technika 32g22b

[t1412]

Hi fella's has anyone repaired  technika 32g22b,no backilght, i did replace the psu with a simliar one, backlight is working now,  has anyone repaired the psu, it's a tp-ms3463s, pb711.  before i order one thanks     

shaun

[Davy]

It's not the one with the power supply on the main is it? I've had the rectifier go on the inverter.

Dave

[t1412]

hi dave have you got part location you changed if possible thanks

shaun

[Davy]

Sorry I'm late.

No can't recall the placement numbers, as I remember looking at the board in situ the mains input is on the left, around the top middle is the inverter tranny, there is normally three paralleled diodes, side by side usually one goes s/c.  I've seen similar boards where there has only been two of them.

I use SB5100 diodes, I find are better than the ones they used, these being 5amp jobs and better rated, never ever replaced any of them to date.

I use to use the originals and one set came back twice every 14 months or so.... using SB5100 put paid to that, the set lives a few doors down, this is Technika used in the kitchen, the originals I think was SR types 303 or 505 - I could be wrong here.

Dave

[t1412]

Hi dave, there is 3 larger diodes, one has got a low forward voltage could be leaking under load  this is a hbr315 3amp 150v i'll change it see what happen, thanks

shaun
 

[Davy]

Hi Shaun,
These are schottky diodes so they will have a low forward drop 0.3v or less, there are time's when you have to lift em' in power supplies to check because they lob a resistor on the output end to keep them loaded... never seen this in inverters though.

They usually show leakage or s/c in both directions, you said HBR315, I've come across them they're rated 3 amp if I recall.  A SB5100 will do the job with ease.

If you are really stuck just to try.... try a UF5402 or higher in, these are 200V ultra fast 3 amp DO NOT use the 1N5402 they will  blow.

Dave