, there is also connection to pin1
to connector with small condensator and inductor.
The markings are so small that I cannot read them even with magnifier
glass (I'm getting old:-( ) , need stereomicroscope to read them.
The U3 could have markings 510B but cannot tell if that's correct.
The B can also be some manufacturer logo, code could also be upside down.

I've ruled out a couple smd regulators ( Torek brand ) , any idea what
component could really be ? Owon has not answered to my query.

ismo

Owon meant nothing to me so Owon AND oscilloscope in google/images
threw up someone's fairly hi-res pic of inside of another model
http://www.electricstuff.co.uk/owon_...illoscope.html
any similarity in ps section ? worth a try using a device type from that
one, if all else fails
Is Owon a rebadge of some other make? again google/im for more general
storage scopes, may through up another maker name and model, same
appearance though.
A USB microscope is a fairly cheap these days useful addition to a
repairman's toolkit

The scope can be seen e.g here http://www.saelig.com/product/PSSA002.htm
.. Don't know if its is rebranded something but they do have own pages at
http://www.owon.com.cn/main.asp.
Pictures of power supply are at

bottom side ( where burnt U3 is )

https://skydrive.live.com/redir?resi...t=photo%2c.jpg

and component side
https://skydrive.live.com/redir?resi...t=photo%2c.jpg

Hope these help identifying it.

br
ismo

On 1/28/2014 4:56 PM, Ismo Salonen wrote:

Owon has not answered to my query.

At the moment the chinese are celebrating new year.
In china it is big, compare it with Xmas in the us.
Every one is visiting there family.
Don't expect an answer in 10 to 14 days.