Polaroid FLM-373B Power LED but no picture, already tried replacing caps

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

On what, the "35419" of the part number? I just double checked and it is definitely a 35 there.

Yeah, strange 3.5V regulator... not a common output voltage.

Since you're in the USA: http://search.digikey.com/us/en/prod...ICT-ND/1301474

is a good close replacement. 3.3V is close enough to 3.5V to most chips that it should not matter.

This is also a part for part replacement, so the pins should match.

plus about $3 shipping.

[pattheslat]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Thanks for all your help. I will try that part and see what happens.

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

I'm just a little baffled now about what voltage that regulator is supposed to output.

It's definitely askew as 1.95V is no where near a standard voltage and most of these regulators seem to drop to around 2V when they fail.

The "35" in the part code seems to indicate 3.5V, as the "25" is in the other part code does match the 2.506V output.

Strange... Very strange. Does the regulator have any logo on it?

[pattheslat]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Nope, absolutely nothing on it besides the numbers.

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

I'm looking at the two resistors and thinking adjustable regulator but it still doesn't look right. Have you ordered the part yet? If not, hold off for a day or two for someone else to put their input in.

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

I'm reading the two resistors as 110 ohms and 61.9 ohms each. I put these into a calculator and get 2V output, which matches the measurement.

So I'm not so sure if it is the regulator at fault. Can you double check pin #1 relative to the metal case of the TV, and then measure the voltage from pin #1 to the tab?

[pattheslat]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Sorry to not respond for a week, I moved to a new state and started a new job, so I haven't had any spare time.

Now when I check the voltages, I'm getting .704 from pin 1 to the case, and -1.243 from pin 1 to the tab.

[Scenic]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

that 1084 is a voltage regulator.. used as an adjustable version (2 resistors on the GND/ADJ pin)
I just came across an AMS1084CT in TO-220 a week or so ago and looked it up. That's why I remember this.

Searched for 1084PE and alldatasheet threw an APE1084P at me, which is available in TO-252 like yours.
http://www.alldatasheet.com/datashee...PE1084P15.html

[pattheslat]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

that 1084 is a voltage regulator.. used as an adjustable version (2 resistors on the GND/ADJ pin)
I just came across an AMS1084CT in TO-220 a week or so ago and looked it up. That's why I remember this.

Searched for 1084PE and alldatasheet threw an APE1084P at me, which is available in TO-252 like yours.
http://www.alldatasheet.com/datashee...PE1084P15.html

I'm having a heck of a time actually finding one for sale anywhere, googling just brings up data sheets. Any idea where I could find one?

[PlainBill]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

I'm having a heck of a time actually finding one for sale anywhere, googling just brings up data sheets. Any idea where I could find one?

This is a 'jelly bean' part - available from a number of different manufacturers. The 1084 is the 'core' identifier. Any suffix identifies the output voltage and package. Each manufacturer uses a unique two or three letter prefix. Digi-Key has them in the AP (Diodes Inc) and LT (Linear Technology) prefixes.

There seems to have been a little confusion with what you are looking for, U13 is a 2.5 volt fixed output regulator, U33 is an adjustable output regulator, and as tom66 indicated, is PROBABLY bad.

Digi-Key AP1084DG-13DICT-ND at $1.48 is a replacement in the TO-252 package, AP1084KLDICT-ND is $1.63 in the TO-263 package; either compare datasheets or trust tom66.

PlainBill

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Sorry to not respond for a week, I moved to a new state and started a new job, so I haven't had any spare time.

Now when I check the voltages, I'm getting .704 from pin 1 to the case, and -1.243 from pin 1 to the tab.

Hmm, my error. 1.243V is a good reading for this regulator (should be around 1.25V.) I guess we need to look elsewhere. Are there any regulators on the bottom of the board?

[pattheslat]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Hmm, my error. 1.243V is a good reading for this regulator (should be around 1.25V.) I guess we need to look elsewhere. Are there any regulators on the bottom of the board?

Finally got a chance today to pull that board out, there are no regulators on the bottom of it. So you're saying that regulator is ok?

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Finally got a chance today to pull that board out, there are no regulators on the bottom of it. So you're saying that regulator is ok?

Yes, it looks like it is. I'm kinda stumped right now. I'm not sure why it is not working. Have you got a 2.2k - 4.7k resistor? Maybe the PSU is at fault and that will allow a test.

[pattheslat]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Yes, it looks like it is. I'm kinda stumped right now. I'm not sure why it is not working. Have you got a 2.2k - 4.7k resistor? Maybe the PSU is at fault and that will allow a test.

I can get one. What test can be done with that?

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Check if the supply is turning on and then turning off. We can force it on by pulling PSON high or low.

Recently, I have dealt with an LG power supply which had bad caps. But even after replacing them all it continued to turn itself off. I later found it was the AC detect that was turning it off. Now I'm far more vigilant in testing this, as well as PSON.

[pattheslat]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Ok, I got some 3.3k resistors. Now what?

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Sorry didn't see your post...

I'm very busy now, will reply later after my exams.

[retiredcaps]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Ok, I got some 3.3k resistors. Now what?

Probably something like posts #70 to #80 in a different thread, but same concept.

https://www.badcaps.net/forum/showth...t=18382&page=4

[tom66]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

What Retiredcaps said.

If you post a closer up image of the connector going from power supply to main board we could deduce which pin needs to be pulled up (if it is labelled.) If it's not labelled (#*@$ Proview/Megmeet), then we may have to do some guesswork based on the power supply layout or the voltages at the pins.

[selldoor]

Re: Polaroid FLM-373B Power LED but no picture, already tried replacing caps

Hi I Think I have found the Power Supply Details.It has the pinouts.
I will try and upload it. To read the PDF you may need to download the adobe chinese character reader. http://www.adobe.com/support/downloa...jsp?ftpID=4883
Without it, it just shows as a blank page doesnt even show the english