Olevia 337-B11 Need some help with this one please!

[Tvbob]

Re: Olevia 337-B11 Need some help with this one please!

With the set in standby, The 5volt supply bounces around and the power led flashes. With the (power) module removed from the module and powered up unloaded. The 5volt standby is still unstable. And the raw b+ is 163vdc. There are 4 0ptic couplers in this power supply and all caps are in spec, and there no shorted semiconductors Anyone know of an schematic for this board? (AEP016-37 thanks

[budm]

Re: Olevia 337-B11 Need some help with this one please!

There are 3 caps (2 small and one large) by the IC1 5v standby. Try heating them up with the hair dryer for 2~3 minutes, then supply the 120v and see if the 5v becomes stable.
Any pictures of your board? Bad cap can look normal.

[Tvbob]

Re: Olevia 337-B11 Need some help with this one please!

They have been changed before me and are in tolerance. I don't know if they are the right value. Thanks

[budm]

Re: Olevia 337-B11 Need some help with this one please!

They look much bigger than the one as shown on KEVIN's board, may be KEVIN can tell us what they should be. Also need to see if they are installed with correct polarity.

[Tvbob]

Re: Olevia 337-B11 Need some help with this one please!

Thats the first thing I checked, I don't know if the set was working with this repair. Or somebody tried to fix it, before it was sold to me. I am a retired TV repair man I bought it this way because the screen is good. Thanks agian

[kevinm34232]

Re: Olevia 337-B11 Need some help with this one please!

C33 = 100uF 16V
C62 = 470uF 25V
C69 = 22uF 25V

[Tvbob]

Re: Olevia 337-B11 Need some help with this one please!

Thanks kevinm34232, c#33 the 100uf@16v cap gets hot fast. found a shorted SMD zener diode, board # zd2 anybody have a guess as to the zener's voltage?

[budm]

Re: Olevia 337-B11 Need some help with this one please!

Check the polarity of that C33, it is either installed backward or too high of the voltage is feeding it. Since the board was worked on bu some one else, I would real close at all other components and soldering works.

[Tvbob]

Re: Olevia 337-B11 Need some help with this one please!

Thanks budm, Caps do get hot when installed reverse of the polarity. That was what I was hoping for. Not the case here. I did find a shorted SMD zener diode off the negative side of c33.

[Tvbob]

Re: Olevia 337-B11 Need some help with this one please!

Searching around here and the web for similar circuits.

[homedad]

Re: Olevia 337-B11 Need some help with this one please!

I know this is an old thread, but I recently acquired a non-working 337-B11 with similar issues. It would turn on, stay on for about a minute or two and then go into standby.
Looked inside and found 1 swollen cap and one that was leaking - so I replaced all the caps.
Now, I have no picture at all.
I do not any any 12v or 24v from the PS. Standby, blue light, ps_on is working correctly. Main cap is about 160 when off, and about 366 when on.
Following clues from others, the diodes and FETs seem ok.

So, what actually turns on the PS? I had a cap fail by IC1. Could that be damaged? How does one check that part?
I am trying to narrow down the potential parts to see if it is even worth fixing.
Thanks for any help.
John