Discussion in 'General Electronics Discussion' started by bwspot, Nov 25, 2013.

1. ### bwspot

15
0
Nov 25, 2013
One thing i am not sure of is that there are 3 capacitors of value of 25V 1000uF.
1 is taller then others.
It is marked with "w7a pet"
others are marked with "kmg"

can i just get 3 caps of 25V 1000uF?

thx

Last edited by a moderator: Dec 9, 2013
2. ### OLIVE2222

690
25
Oct 2, 2011
On the schematic cold side I see 2X1000µF/25V caps and 2X1000µF/35V caps
You can go for 4X the 35V (assuming they fit on the available room) not the other way around. Look VERY CAREFULLY at the capacitor polarity, when wrongly mounted they can explode !

Olivier

3. ### bwspot

15
0
Nov 25, 2013
if you look at the photo i attached you can see there is a 3rd cap there that is also 1000uF 25V, but is taller.(marked green)

4. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,497
2,839
Jan 21, 2010
The larger one is a 105C rated cap, are the smaller ones 105C, or 85C?

It's possible that the larger cap is a low ESR cap, and all other things being equal, they'll be a little larger.

5. ### bwspot

15
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Nov 25, 2013
they all marked 105(M)
i am just curious what is the difference.
If they mark same on schematic why would 1 be different?
The caps that i am trying to order are low esr:

http://www.mouser.com/Passive-Compo...5Z1z0wrjwZ1z0x1hvZ1z0vn48&Keyword=eeu&FS=True

The taller one is marked cb852 on the schematic.
others are cm853 and cm858

Can i simply go with 3 times 1000uM 25V

Also, if i measure the voltage directly against the board pins of the capacitor would it discharge it if it has an charge?

6. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,497
2,839
Jan 21, 2010
I cannot see the reason why they are different. My thoughts would be to replace them all with the same type.

The ones you have identified seem suitable and are a good brand.

If you measure their voltage they will discharge, but it might take weeks. Get a 100 ohm resistor (or something similar) and place that across the leads for a few seconds if your voltmeter reads more than a volt or so.

7. ### bwspot

15
0
Nov 25, 2013
What kind of resistor should i get.
http://www.mouser.com/Search/Refine.aspx?N=254363

25,497
2,839
Jan 21, 2010

15
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Nov 25, 2013
10. ### bwspot

15
0
Nov 25, 2013
So, i replaced all caps and seems like the caps were good and replacing them did not fix the issue. The tv power led still blinks when i try to turn it on, but it never turns on. I wonder if there is anything else that i could check for, before i throw the tv to the garbage? I am not a tech, so i can do only what i read on line. So anyone has any advices?

thx

11. ### shumifan50

578
57
Jan 16, 2014
I had a Bush TV (rubbish) and it had the same symptoms. I examined all the caps on the power supply, which is what was suggested on several threads on the web, could see none that seem swelled, leaking or damaged in any way. So I proceeded and replaced ALL the caps on the power supply board and that fixed the problem.

12. ### KrisBlueNZSadly passed away in 2015

8,393
1,271
Nov 28, 2011
Did you read the readme.txt file that was included with the PDF of the power supply linked in post #14? It says:

-----
Power supply Samsung BN44-00208A TV model LE32A559(P4F)
Symptom: TV will not turn on, just sometimes, when connected to AC power LED blinks short, after disconnecting the AC power just so. Power inverter (24 volt) is turned on, the lamp off.

Problem: optocoupler PC801S defective - replace. Then replace the RP809, RP810, RP811, RP812, RP816! Good luck! BART
----

It might be worth replacing that optocoupler.

13. ### bwspot

15
0
Nov 25, 2013

thx i missed that