polaroid flm-373b lcd power issue and fixed!

[cadillacman]

Hey guys finally got a little money to buy a couple tvs...

My latest patient is this polaroid 37" lcd. Model number flm - 373b

When plugged in the red light would come on and shut off or stay on depending on how it felt. When attempting to power up led would turn blue, then dim signifigantly a few times, then stay on blue. No picture, no response, will not turn off with remote or power button.

The former owners symptoms were intermittent lockup wont power off also no remote response, intermittent powerdown, power on several times to get the set to boot, all got worse as time went on untill finally it would not power on anymore. All the symptoms i was hoping to hear...

I had my doubts but tore it down. Found two 1000uf/10v capxon caps.

I did not have any 1000 ufs so i subbed two 1200uf/10v caps. Plugged everything back in and viola! good as new!

I will update if this set fails my overnight burn in test but so far it seems this was a simple repair. An ideal repair would involve replacing all power supply caps just not these two, but in my case im hoping this will get me by.

[Tvbob]

Re: polaroid flm-373b lcd power issue and fixed!

good job, couple of extra (uf) won't hurt.
the earlier lcd's are always fun to work on.

[cadillacman]

Re: polaroid flm-373b lcd power issue and fixed!

to be honest yes the newer ones are easier to work on but like my pseronasl tv is a odl vizio.. heavy lots ot metal inside, solid. Not a cheap plastic turd like alot of these new ones..

Yeah its good ran all night and still running now no probs. I have seen this ps before but i cannot remember where...

[Dgtech]

Re: polaroid flm-373b lcd power issue and fixed!

I just bought one of these sets today for $50 - same problem, same fix. Listing on CL for $250

[cadillacman]

Re: polaroid flm-373b lcd power issue and fixed!

sweet! ( i got 300 out of mine)

[delaware74b]

Re: polaroid flm-373b lcd power issue and fixed!

FYI - did you look under those huge heatsinks on the power supply board? I've found caps UNDER those heatsinks on other MLT-built boards (I found them in an Akai TV).

[Dgtech]

Re: polaroid flm-373b lcd power issue and fixed!

There are caps under there but they checked out ok. The TV is hooked up right now an my wife is watching it so...I'm good with that. If I still lived in Baltimore, I would be able to get $300 for it. Here in Pittsburgh, you have to motivate buyers.

[cbogg]

Re: polaroid flm-373b lcd power issue and fixed!

Must be nice, here in upstate ny the only thing I've run across are 50" plasmas with undetermined sustain board issues that people are trying to get 300 for and just in the last two days a 32" lcd for 150 & a 42" for "only" 200. Both "work great just need to replace screen". Last one was 3 years old and had the gem "this it's why I'm selling it so cheap". Also almost impossible to find non working lcd monitors, those must be ending up in the trash which is now illegal here.

[cadillacman]

Re: polaroid flm-373b lcd power issue and fixed!

picked up another one today. WIsh me luck. THis one las a led that turns blue when power button pressed but thats it no picture.

[cadillacman]

Re: polaroid flm-373b lcd power issue and fixed!

everybody around here is lighting off fireworks( even though its illegal in illinois he he)

here i am tinkering with tvs.

Same two 1000uf/10v caps were bulged. Replaced them and it powers right up now nice display too! The cfls seem to have a ton of life left(nice bright whites)

WHOOHOO!!!!!!

[cadillacman]

Re: polaroid flm-373b lcd power issue and fixed!

set 2 still going strong. I love these sets...

[TJVJR]

Re: polaroid flm-373b lcd power issue and fixed!

Hello all , I am a new member and novice at best when it comes to this type of repair .I posted here because I am having a Issue with this same model . About a year ago I replaced The same 2 caps mentioned and everything worked well until a couple days ago . The power/lights/electricity went off came back on within a few seconds and the set powered back on and worked as usual. About 5 minuets later the power/lights ( thunderstorm ) dimmed for 3 or 4 seconds then stayed off a hour or so .When the power/ lights came back on I could not get the set to do anything , no led light at all . I rechecked the power supply and found the 2 caps I had replaced looked good but I had to replace the larger cap just above those 2 and a smaller one under the heats[/URL][/IMG]
I suspect a bad diode but The 2 I checked ( with meter ) seemed good. Am I missing a diode ? The fuse is good , The main one at the power cord , Is there another fuse I missed ? I have been searching and will continue but any advice will be appreciated.

[johnboy1313]

Re: polaroid flm-373b lcd power issue and fixed!

Could be the main board as well.

[Dgtech]

Re: polaroid flm-373b lcd power issue and fixed!

There may be another fuse on that board. Pic is too small to tell.

[TJVJR]

Re: polaroid flm-373b lcd power issue and fixed!

I couldn't find another fuse and the 3 diodes I found are good. Are there more than 3 diodes ? Everything is checking good but I have no dc output at all . Ac coming in but nothing at the +5VSB. Thanks all , Ted. I appreciate any help .

[budm]

Re: polaroid flm-373b lcd power issue and fixed!

Since the 5v power supply is not working, I would verify that you do have 160~170Vdc on the large filter cap, then there is a small start up cap next the small transformer with MLT070A sticker on top. I would replace or heat it up with hair dryer then power it to see if the 5v stby will start up. There should be a smd IC for driving the MOSFET that drive the 5V STBY transformer, you may have problem with the IC or the MOSFET, the resistor on the Souce pin of that MOSFET may have blown open due to shorted MOSFET.
There are snubber didoes in that section also.
http://s807.photobucket.com/user/bud...ml?sort=3&o=32

[TJVJR]

Re: polaroid flm-373b lcd power issue and fixed!

I will try to get pics of the caps I have replaced tomorrow. For reference I will circle them in copy of above pic. What are snubber didoes and do they look the same as regular diodes ?

I also notice a small ark when plugging in the ac cord to the wall , back of tv or the board. Not big but you can hear it pop.

[TJVJR]

Re: polaroid flm-373b lcd power issue and fixed!

C109 correct? I will replace it. I have checked every diode I can find , including the ones under the heat sink.I replaced the caps under the heat sinks as well .

[8ballspecial]

Re: polaroid flm-373b lcd power issue and fixed!

Hello all, just picked one of these up, but it has 1000uf 25v caps. It was manufactured in September 2007. I have found initials where someone worked on it in 2008. Is it possible they put in the wrong caps? 25v instead of 10v?

[budm]

Re: polaroid flm-373b lcd power issue and fixed!

Higher Voltage is find, the main key is that it has to be low ESR type with 105c not generic type and 85c rating, the 25V will have bigger body so it may not fit the footprint on the board.