Polaroid flm-373b : No standby light and no power .

[TJVJR]

Hello all , This is my first " official " Thread . I have posted on others concerning this model but I figured it may be better to start one of my own . I bought this TV used about a year ago and at that time it had standby light that would change from red to blue when power button was pushed but would not power on. I did some research and found the capacitors fail causing this problem so I replaced 2 ( circled in pic ) failed/bulged 1000uf 10v caps . It worked good until a few days ago , The lights / electricity went off during a thunderstorm twice and after the second time it would not power on . This time it has no standby light .Everything else ( Surround sound , powered sub , cable box ect .) on that circuit worked as it should so I don't think it was a surge or lightning but I could be wrong . I removed the panel and found 2 failed/bulged caps and replaced them , still no standby light. I have checked every fuse ( 1 at cord , 2 on PS ) and diode(s) and they all are good. I went ahead and replaced most of the remaining caps ( I didn't replace the 2 1000uf 10v caps that caused the first problem and The 2 large ones were not replaced but check good and are holding power ) and checked for 5v at the SB pin , no voltage at all there or at and of the pins . I know I am getting power as far as the second fuse but haven't confirmed it anywhere else , I am not sure where to check . I have tried unplugging outputs referenced in other threads concerning this model and still no standby power .I pushed down on the main board ( again referenced in another thread ) to no avail . The replacement caps are from a local electronics store , I cant remember the brand but I have successfully used them in other power supplies .I did remove a couple caps from a monitor power supply to try and get it going as it is our primary TV . I will try to get better pics , I just had a cell phone to use for pics . I am not sure what to do now and will greatly appreciate any advise / instruction .Thanks all , Ted.

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Not my tag but it is the same as mine can't be seen well in the pic -

[budm]

Re: Polaroid flm-373b : No standby light and no power .

There are two small caps in the stby power supply section, one in front of the MOSFET mounted on the small heat sink, another one is on the right of the heat sink next to the 8 pin SMPS IC for the stby power supply. I would replace them.

[TJVJR]

Re: Polaroid flm-373b : No standby light and no power .

I believe I know the 2 you mean , could you circle them in the pic? Sorry , I am fairly new to this .

[budm]

Re: Polaroid flm-373b : No standby light and no power .

Here:

[TJVJR]

Re: Polaroid flm-373b : No standby light and no power .

Thank you. I had already changed c109 and now I will change the other one. I believe I will go ahead and (re ) change the ones I did a year ago to fix the original problem. What is that just above The circled cap on the left in the picture ? It kinda looks like a cap but isn't .

[TJVJR]

Re: Polaroid flm-373b : No standby light and no power .

Thanks for your help. I had 2 new 1000uf 25v caps and I used them to replace the year old 1000uf 10v caps . I also replaced the other 47uf25w ( from a old power supple ) you told me to and it powered on fully . It takes the indicator light longer than usual to go from red to blue when turning on or blue to red turning off. When I carried it back into the living room and plugged it back up it had a red light and it turned to blue but didn't power on so I removed the back and checked for bulged caps , they all look good. I was going to stop for the night and decided to plug it back up and it came back on but took a while after the indicator turned to blue. Its on now and seems fine but I am afraid to turn it back off. I checked and double checked my work and connections. Should I replace all the caps and if so what brand would be best ?

[budm]

Re: Polaroid flm-373b : No standby light and no power .

I would get good new set of caps, such as PANASONIC FM/FC/FR series from Digikey, I use them for ALL my repair (I use FC long before PANASONIC came out with FM series later on (it has better spec than FC series) in 2003 with great result. They have to be good quality low ESR type made for switching power supply.

[TJVJR]

Re: Polaroid flm-373b : No standby light and no power .

Thanks again , if it gives trouble again I will replace them .Where is the best place to get the caps?

[TJVJR]

Re: Polaroid flm-373b : No standby light and no power .

Been a while but I had replaced the caps and it did well for a while and then it started the same malfunction again , It would not power up when the blue light was on . Strangely enough if I let it cool down and held Ice against the Caps in question ( tried heat as well ) it would power up normally . I just left it on all the time but recently the the power button was accidentally hit and now it has no power light at all. I replaced every cap except the two large ones again and checked everything I could . The board looks slightly damaged near the cap ,it also had been arcing inside the main plug to the power board and I replaced the plug as well.The only thing I would know to do now would be to replace the entire board but any advise would be appreciated .

[CapLeaker]

Re: Polaroid flm-373b : No standby light and no power .

Dunno... if you used "generic" caps and not quality ones first place, it's about time for another set of caps. Other than that if you feel you can get a new board cheaper that it is worth your time and effort to repair you old board, than go that route.

It's always about the voltages...
check if standby voltage is on (it is always on).
unhook everything from the PSU and force it on. See if the PSU fires up and all voltages are present.
use 1k ohm resistor from standby voltage to PSon (or standby what ever it is) and another 1k ohm resistor from standby voltage to BLon (backlight).

[TJVJR]

Re: Polaroid flm-373b : No standby light and no power .

I found a fair priced power supply ( $30 ) but not sure if I should try it. I replaced the caps 3 times but I believe I damaged the board while installing one of the caps . It still does nothing when plugged up but does have power to the one fuse I can find .. While typing this it occurred to me it could be the power button itself but I never had any trouble with it or and other buttons before plus the remote worked fine too. IDK... Just hate to throw it away thinking it may come in handy later , I recently repaired a Vizio I had in storage for my dad when his Funia quit ( still looking in to whats wrong with it) .