An email and a phone call from Eastern Caribbean

Yesterday I received a phone call from a prospective Customer from Eastern Caribbean Mr, A Joseph , He has send me an email one day before but I missed it so I was not able to reply hence the follow up via phone.. And from the short conversation we had I can conclude one thing…The Man has a passion for electronics! Let’s hear his story.

Hi Kimathi, can you please send me the Western Union or Money Gram information for me to order your E book. Once I make the order and the money is sent I will contact you immediately (two weeks max). 

You have no idea how much I have learn from you and I have not even bought the book yet imagine that huh? All my years doing mediocre repairs I was able in an instant to change my approach and I just can't wait to get your book and some from Jestine Young you guys are my greatest Hero's honestly.

My greatest problem is Power supplies no matter how much I research and try everything am just not able to solve them. My latest problem is with a small TCL model ec14276 (though I have a LG, Sharp and a Daewoo open) which the Standby light comes but it will not Power on.

I read your free lesson and I just! appreciate you so much because it really open my eyes about Dead TVs the scenario you spoke about was just a little different (Secondary section seems okay voltage is low 16Vdc on B+ to FBT so I will have to check this area around the PWM IC from the SK2996 which receives 140V but the # 2 pin on the pwm IC pulsates a little so that is why I really need to get your book right?

Thanks my friend I will look forward for the above details so I can begin my career with your help.....Thanks again and God bless. AJ

Hi Humphrey it's me again I spoke to you on the phone here in the Eastern Caribbean. Please send me information for Western Union or Money Gram for purchase of E Book. Thanks so much!!!

Hi Joseph,

Power supply problems are the easiest to solve Joseph, most S.M.P.S power supply has less than 30 components in total and these you can even test them very fast one by one.

This is done though as the last resort because by using voltage testing analysis you can easily pick 90 % of the problems in power supply.

S.M.P.S has both the primary side and secondary side, to understand this better I would recommend you get hold of a DVD power supply and you will get the picture clearer.

Many technicians have no problem with the primary side power supply repair but when it comes to the secondary side is when they get confused.

Let me point out here that most of the time you find a dead power supply the problem is usually on the secondary side.

Did I say secondary side?, YES…this is because the S.M.P.S is designed in such a way that if there is a problem on any of its outputs-Most TVs has 2 to 5 outputs on their power supply ( usually a short on any of these outputs can cause the whole power supply to appear dead) and if a tech don’t have enough knowledge of how the S.M.P.S power supply works may waste a lot of time checking on the primary side while the problem is actually on the secondary side and end up even not repairing the Equipment.

Coming back to your question, I have noted and I quote “Secondary section seems okay voltage is low 16Vdc on B+ to FBT”. This is where the catch is ….16 VDC on the B+ pin of the FBT is not Okay Joseph. I am expecting 90 + (plus) Vdc depending on the size of the TV.  

 So in your case I would advise you to cut off the B+ line just before the B+ FBT pin and substitute it will the dummy load(60 watt Bulb) I have used on my free lesson.

If the Voltage increases and the bulb lights steadily and you are able to measure 90 + vdc, then you can conclude that the power supply is working well and should not be considered for any further testing.

If the Voltage remains low then we can conclude that there is a problem with the power supply especially the feedback circuits.

All the best Joseph

Humphrey