Toshiba 42HL196 No power 3 blinking lights, possible Seine board

[rmoody]

I picked up this 42" toshiba LCD the other day and i'm getting around to checking it out. When the power button is pushed I'm getting 3 red flashes from the front led, then a pause and 3 more flashes. Checked under the hood and just shook my head, crap load of ugly boards inside this bugger. Either way. I checked my PS rails and i'm only getting the 5V stdby voltage. The ps_on pin isn't picking up a voltage. Typically I would look at the main board next but this one is different. It is loaded with different boards. It has the PS board, a "Lower B" board(someone please tell me what this is for, located in middle of tv with brown PCB), Seine (Main/Logic) board and another input board on the left side of tv.
I've removed the Seine board and didn't find the typical LDO regulators that sometimes fail on a main board and basically everything on it is too small for me to replace. I'm thinking the PS_On is supplied through this (Seine) board but i'm not sure and want some input from the pro's here.

Thanks in advance.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

OK, I've found a pretty good manual from scribd with a nice flow chart and found that on pin 8 from the AV/terminal board to the LOWB board on P812A is reading a bit low. It is supposed to be reading 3.3 and it's reading 3.15V. Not sure if this is low enough to be my problem or not but seems kinda low to me.

[retiredcaps]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

It is supposed to be reading 3.3 and it's reading 3.15V.

Most regulators have a +/-1% specification. Your reading is close to 5% out so i would say it is bad unless your multimeter is really out of whack.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

Most regulators have a +/-1% specification. Your reading is close to 5% out so i would say it is bad unless your multimeter is really out of whack.

I was thinking 1% but wasn't sure. MM is good

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

tried tracing the pin down but lost it and can't figure out where it goes, kind of looks like it goes to a small 40 pin IC. This board has a 5 pin transistor on it. How do I test it?

[retiredcaps]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

This board has a 5 pin transistor on it. How do I test it?

For transistors, I do a simple in circuit test for shorts. Any reading under 30 ohms warrants desoldering and verifying out of circuit.

Without knowning the part number, the easiest way would be to number the pins 1,2,3,4, and 5. Test 1-2, 1-3, 1-4, 1-5, 2-3, 2-4, 2-5, 3-4, 3-5, and 4-5.

It would be wise to look for its datasheet because some pins may be shorted on purpose.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

For transistors, I do a simple in circuit test for shorts. Any reading under 30 ohms warrants desoldering and verifying out of circuit.

Without knowning the part number, the easiest way would be to number the pins 1,2,3,4, and 5. Test 1-2, 1-3, 1-4, 1-5, 2-3, 2-4, 2-5, 3-4, 3-5, and 4-5.

It would be wise to look for its datasheet because some pins may be shorted on purpose.

1-2 is showing shorted but like you said it may be intentionial. I'm horrible at finding datasheets but I'll check it out again.

Heres the numbers on it.
00jc5w
636 h59

[Th3_uN1Qu3]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

It's a 1.5A low dropout regulator. http://www.alldatasheet.com/datashee...BA00JC5WT.html

What voltage do you get on its output? That 3.15v doesn't sound like a bad reg, more of a bad capacitor after the reg, or one of the parts it is feeding drawing excess power.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

It's a 1.5A low dropout regulator. http://www.alldatasheet.com/datashee...BA00JC5WT.html

What voltage do you get on its output? That 3.15v doesn't sound like a bad reg, more of a bad capacitor after the reg, or one of the parts it is feeding drawing excess power.

Yeah I found that datasheet but it's labeled on the board with a Q, I thought a Q was always a transistor???

Got the board out right now, gonna reinstall it and check the voltages of it now.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

I'm getting .382v on pin 1 and 2, 3 is my ground and 4 and 5 have 0 voltage.

[Th3_uN1Qu3]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

You don't have the right input voltage, where is the input of this reg coming from? Input should be 5v or 3.3v. As for the output, the control pin is also low, so the regulator is in shutdown mode, hence the output is zero.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

You don't have the right input voltage, where is the input of this reg coming from? Input should be 5v or 3.3v. As for the output, the control pin is also low, so the regulator is in shutdown mode, hence the output is zero.

gonna trace it down if I can.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

Pin 1 and 2 are reading short so I'm thinking this regulator is trash

[Th3_uN1Qu3]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

Time to unsolder it and see if the short is in the part itself or on the board.

[jackslater]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

Q880 is strw6765 goes bad on those power supplies --turns on 12v to 12volt relay sr81 on power board pe0071g-1 if same -power SUPPLY board -this real common COST 5-12 DOLLARS + SHIP
COMMON FIX FOR DEAD/ AND BLINK LIGHT- will see if fixes mine -part will be here tomorrow.

also -strz-4479-Q860 ,
and srx-2039 Q820

[jackslater]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

Just put strw6765 - set works fired right up - old was was cook to heat sink
rip some pads off PB bottom.

Recommend anyone - new like me unsolder pads before trying to free regulator-

Also note
No more click click click - just two solid click-=when plug in - also had 3.3 on protect line


You also want to replace srx-2039 that factory Toshiba recommend - according to another forum -

[tom66]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

I happen to have a Toshiba 42WLT66 with nearly the same board set which is working properly. I can make some basic voltage measurements if needed before I assemble the set.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

Time to unsolder it and see if the short is in the part itself or on the board.

pulled from board and tested good. Time to move onto something else.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

Just put strw6765 - set works fired right up - old was was cook to heat sink
rip some pads off PB bottom.

Recommend anyone - new like me unsolder pads before trying to free regulator-

Also note
No more click click click - just two solid click-=when plug in - also had 3.3 on protect line


You also want to replace srx-2039 that factory Toshiba recommend - according to another forum -

I really don't think my problem is in the power supply. I'm only getting my 5vstby on the PS. Don't ever get any voltage on the power_sig or Power pin which should be a 3.3v signal to turn the power supply on. Maybe my problem is in the Seine board.

[rmoody]

Re: Toshiba 42HL196 No power 3 blinking lights, possible Seine board

Any other suggestions?