Daewoo LCD 42" model DLP-42C1

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

thank you for the tip

[tom66]

Re: Daewoo LCD 42" model DLP-42C1

You need to use volt DC to test, 20V range is fine.

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

i ll do it tomorrow i have to put back everithing so i can test it again i was thinking wat i did on the pics will help but no probleme better to be shure thank you

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

hi here is the test on the regulators

i try to find out the datasheet here: http://pdf1.alldatasheet.com but it is not that easy

IC507 =AZ1085S
25EI
504BJ
pin 1 =0.00vdc
pin 2 =0.00vdc
pin 3 =0.40vdc

IC508 =1084_33
064OBL
pin 1 =0.00vdc
pin 2 =0.03vdc (free to air)
pin 3 =0.40vdc

IC711 =EH16A
637J06
pin 1 =0.00 vdc
pin 2 =3.29vdc
pin 3 =5.09vdc

there is only these 3 regulators on that board
if you want me to test some other part just tell thank you

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

hello tom,selldoor and all out there

i did some other test on th main board and the psu:

on the main board:

P803A
Pin 3 =0.32vdc
nothing on the other

PA912
Pin 1=3.29vdc
Pin 6=3.26vdc
nothing on the other ones

PA911
Pin 1=3.29
Pin 4=3.29

for the psu
it is very strange
I have removed the psu circuit boards from television and tested with power on
it is very strange I have power everywhere but very low 71VAC on the hot side and the cold side throughout 12.9VDC all this on the back of the board
also inCN2, CN3, CN4, CN5, CN6 of all, I have 12.8 or 12.9dcv.Where i just found 1 or 2 pins in differents CN
When I measured and circuit boards were mounted on the TV I had 114VAC at the bottom is hot side except I had 98VAC IC2 and IC3 around 20Vdc and allmost nothing

CN3
Pin 5=4.9vdc

CN4

Nothing on all pins

CN5

Nothing on all pins

CN6

Nothing on all pins

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

Good evening after a long stop now it is time to go on this tv again

i did some change on my psu :2 new bridge rectifier BD1 and BD2 + a new IC1

the old one was blown but keept somehow together wen i desoler it it went in 2

parts then Q1 and Q5 are changed too and some resistors

Now after reading a lot here tom66 and many other how to test a psu so i did

a jumper on CN3 5VS and P/O and did some test :

CN3
12V pin 1 i find 7.60DCV
12V pin 2 i find 7.60DCV
GNDpin 3
GNDpin 4
5VS pin 5 i find 5.12DCV stady
P/O pin 6 attached to pin 5 =5.12DCV
GND pin 7
NC pin 8

on CN2
30V pin 1 i find 19.17VDC
30V pin 2 i find 19:17VDC
GND pin 3
GND pin 4


CN5 and CN6
B/O Pin 1 i find 0.01 VDC
Dim Pin 2 0.01 VDC
GND Pin 3
GND Pin 4
GND Pin 5
GND Pin 6
GND Pin 7
24 v Pin 8 i find 15.58DCV
24 v Pin 9 i find 15.58DCV
24 v Pin 10 i find 15.58DCV
24 v Pin 11 i find 15.58DCV
24 v Pin 12 i find 15.58

CN4
Dim Pin 1
B/O Pin 2
NC Pin 3
GND pin 4
GND Pin 5
NC Pin 6 i get 7.56DCV
12V Pin 7 i get 7.56DCV

the relay is klicking att start by plugg in the power all the other boards are

not connected during this test so now i wonder if i can reconnect the other

boards and keep the jump on the CN 3 and test it or wat to do?

any help will be great thank you

[tom66]

Re: Daewoo LCD 42" model DLP-42C1

All the voltages are low.

Please can you test your meter - measure a fresh 1.5V AA battery - see if it measures nearly 1.5V.

[selldoor]

Re: Daewoo LCD 42" model DLP-42C1

Hi - I was hoping you would get a better camera for christmas and retake the pictures.

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

Hi tom,selldoor

The dmm is quite ok i did test a new battery and it is ok
i think is something on the psu ho is not corect yet maybe the big capacitor that i replaced
the old one :180uF450v and the new one have 220uF450v i d´ont know if it can affect
or maybe because i use a pc jumper with out a transistor to short the 5vs and P/O pins
as you can se on the attached pics

selldoor yes i have a camera now lol here some pics
thank you

[selldoor]

Re: Daewoo LCD 42" model DLP-42C1

Hmm not sure about the photos - perhaps try again in daylight near a window if it ever gets light in Sweden.
The flash makes every joint look suspect!
If you can get it, one decent well lit picture of the whole board is better to follow.
Resistors R14 and R55 dont look soldered back on the left side?


Re you measuring VAC are you sure your meter was set on AC
not DC and what did you use for ground? On the primary side it is usual to use the negative leg of the Big cap ,not the chassis or ground screw.

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

Hi you mean the early measuring in the first page yes it was on ac but i did it with Steinel Digi Check3 this meter alternate automaticly from AC to DC depending on wat he find
and AC was the resolt
but the lasts measuring i did it with DMM BS1901W and all was DCV measuring
i´ll try to do better pics as soon as possible
thaank you

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

Hi again selldoor here some pics i hope they are better you did not say anything about the big cap i assume it is ok then or do i have to put back the 180uF 450v
thank you

[selldoor]

Re: Daewoo LCD 42" model DLP-42C1

No I meant this:
for the psu
it is very strange
I have removed the psu circuit boards from television and tested with power on
it is very strange I have power everywhere but very low 71VAC on the hot side and the cold side throughout 12.9VDC all this on the back of the board
also inCN2, CN3, CN4, CN5, CN6 of all, I have 12.8 or 12.9dcv.Where i just found 1 or 2 pins in differents CN
When I measured and circuit boards were mounted on the TV I had 114VAC at the bottom is hot side except I had 98VAC IC2 and IC3 around 20Vdc and allmost nothing

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

yes exactly it was 71VAC on the table and i had 114 when mounted and all the other measuring .is the pics ok this time?
i beleave now the situation changed because as i did change the BD1 and BD2 plus Q1 and Q5 and R14,R55 and yes they are soldered but i will resoldered

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

Good evening

please i need your help to go on this project

thank you

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

hey Tom and Selldoor and everyone else here,please I need your support.

I have done a few things on this PSU until now.

New on the board= Q1, Q5, BD1 and BD2 plus I changed R14, R54 and R8

and some diodes D21, D23 .

performed some measurements:

from the minus of the C23 :

to IC1 pin 8 i have 10.7DCV

to D21 = C23 to 10.9DCV

to IC2 Pin 12 = 00.0DCV

to D8 = 9.7DCV

Now from the minus of the C32 :

to: 5vS = 5.5VDC

to P / O = 5.5VDC

Pins 12V = 7.4Vdc

to CN5 and CN6 :

from the minus of the C32 to Pins 24V = 15.5Vdc

the C4
from the minus of the C32 to Pins 12V = 7.5VDC

To CN2
from the minus of the C32 to Pins 30V = 19.1Vdc

I still do not have them 12, 24 and 30V needed.

what and where shall i look next?

thanks in advance

[tom66]

Re: Daewoo LCD 42" model DLP-42C1

So, I am a little lost, bring me up to speed: Do you have any DC output voltages from the PSU yet, aside from the 5V STBY?

[selldoor]

Re: Daewoo LCD 42" model DLP-42C1

Yes, lost me as well, not that it takes much!!. When we cant see the boardsor what you are doing sundry measurements dont mean a lot, so we have a more boring approach. I looked at this yesterday and thought we are going to have to start over again - the 71vAC threw me completely.

So, with a source connected Tell us again what happens from when you plug in, then switch on to the stable fault state. What doies the power light do, what does the screen do, any noises clicks etc - any sound?

Then when it is plugged in but not switched on what is the voltage on the Big Cap ( CARE HIGH VOLTAGE) then what is the voltage after you have pressed the power button.


I see now the sockets are all labelled so make another list as you did before and measure all the voltages on all the pins (meter on 200vDC black probe on a ground screw)
Do this with everything connected, if you can.

Retest the voltage regulators on the main board and post the results as you did before with the board number, part number and 3 voltages.

[bohaboha]

Re: Daewoo LCD 42" model DLP-42C1

Hi sorry i d´int specifie that all the measuring done on post36 was on the board out out of

the tv and with jump on 5VS and P/O. On the C23 the big cap i have 326d ,ok i will put

back everything in place and be back to you soon thank you

[tom66]

Re: Daewoo LCD 42" model DLP-42C1

There should be around 390V across that cap if the PSU is working, 325~340V or so in standby.