Voltage level on LCD power supply board.

[Graffy]

Re: Voltage level on LCD power supply board.

Sorry, I did not see the n.
22 nano Fard, J = 5% tolerance, 2KV.

http://wiki.xtronics.com/index.php/Capacitor_Codes

J is code for +/-5%

B +/- 0.10pF
C +/- 0.25pF
D +/- 0.5pF
E +/- 0.5%
F +/- 1%
G +/- 2%
H +/- 3%
J +/- 5%
K +/- 10%
M +/- 20%
N +/- 30%
P +100% ,-0%
Z +80%, -20%

Thanks guys! I appreciate it.

[mpkozar]

Re: Voltage level on LCD power supply board.

Hello,

I've been reading this thread to repair a Dynex DX-L40-10A tv. Had the same power supply problems described, ordered new caps from Mouser and replaced all the electrolytic caps and the film cap on the board. Put it back together and it powered right up. Unplugged it to move it to a cable outlet and back to the red LED and no picture. After opening up and testing the voltages on the main board I'm getting the following:

Main - DC Volts
+5V - 5.27
+5V - 5.27
GND - 0
GND - 0
BL ON/OFF - 0.05
DIMM - 4.06
GND - 0
+12V - 11.81
+12V - 11.81
+5VSB - 4.96
+5VSB - 4.96
ON/OFF - 2.87
GND - 0
GND - 0

I'm guessing its the main board not sending the signal to turn on the backlight. Anyone have any luck with repairing the main board?

Thanks,

mk

[budm]

Re: Voltage level on LCD power supply board.

You are correct, I myself never have any luck fixing the Dynex/insignia main board. Typical part to check will be the voltage regulators, check the the caps, look for burnt or damaged parts.

[selldoor]

Re: Voltage level on LCD power supply board.

Budm - Is this a totally daft idea? - perhaps for a set for own use only.
What if you cut the connection to the blon pin and connect permanently to either the
dim or the 5v (with or without a resistor.) Might it then work.

[mpkozar]

Re: Voltage level on LCD power supply board.

Measured the voltages on the regulators.

N1
pin 1 - 2.09
pin 2 - 3.33
pin 3 - 5.26

N7
pin 1 - 1.37
pin 2 - 2.63 - stub
pin 3 - 5.25

N10
pin 1 - 9.38
pin 2 - 0 - stub
pin 3 - 5.03

N5
pin 1 - 2.09
pin 2 - 3.34
pin 3 - 4.96

N3
pin 1 - 2.11
pin 2 - 3.37
pin 3 - 5.25

N6
pin 1 - 0.71
pin 2 - 1.42 - should be 2.6
pin 3 - 5.25

N8
pin 1 - 0
pin 2 - 0.42 - should be 1.25
pin 3 - 1.42

I don't see N9 on the board, it must be under the metal cage.

Looks like N6 and N8 are not reading the correct output voltage. Any suggestions on repairing? Should I try replacing the capacitors associated with these regulators as well as the regulators? Some I can replace, others are so small I don't think I would be successful.

I'be been looking for a main board on eBay but not much luck. There's a repair service but they don't guarantee that they can fix it.

Thanks in advance,

mk

[budm]

Re: Voltage level on LCD power supply board.

I would replace the N6. N8 gets it input voltage from N6 output which is too low for the N8 to work, so you need to replace N6 first. I would order 5~6 of these regulators since one is already bad, other may fail sooner or later.

[mpkozar]

Re: Voltage level on LCD power supply board.

Thanks BUDM. I'll give it a try and report back.

[mpkozar]

Re: Voltage level on LCD power supply board.

Success! I replaced N6 and put the board back in and if fired right up! Now lets see how long it lasts.

Thanks for your help budm.

[budm]

Re: Voltage level on LCD power supply board.

Thanks for the repair feedback.

[zukdj]

Re: Voltage level on LCD power supply board.

Thanks to previous posters, this thread is a great help. Question, does 22 nJ mean 22 Nanofarads? (the "J" is confusing me)

My Dynex TV with the same symptoms, (Red Light On but TV won't power up).

Just want to make sure I am ordering the correct value capacitor.

Mine says: (this is cap # c842)

CBB81
2000v
22nJ

I am having the same problem with my Dynex DX-L40-10A, I just cannot find this capacitor anywhere, does anyone have a link to this part? I just thought it would be easier to solder a $2 cap in place instead of spending a bunch of money but I am thinking now it might be easier to just purchase another power supply at this point. Has this been the root of the problem in most instances? I would hate to buy a new power supply and have it not be the problem but I have no testing tools or way to test the power supply as I am a newbie. I get the relay click, blue to red standby light scenario everyone else speaks of.

[budm]

Re: Voltage level on LCD power supply board.

This thread is getting long, so what the exact problem do you have? Post the pictures of YOUR board will help, you also need to get at least a meter to make some measurement.

[sinful_speed]

Re: Voltage level on LCD power supply board.

Hi there. I finally got the power supply installed, the TV turns on and all inputs work well except for the TV tuner. There were no issues with the tuner before the new power supply.

I noticed that the jumpers in this pic were set differently than the new one. Is there any chance that this could be the issue with the tuner?

http://i741.photobucket.com/albums/x...ps7a1d0ffe.jpg

[newuser65]

Re: Voltage level on LCD power supply board.

does any one know of a way to get a schematic for the power supply pcb it seems like im so close

I think this is what you want...
http://www.eserviceinfo.com/download....820.1673.html

[ELETROLISS]

Re: Voltage level on LCD power supply board.

Hi a good day to you al. I am having some issues with a power supply and would surely appreciate some help. This is a DPS-286AP IT HAS NO 5 volts standby. R7914 was replaced. D7908 was replaced. I have 175volts across The diode. Can anyone assist me with The troubleshooting.??