[SOLVED] SMPS output flickering

Status
Not open for further replies.

ismu

Full Member level 2
Joined
May 12, 2009
Messages
145
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,298
Location
nil
Visit site
Activity points
2,340
in my Tecktronics TDS100c model internal SMPS is from Emerson , it has been damaged , its TOP244yn IC is gone bad[smoke is there near] , so i replaced with new one , after that out put is coming 3.3v but it will on at 2sec and off at 2sec and repeating ,i didnt check other sections may same issue ., what should i change .see the picture ..
 

Attachments

  • 20140921_150122.jpg
    228.4 KB · Views: 177

i think there is a problem with current sense section
 
Reactions: ismu

    ismu

    Points: 2
    Helpful Answer Positive Rating
can suggest where is the current sense laction in top244yn ic or any related components ?
 

check the optoisolator and high watt resistors or replace th optoisolator if you have.
 
Reactions: ismu

    ismu

    Points: 2
    Helpful Answer Positive Rating
where will be the high wattage res? which one?can u check below picture , i think opto is 817
 

Attachments

  • 20140921_150122.jpg
    1.4 MB · Views: 174

Hi,

have you cleaned the smoked part of the PCB properly? There might be slightly conductive residuals.
Or an old electrolytic capacitor,
or a lot of other reasons.


Klaus
 
Reactions: ismu

    ismu

    Points: 2
    Helpful Answer Positive Rating
yes , i cleaned well

- - - Updated - - -

in top244yn data sheet they mensioned reference design , can u refer that schematic and wich may be the resistor whch u have mensioed earlier? currently body is not with me ./
 

i suggest you to check all the resistors carefully (specially high watt resistors like R7,R8,R5 etc) and the diodes specially D6,D7 with multimeter
 
Reactions: ismu

    ismu

    Points: 2
    Helpful Answer Positive Rating
H all friends

i got the issue and now it is working fine , the problem was optocoupler has been damaged , i replaced it.

Thanks all [specially hamid159 ] for your valuable replay .

- - - Updated - - -
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…