Samsung LE32B530P7N....BN44-00234A

[Andyd1970]

Hi Guys,

Help!

I have the above set in for repair, it takes ages to come on, red light flashes and sometimes it just flashes etc. I thought it was cap related so I changed the main caps and it still does the same, so I started to heat the PCB with a hairdryer and it comes on straight away, so I started to try to locate which part of the PCB was being effected by the heat, I used a piece of paper in like a funnel shape to direct the heat. I have attached a picture of the area that seems to be causing the issue.

I replaced three of the small caps thinking it was them but it still does not come on straight away unless I use heat. I thought I was doing well as my knowledge has come on loads since I joined the site and repaired around 10 TV's for friends but do not want to be beaten by this one.

Am I right in that as it is effected by heat it has to be cap related?

Thank you in advance.

[badwily]

Re: Samsung LE32B530P7N....BN44-00234A

If you have low voltage on 12v , like 8v or so. change the transistor (QB802) D526 TOSHIBA/FAIRCHILD TO-220 Transistor.

Hi Guys,

Help!

I have the above set in for repair, it takes ages to come on, red light flashes and sometimes it just flashes etc. I thought it was cap related so I changed the main caps and it still does the same, so I started to heat the PCB with a hairdryer and it comes on straight away, so I started to try to locate which part of the PCB was being effected by the heat, I used a piece of paper in like a funnel shape to direct the heat. I have attached a picture of the area that seems to be causing the issue.

I replaced three of the small caps thinking it was them but it still does not come on straight away unless I use heat. I thought I was doing well as my knowledge has come on loads since I joined the site and repaired around 10 TV's for friends but do not want to be beaten by this one.

Am I right in that as it is effected by heat it has to be cap related?

Thank you in advance.

[dskall]

Re: Samsung LE32B530P7N....BN44-00234A

Check all solder joints in the area.

[R_J]

Re: Samsung LE32B530P7N....BN44-00234A

Hi Guys,
I replaced three of the small caps thinking it was them but it still does not come on straight away unless I use heat.

I see 4 small electrolytic capacitors in that circuit, which 3 did you replace and why not the forth one?
QB802 is a regulator/switch that supplies the vcc voltage to the pfc circuit, If the transistor is weak it can cause low vcc voltage to the pfc ic.

[nomoresonys]

Re: Samsung LE32B530P7N....BN44-00234A

lol, did nobody see that this thread was made over 7 years ago?

[R_J]

Re: Samsung LE32B530P7N....BN44-00234A

Nope. missed that, need to pay more attention, too bad threads this old were not closed after a period of time.

[dskall]

Re: Samsung LE32B530P7N....BN44-00234A

Doh!
Well, Wisdom is timeless.

[nomoresonys]

Re: Samsung LE32B530P7N....BN44-00234A

Well I wonder why andy didn't follow up with this, too busy huh andy?

[nomoresonys]

Re: Samsung LE32B530P7N....BN44-00234A

similar problem, heating that area brought the backlights on, switched out every cap in that area, still no boosted pfc, all voltages on connector, stby, 12 vols etc, are right on and steady.