samsung le32s86bd main board or psu fault?

[charlierfc]

Hi everybody hope you are all well.

ok, i have a samsung le32s86bdx/xeu here,(not the model i stated on the title! i missed a bit)
When i first turned on the set it powered as i should, the picture was fine backlight fine ect, then after about 30 sec the picture started to brake up, the back light started flickering untill the backlight went out.
Now when i power on the set i get the sound from the speakers for a bit but no backlight.The tv cycles from standby to on with no backlight to off and again continuous.

After opening the set i see no bad caps(looks like they have been previously tested as the tops are marked with a pen!)

iv checked the outputs from psu, they seem fine,well maybe a bit high as the power to inverter is 27.7 not the 24 stated.

Im wondering, would this mean the main board is at fault? or is the higher reading from the psu causing the fault?
Any ideas?
thanks in advance, Charlie.

[anotherdude]

Re: samsung le32s86bd main board or psu fault?

try giving the main board some heat with a hair dryer near the shielded area

sounds similar to what i've had previously

or wait for others to chime in, as i'm not as clued up as them but a small ammount of heat won't do any harm

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

Good idea, ill give it a go. maybe some small caps on the main boad.iv not inspected fully as the battery on my cap tester and multi meter low and dont want to give false readings

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

ok. im having a steady 27.3 v to the inverterboad yet the backlight remains off.
I have visually inspected the transformers they look ok, iv checked the small fuses they test ok.
ill fully test tomorrow when i have fresh batterys.

[budm]

Re: samsung le32s86bd main board or psu fault?

Post good clear pictures of the boards, model number of the power supply board BN-XXXXX????
Also check your batteries of your meter, when batt is low, the meter read out will be higher than normal . The backlights will not come on until the inverter gets the BL_ON (or INV ON) from the main board. You can try disconnecting the cable between the power supply and the main board to see if the backlights will come on, it may have built-in pull up resistors on the power supply board.

[tom66]

Re: samsung le32s86bd main board or psu fault?

Many backlight inverters have an over voltage circuit which engages after about 26V to shut off the inverter.

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

OK-
The reading i get from the rail from psu, leading to the main board (after fresh battery in meter!)

1 n/c actual 0.0
2 13v " 12.2
3 13v 12.2
4 gnd 0.0
5 5.3 5.2
6 5.3 5.2
7 5.3 0.0
8 5.3 0.0
9 gnd 12.0
10 gnd 0.0
11 gnd 5.2
12 12v 3.4

these readings seem odd where ground is getting 12v?
im wondering, is whats printed onm the psu what is ment to be coming out that rail?

[selldoor]

Re: samsung le32s86bd main board or psu fault?

What did you get on the 24v connector

What are you using as ground- should be a ground screw

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

i was using a spare screw hole on the panel frame.
what do you mewan on the 24v connector? to the inverter board? i think it was 24.4 after i put the new batterys in my meter as previously i had 27! my meter was flashing the battery change icon to be fair!

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

same reading as above using the earth screw with the earth wire attatched.
same reading from the inverter 24.4

bn41-00879b i think is the main board number

[tom66]

Re: samsung le32s86bd main board or psu fault?

Unplug the main board, do you get 12V and 13V stable?

[selldoor]

Re: samsung le32s86bd main board or psu fault?

i was using a spare screw hole on the panel frame.
what do you mewan on the 24v connector? to the inverter board? i think it was 24.4 after i put the new batterys in my meter as previously i had 27! my meter was flashing the battery change icon to be fair!

Yes that is what I meant - you didnt report the retest with new battery

[budm]

Re: samsung le32s86bd main board or psu fault?

"1 n/c actual 0.0
2 13v " 12.2
3 13v 12.2
4 gnd 0.0
5 5.3 5.2
6 5.3 5.2
7 5.3 0.0
8 5.3 0.0
9 gnd 12.0
10 gnd 0.0
11 gnd 5.2
12 12v 3.4"
Still not providing us the pictures and the model number of the power supply board.
Can we see the pictures of this connector? Is it double-row pin? It is missing the ps_on , bl_on (inv on) label, etc.

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

do thewse pics help?
ill a\dd more wehwen im back, im getting dragged shopping!

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

Ok, another question...would a faulty tcon cause the backlight to remain off?
When the tv was on it worked fine, i moved it thern the screen filled with vertical lines. Now the tv is just cycling again, any help wouild be appreciated

[multimeter]

Re: samsung le32s86bd main board or psu fault?

Ok, another question...would a faulty tcon cause the backlight to remain off?
When the tv was on it worked fine, i moved it thern the screen filled with vertical lines. Now the tv is just cycling again, any help wouild be appreciated

no,you would just have a white screen,from the backlights with no tcon

reseat the ribbons on the tcon and mainboard

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

Tv still cycling with no backlight now.
When the tv is cycling i dont have any output from oth b/l output from the psu although the pin next to it called the on/off has a 3.5 the 24v detect also has 5.4

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

Ok. The tv has been cycling for 10 min now the backlight has come on. The b/l pin now has 5.2 v.

[multimeter]

Re: samsung le32s86bd main board or psu fault?

Ok. The tv has been cycling for 10 min now the backlight has come on. The b/l pin now has 5.2 v.

that sounds like cap issues,have you heated the board to see if the fault dissapears?

[charlierfc]

Re: samsung le32s86bd main board or psu fault?

What board, the psu? Or the main board.
I do have a capacitence tester...and a hair drier lol, but its hard to pin point as it sometimes works strait away. Would a cap problem cause screen distortation? Last time it cam on with bit of yellow distortation allomg the screen. Its fine this time though