Funai LF320FX4F Power Supply Issue?

[ZnsaneRyder]

Re: Funai LF320FX4F Power Supply Issue?

I am fixing this same TV with the same issue.

Originally no backlight, and just the Funai logo come on for split second.

I replaced the 2X 47uf caps with 1 47uf/160V and 1 150uf/100V in parallel, and the backlight and Funai logo will come on for a split second, then the set shuts off. The 12.5mm caps will fit if you bend the legs over a bit first.

Also tried adding a 470uf cap, only difference is it flickered on twice, but still shut off. Also tried different mosfet and diode on the boost circuit, same issue.

So upgrading caps only allowed it to come on, but not fix issue.

[ron350]

Re: Funai LF320FX4F Power Supply Issue?

That is why I am asking what would be a good quality replacement of a higher value in a 10 mm x 25mm can.
The original C1006, C1007 caps on my board are Su'scon SL 47uF x 100v 85*.

[budm]

Re: Funai LF320FX4F Power Supply Issue?

So is the original cap is 47uF 100V? but in post 50 he put in 470uF 100V, that will be much bigger cap! something is not right.

[ron350]

Re: Funai LF320FX4F Power Supply Issue?

Hi Budm the tallest cap on my boards are around 12mm.

I soldered a 12.5 x 25 in place of C1006 and put modeling clay on top and there is about 4mm vertical clearance under the plastic back cover.
The problem is there is not enough side room for two 12.5 mm caps so I guess that limits the size to 10mm x 25mm.

[budm]

Re: Funai LF320FX4F Power Supply Issue?

What is the height of tallest cap on that board?

[ron350]

Re: Funai LF320FX4F Power Supply Issue?

OK C1006, C1007 are 47uF x 100v by 10mm x 12mm with 5mm lead spacing.

I think the largest caps that will fit are 12.5mm x 25mm with 5mm lead spacing.

What would be the best caps to use that will fit vertically?

[fixerupper75]

Re: Funai LF320FX4F Power Supply Issue?

Already done!!!!
Maybe this will help next person with their Black Friday special!!!!

[budm]

Re: Funai LF320FX4F Power Supply Issue?

Since C1007 (same value cap) is in parallel with C1006, you might as well replace both of them at the same time with good quality low ESR type.

[fixerupper75]

Re: Funai LF320FX4F Power Supply Issue?

No i didn't but i did notice the voltage dropped to 10vdc with the 47uf 100v cap and with the 470uf 100v it dropped to 50vdc.

[budm]

Re: Funai LF320FX4F Power Supply Issue?

Had the same issue with flashing of the name for 2 seconds. I replaced the c1006 with 470uf 100v and the tv is now working. Does anyone no why this is?

C1006, C1007 are connected in parallel, they are the filter caps for the boost converter to produce the drive Voltage for the LED string.
Did you measure the capacitance and the ESR of that cap.

Pictures provided by shopjimmy.

[fixerupper75]

Re: Funai LF320FX4F Power Supply Issue?

Had the same issue with flashing of the name for 2 seconds. I replaced the c1006 with 470uf 100v and the tv is now working. Does anyone no why this is?

[artstv1]

Re: Funai LF320FX4F Power Supply Issue?

This funai model has a problem with bad L E D,s . remove the front excushion and replace or jump bad one. it is not hard just time consuming. common prob.

[jimmyk]

Re: Funai LF320FX4F Power Supply Issue?

did you ever find a solution ? I have two of these with the same symptoms. Squeal , no led nothing but the squeal.Disconnect from main and the squeal stops.

[genewood]

Re: Funai LF320FX4F Power Supply Issue?

I have had several of these with the same problem. Shuts off after the splash screen. Could be Magnavox,Emerson or others made by Funai. Don't know what the exact cause is but they are easily fixed by increasing the value of C1006.
You need about 470uf /100 volts to be on the safe side.Due to size I usually don't try to mount it on the board just have some wires from under the board.
Plenty of room adjacent to the board.

[chazzmcc3]

Re: Funai LF320FX4F Power Supply Issue?

I have a lf320fx4f also but mine makes a high pitch whinning noise when I plug it in and nothing happens when I push the power button. what would make that noise?

I am having the exact same issue. Did it end up being the main board or the power supply?

[Capacitor_King]

Re: Funai LF320FX4F Power Supply Issue?

Hi,
I was given one of these Funai LF32FX4F TV's
I replaced most of the capacitors on the board (Except for the main big one and the two really small ones) and the set still has the same problem.
It powers on just long enough to see the Funai logo and then shuts down.

I did not test voltages but I did unplug the LED strip and it still does the same thing (I pointed a bright flashlight at the screen, and I was able to see the Funai logo just before the unit shut down)

What else can the problem be?

PS: I am a new member to the forum and also new to board level electronics repair, I only decided to try and repair this power supply board because buying a $54 board for a $100 TV does not make sense to me

[slymaster]

Re: Funai LF320FX4F Power Supply Issue?

If u replaced both boards and still the same problem.then most likely its the LED backlights at fault.

[toxicmonkeylove]

Re: Funai LF320FX4F Power Supply Issue?

hello I have the same problem only mine is a magnavox 32me303v/f7 which is the same just branded as magnavox. when powered on the stand-by led blinks 20X at the 12th blink it flashes the word magnavox on the screen. The 21v p on signal when the set is turned on is 21v after the led stops blinking(and stay's lit) the voltage goes to 11v . the amp 13v signal goes from 13v down to 6.5v. The all 3.3v signal stay's at the voltage 3.3v. this is how far i have gone with it. replace both boards still the same problem

[slymaster]

Re: Funai LF320FX4F Power Supply Issue?

Sorry I dont have the tv anymore-it was a customers that I repaired. I should have measured the voltage from the cathode side as well.However ,from memory I can recall the voltage did jump up to about 45 volts give or take a little when I turned the TV off.I coulld send a pic of the bad LED strip(dont know what good that will do)Which is in my opinion the main problem with this model

[budm]

Re: Funai LF320FX4F Power Supply Issue?

Can I see the pictures of the board?
More likely that if you monitor the Voltage at the Anode and the chassis GND, you may see the Voltage spikes up (the boost converter circuit kicks in) and then settle down to 21V due to the protection circuits kicks in.