Daewoo Model DP-42SM won't turn on

[tieny]

Re: Daewoo Model DP-42SM won't turn on

theres no PWR_CTRL labeled on the board as stated in the manual, but tracing the connector back to part of the main board, there is one named "PSM_ON" would that be the one? There are still no voltages on the pins except for STBY5V and LED_P.

STBY5V - 5.09V
GND - 0V
3rd pin - 0V
PSM_ON - 0V
LED_P - 4.75V

I found that when I unplugged the 5 pin connector from the board, the TV won't power on (Red LED goes off).

What specifically are we looking for? What does it mean when theres no voltages on ON/OFF?

[tieny]

Re: Daewoo Model DP-42SM won't turn on

Checking around the components near the 5 pin connector, I found an Oscillating voltage on one end of this resistor and the other end measures 101v. The range of oscillation seems to decreasure over a period of time. Not sure if its relevant?

[tom66]

Re: Daewoo Model DP-42SM won't turn on

The oscillating voltage may be important later.

The lack of PSM on probably means a problem with the main board. Check all the voltage regulators there.

[selldoor]

Re: Daewoo Model DP-42SM won't turn on

Did I understand you to say you had checked 3 fuses?
If so can I assume these are the 3 glass tube fuses?

There are other fuses mentioned in the manual as fusible resistors - did you check them.

Also in Post5 picture five there is a fuse F801 and possibly another at FU801 did you check these.

There may be more but I dont have time to look, tried searching the manual but didnt turn up anything, so over to you. May be some on the backs of the boards as well.

[tieny]

Re: Daewoo Model DP-42SM won't turn on

Ok I think I might of short circuited something. While measuring the component circled in the picture I got readings of

pin1: -49V
pin2: -54.7V
pin3: Reading out of range?

I accidently slipped while changing my multimeter and touched pins 2 and 3 and then there was a small spark =(

Now the red LED power light won't come on.

I checked standby voltages and it is now zero. Checked the fuses and they still seem good, so I'm sure something got fryed.

I rechecked the component that I shorted and got measurements.

pin1: -49V
pin2: -54.7V
pin3: oscillating between 0 to -30 V

I searched up the component below it and it seems to be a power rectifier diode? The picture is in the previous post,the 1st pin of it was also reading out of range, guessing voltage > 600 and the 2nd pin read 54.7V


the power rectifier diode I measured again after the spark
pin1: oscillating between 0 to -30 V
pin2: 54.7v

What was shorted?

[tieny]

Re: Daewoo Model DP-42SM won't turn on

Eh I'm still stuck and don't know what I'm looking for. I thinking I should just buy another psu and just start swapping components.

http://www.ebay.com/itm/DAEWOO-DP-42...item20c31e1c26

[tom66]

Re: Daewoo Model DP-42SM won't turn on

Eh I'm still stuck and don't know what I'm looking for. I thinking I should just buy another psu and just start swapping components.

http://www.ebay.com/itm/DAEWOO-DP-42...item20c31e1c26

It depends on what the TV is worth.

Remember it's 480p. Not even 720p or HD. So it's not worth much. I picked up a nearly working 480p LG Plasma 42" for £2.20. Heck, I have trouble selling 720p plasmas now...

[tieny]

Re: Daewoo Model DP-42SM won't turn on

Well, I'm trying to get a working 42" tv for my room but my last 2 projects became a bust and I'm still stuck on my little 23 "

My question is, what could of cause the tv being stuck on standby and not powering on? Defective regulator, transformer, capacitor before I accidentally short circuited it?

[tom66]

Re: Daewoo Model DP-42SM won't turn on

My question is, what could of cause the tv being stuck on standby and not powering on? Defective regulator, transformer, capacitor before I accidentally short circuited it?

Probably a main board problem.

[tieny]

Re: Daewoo Model DP-42SM won't turn on

Main board problem? What should i check for on the main board? Seems it wont send the signal to bring it out from standby?

[tom66]

Re: Daewoo Model DP-42SM won't turn on

Main board problem? What should i check for on the main board? Seems it wont send the signal to bring it out from standby?

Check the voltage regulators and fuses (if any are present.)

[tieny]

Re: Daewoo Model DP-42SM won't turn on

I'm working on another daewoo model now (Don't know how to find the shorted component from the previous one). This is the same model with the same problem but silghtly different chassis.

Here are photos of the board with with PSM_ON pin connector. Don't seem to see any fuses, but what is a voltage regulator? Can you point it out from the photos shown, Which one is it, and how do I know if its defective?

I just now noticed that if i press the menu buttons or any other buttons, the relay clicks, and the red LED power button turns green but still no picture. Hadn't noticed the buttons that was on the other side under the panel til now.

[tibimakai]

Re: Daewoo Model DP-42SM won't turn on

IC610, IC611, etc.

[tom66]

Re: Daewoo Model DP-42SM won't turn on

Check each pin on each device which looks like the ones tibimakai suggested.

[jeffescortlx]

Re: Daewoo Model DP-42SM won't turn on

The power button is just a Standby/Off switch.

To turn the TV on, with out the remote, you just need to push one of the other buttons, like volume.
There is nothing wrong with your power supply.

This is why you have no video:
https://www.badcaps.net/forum/showth...619#post249619