Well now that i took the caps off for a better look at them I cant shine a light to it. Any idea were to find the inverter at a cheap price?? And how many are their?
The inverter APPEARS to be on the power supply board. There is a serious shortage of decent pictures in this thread. First you have to establish if (and why) it is misbehaving. Then you must decide if it is possible to repair it.
Sounds like an inverter problem. Can you see a picture if you shine a flashlight on the screen?
PlainBill
Well now that i took the caps off for a better look at them I cant shine a light to it. Any idea were to find the inverter at a cheap price?? And how many are their?
Some stuff came up and I had to stash the TV project for a while. I'm getting back into it tomorrow. So I should check the voltage on the rectifier? Exactly what am I looking for? Are most rectifiers of that type in a black box?
If I test some voltages at various places could you guys help me troubleshoot?
Any update on this?? Tv crapped out on me (poliroid tda-03211c) which is why im here, the caps that are mentioned here dont look bulgy. I did notice a red led light in the back blinking before i did anything too it. My two caps are HEC 10uf 450v other side zp105* cv22 ,which i have removed already. I bought the Panasonic ones to replace hopefully thats the problem. Oh forgot to mention i have sound and everything looks like it work but no pic. And like all the combo tv no working dvd either.
Some stuff came up and I had to stash the TV project for a while. I'm getting back into it tomorrow. So I should check the voltage on the rectifier? Exactly what am I looking for? Are most rectifiers of that type in a black box?
If I test some voltages at various places could you guys help me troubleshoot?
The last time I replaced power supply caps that were good quality but buldged I measured the voltage. It was 80v and the caps were 100v. The failure was due to heat.
This is a different type of supply as plainbill said. Most 450v caps are around 100uf that I have replaced on an lcd.
I would check v before I would replace the caps. It is very easy to make a voltage doubler out of rectified a/c. Check your full wave bridge if it has one. I don`t like caps under heat sinks either and transformers get even hotter.
They might have but my neighbor is not an intellectual powerhouse. When I called the shop an old Asian lady answered the phone and wasn't very helpful. I thought she might have said it wasn't a capacitor problem but she could just as easily have said that just because I said there wasn't any visual problems. (Hard to communicate with her) She acted like she was mad that they chose not to fix it and she seemed aggravated with me because I was trying to fix it myself and take away her money or something. Basically, it seemed like she was purposefully not telling me what they thought the problem was.
My guess is that they were going to replace either the power supply, the logic board or both and then charge the remainder for labor. I went to an electronics professor at my school and he said that most of the time that is what is done rather than replacing individual components on these made-in-China devices. Also, he tested the capacitance of the cap I took out (the 150 uF) and it was 137 which he said was close enough.
I am going to replace the two smaller caps and the big one first and then, if that doesn't work, I will replace the rest. If that still doesn't work I will replace the power supply board. I will check voltages tonight.
You must have an ESR meter to easily check the esr. Of course, visual checking caps for leakage and/or round tops are first thing. BUT a bad capacitor doesn't need to look bad. Best thing is to replace the bunch of secondary caps. Wonder why the repair shop quoted it 400, could be some more serious problem than bad caps... Didn't the repair shop give some info about what they wanted 400 for?
Well, due to my ignorance and lack of forethought I have already pulled out the large capacitor and possibly damaged it in so doing due to me having to pull it off the glue it was in with some pliers. Surely it won't hurt to replace it, right?
Is there some way I could test the smaller caps on the "right" side with a multimeter that just measures voltage and resistance?
Also, should I just go ahead and replace the capacitors that I have mentioned or is it probably something else? It couldn't be the fuse, right? Or else the red LED on the front wouldn't be lit?
I would say that the primary cap is often NOT the source of problem. Since it's a 450V cap it's probably a boost-pfc in front of it. (Without pfc 385-400V caps is normally used)
This cap has to be pretty bad to give any trouble.
Check the secondary side capacitors. They generally operate at higher ripple currents and demans higher performance (lower ESR) capacitors. ESR is a pure resistive element inside the capacitor which only gives heat dissipation inside the capacitor. As this heats up the capacitor even more it tends to manifest itself in a destructive manner.
I received a Polaroid TBA-03211C flatscreen TV from my neighbor who was moving out. He said the TV wouldn't turn on and he took it to a local repair shop and they quoted him $400. That obviously wasn't worth it so he gave it to me (because I KNOW I can fix it for much less).
I am not an electronics expert but I am somewhat experienced in general electronics work. Basically, I wouldn't be able to design and/or troubleshoot a device on my own without some instruction but I can hold my own and learn quickly.
The power button on the side of the TV will not turn it on--no picture or sound. The front LED stays red. When the power cord is plugged in I notice a slight clicking/buzzing sound that immediately goes away (something that doesn't seem abnormal to me).
Upon inspection of the power supply I didn't notice any bulging capacitors except for the largest one on the "left" side (Manufact: HEC, 150 uF, 450 V). I took it out and will be replacing it soon. I will also be replacing the two capacitors mentioned in this thread. Do you think this could be the problem? If not, what do you think it is? I do not have a very good multimeter or an oscilloscope but, if need be, I can probably use one at the school I am currently attending.
If there is any other information or images you need from me, just let me know and I will cooperate. Thanks in advance!
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