Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm up

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

Update.

Well, this is the final stage for this board. In the picture I'm showing the pc fan that I put on top of the shield, so now the tv stays on and I can watch ext 1/2 and hdmi. DTV is not possible.

I think I'll get a new board soon but for now, this is ok.

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

I think You need to re-ball the BGA chips

Yep, I'm also thinking about this solution, but obviously I prefer to get a board for that money.

Now I have a fan pointing to the shield (I can keep it) but in fact after several trials I think the critical point is the chip in the red circle: IC3101 IC-DECODER;STI5105,PBGA,324P,23x23mm,PLA

So, that is the final stage I think, with the usb fan like in the second pic:
- DTV mode no signal from the antenna
- Ext 1 (RGB), perfect image
- Ext 2 (AV), image pumping the colors
- HDMI 1, a bit cut at the bottom
- HDMI 2, perfect

Now I'm looking for buying a cheap pc fan and put it inside, more quiet, because the chinese one that I have now is like a drone in a room.

Is it possible to take the power from any point of the tv without stressing or anything (12DCV)?

[timoaito]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

I think You need to re-ball the BGA chips

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

You can force psu and backlights on

How could I do that? Because as soon as I disconnect the mainboard, the led goes off and tv doesn't power up.

Update.

Now with the usb fan pointing to the shield area (removed) tv stays on again, i wasn't able last night. But as soon as I take the fan away the cycle begins, it doesn't admit any temperature.

Also, in dtv mode, when pressing one or two chips on the shield area, I can get the no signal image properly, because sometimes it freezes before the reboot. But in RGB the color pumping issue remains.

I will end up ordering the board anyway so we can voodoo this one looking for a solution XD. I'm opened to oven methods also if required xDDD

[dskall]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

You can force psu and backlights on

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

Is there any way of turn the tv on with the mainboard disconnected? Like shorting some pins or anything, and check if the tv stays on only with the psu

[dskall]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

32" hard to justify spending to much on it.

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

Well, I bought a usb fan but I still can't keep the tv on all the time, or it's not relevant the temperature, i don't know.

If this was my tv i would probably try to source a replacement mainboard as faults are hard to locate on any mainboard.

Yep, there are a couple on ebay around £35 + shipping but I want to be 100% sure that it's the main board and don't waste money.

[vinceroger69]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

If this was my tv i would probably try to source a replacement mainboard as faults are hard to locate on any mainboard.

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

That board is a mess. Were the heat pads gone for those chips?

Those pads are on top of both chips (red circles in picture 1) touching all the time, they always were there, and the shield can't go any deeper, it's in its position already so I guess the pads are touching the chips.

[dskall]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

That board is a mess. Were the heat pads gone for those chips?

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

New update:

I tried cooling down mainly the main board with a manual fan xD (FML) and I can get the tv on.

Now, without stopping, DTV mode image is perfect, no lines, BUT I can't find any channel, it tells me to check the antenna conexion. In RGB mode, the color pumping remains, and in AV mode image is perfect as always.

Under the shield T5 labelled there are two chips with a sticky liguid and a square thing on top to refrigerate. Could it be a problem there?

I don't know, Ill try to get a fan from a pc and narrow the problem down a little bit more later.

Edit: I've attached some pictures, one half of a chip is dry

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

I just did an eeprom reset now but no result.

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

Are you losing ON/OFF voltage as it cycles?

Yes, it goes to 0V for one-two seconds because tv powers off, and once it starts voltage goes to 3.41V right away.

[dskall]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

Are you losing ON/OFF voltage as it cycles?

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

There you go, connector from ps to main board.

01 - ON/OFF - 0V - 3.41V
02 - N/C (No conexion) - 0V - 0V
03 - Standby - 5,21V - 5.22V
04 - S-GND - 0V - 0V
05 - GND - 0V - 0V
06 - GND - 0V - 0V
07 - 12V - 0V - 11.97V
08 - 12V - 0V - 11.99V
09 - GND - 0V - 0V
10 - GND - 0V - 0V
11 - GND - 0V - 0V
12 - GND - 0V - 0V
13 - 5.3V - 0.65V - 5.36V
14 - 5.3V - 0.65V - 5.36V
15 - 5.3V - 0.65V - 5.36V
16 - 5.3V - 0.65V - 5.36V
17 - GND - 0V - 0V
18 - GND - 0V - 0V
19 - 13V - 0.71V - 12.10V
20 - GND - 0V - 0V
21 - 13V - 0.71V - 12.10V
22 - 13V - 0.71V - 12.10V
23 - N/C - 0V - 0V
24 - N/C - 0V - 0V

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

Need these

voltages from connector that goes from power supply board to main board. Will need pin#- PIN DESCRIPTION -Pin voltage in standby-Pin voltage when pushing power button and picture of connector on power supply board.
Format:
Pin# - Pin Description - Pin Voltage standby - Pin voltage power on
1 - XXXXXXX - XXv - XXXv
2 - XXXXXXX - XXXv - XXXv
3 - XXXXXXX - XXXv - XXXv
4 - etc.

Ok, I already measured that connector and the other one of 5 pins coming back from main board to ps and all were ok, maybe I'm missing something, so, give some minutes and I'll check again to post it.

[dskall]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

Need these

voltages from connector that goes from power supply board to main board. Will need pin#- PIN DESCRIPTION -Pin voltage in standby-Pin voltage when pushing power button and picture of connector on power supply board.
Format:
Pin# - Pin Description - Pin Voltage standby - Pin voltage power on
1 - XXXXXXX - XXv - XXXv
2 - XXXXXXX - XXXv - XXXv
3 - XXXXXXX - XXXv - XXXv
4 - etc.

[Leplus]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

What voltage are you getting on your ps-on while rebooting?

Mmmmm, you mean at the entrance? AC volts? Or any other point?

At the entrance I'm getting 234acV steady all the time. I can measure whatever you need haha, or connectors or the inverter (but I don't know where to measure exactly there so I didn't try there), I just run out of ideas.

I found another thread about this similar problem but they don't say the solution, just check the LVDS cable or the inverter, but without them disconnected the tv is still rebooting, so I didn't check them and I focused on the ps and the main board.

I also asked in a couple of youtube videos with the same issue but I don't expect them to reply, I'll wait anyway.

[dskall]

Re: Samsung TV LE32M87BD image issue, turns off by itself, works perfectly after warm

What voltage are you getting on your ps-on while rebooting?