Toshiba 46sl417u main board issue

**CapLeaker** · 10-25-2015, 10:11 AM

Re: Toshiba 46sl417u main board issue

That sux.

**shadetreetrader11** · 10-25-2015, 05:07 PM

Re: Toshiba 46sl417u main board issue

ya i agree that sucks.

**mattstolte** · 10-25-2015, 05:31 PM

Re: Toshiba 46sl417u main board issue

You wont find that main board anywhere. I had to send it to modus link to get repaired but there closed down now. I got a guy that can repair that main board he is great with them Toshiba's and had a test set. So if he's able to Do it then anyone can its just knowing how to do it which I dont

**shadetreetrader11** · 10-26-2015, 04:55 PM

Re: Toshiba 46sl417u main board issue

I guess I'm a little confused as to who is working for badcaps.net? Who can I get a quote from for mainboard repair? Am I obligated to pay for the advice I recieved from leaky caps? Or is the idea that I purchase all my parts threw badcaps? I've never done this before, so i need a 101 on the whole concept.

**CapLeaker** · 10-26-2015, 06:09 PM

Re: Toshiba 46sl417u main board issue

Well no... there are some real smart members on here that are sharing their experiences and their wealth of knowledge to those that need help for free. However if you like you can donate to badcaps.net to help keep this forum going. Parts you can get wherever you want, that is up to you. Digikey, Mouser, Ali, wherever...

**fzabkar** · 10-26-2015, 09:22 PM

Re: Toshiba 46sl417u main board issue

I would measure the voltages at the regulators on the main PCB.

IC273, D2907, L2707, C2738, C2732, C2735 constitute a stepdown DC-DC converter. Measure the output voltage across the capacitors (C2738, C2732, C2735).

IC290, D2910, L2900, C2907-2910 constitute another stepdown DC-DC converter. Measure the output voltage across the C2109- C2107 capacitors. These are just after the FL285 inductor.

IC313 appears to be a linear regulator. Measure the voltage at the 100uF smd capacitor just below it.

There appear to be 3 more stepdown regulators near the CPU. Measure the output voltages at each of the 3 coils.

There is at least one more stepdown regulator near the tuner. Measure the output voltage across the C2705, C2707, C2708 capacitors, and the voltage on the other side of FL174.

There could be more regulators (IC327 ?), but I can't see the PCB clearly enough in any of the photos.

**budm** · 10-26-2015, 09:38 PM

Re: Toshiba 46sl417u main board issue

Did you already try heating (hair dryer) and cooling (using canned air duster upside down) the board?
Try disconnecting the WIFI card?
Pictures provided by shopjimmy.

Attached Files

**mattstolte** · 10-27-2015, 02:43 PM

Re: Toshiba 46sl417u main board issue

Originally posted by fzabkar

I would measure the voltages at the regulators on the main PCB.

IC273, D2907, L2707, C2738, C2732, C2735 constitute a stepdown DC-DC converter. Measure the output voltage across the capacitors (C2738, C2732, C2735).

IC290, D2910, L2900, C2907-2910 constitute another stepdown DC-DC converter. Measure the output voltage across the C2109- C2107 capacitors. These are just after the FL285 inductor.

IC313 appears to be a linear regulator. Measure the voltage at the 100uF smd capacitor just below it.

There appear to be 3 more stepdown regulators near the CPU. Measure the output voltages at each of the 3 coils.

There is at least one more stepdown regulator near the tuner. Measure the output voltage across the C2705, C2707, C2708 capacitors, and the voltage on the other side of FL174.

There could be more regulators (IC327 ?), but I can't see the PCB clearly enough in any of the photos.

Man that was alot of smart info. Would love to get to that level one day. Still learning

**fzabkar** · 10-27-2015, 03:01 PM

Re: Toshiba 46sl417u main board issue

It's not really that complicated.

The main board is based around an SoC (System on a Chip). The SoC and its peripheral components (eg SDRAM, EEPROM, flash) run from lower voltages. For example, the SDRAM typically requires 1.8V, the EEPROM/flash requires 1.8/2.5/3.3V, and the SoC requires a Vio voltage (3.3V) and a Vcore (~1V - 2V).

These voltages are generated from the main supply by switchmode DC-DC converters or linear regulators. You can identify the switchmode converters simply by looking for coils. In a stepdown converter the output voltage will be present at the coil. A linear regulator typically has 3 pins, Vin, Vout, and Vadjust or Ground.

When testing a CPU based board, you first check the onboard supplies. Then you look for the reset signal at the SoC and verify that the oscillator (usually a crystal or crystal oscillator) is functioning.

**CapLeaker** · 10-27-2015, 04:03 PM

Re: Toshiba 46sl417u main board issue

Originally posted by mattstolte

Man that was alot of smart info. Would love to get to that level one day. Still learning

yeah... but at that level you need a hot air soldering station too... I have one, but most don't.

**shadetreetrader11** · 10-27-2015, 08:48 PM

Re: Toshiba 46sl417u main board issue

Originally posted by fzabkar

It's not really that complicated.

The main board is based around an SoC (System on a Chip). The SoC and its peripheral components (eg SDRAM, EEPROM, flash) run from lower voltages. For example, the SDRAM typically requires 1.8V, the EEPROM/flash requires 1.8/2.5/3.3V, and the SoC requires a Vio voltage (3.3V) and a Vcore (~1V - 2V).

These voltages are generated from the main supply by switchmode DC-DC converters or linear regulators. You can identify the switchmode converters simply by looking for coils. In a stepdown converter the output voltage will be present at the coil. A linear regulator typically has 3 pins, Vin, Vout, and Vadjust or Ground.

When testing a CPU based board, you first check the onboard supplies. Then you look for the reset signal at the SoC and verify that the oscillator (usually a crystal or crystal oscillator) is functioning.

I don't have a schematic for this board I did go around and test a bunch of the sections of the main board and found the voltages you mentioned in your last post. what I am lacking is the 12v on the t-con connector cn652 pins 1-4. how do I check some of the oscillator functions? That might be getting a little deep. I have a scope and hot air soldering station also if that helps.

**shadetreetrader11** · 10-27-2015, 08:50 PM

Re: Toshiba 46sl417u main board issue

Originally posted by budm

Did you already try heating (hair dryer) and cooling (using canned air duster upside down) the board?
Try disconnecting the WIFI card?
Pictures provided by shopjimmy.

I tryed heating and cooling, and disconnecting the wifi card with no luck.

**fzabkar** · 10-27-2015, 09:01 PM

Re: Toshiba 46sl417u main board issue

Your voltage readings are unhelpful. Sorry, I can't help you.

**shadetreetrader11** · 10-27-2015, 09:06 PM

Re: Toshiba 46sl417u main board issue

Well i really need some test points and there required voltages

**shadetreetrader11** · 10-28-2015, 08:47 PM

Re: Toshiba 46sl417u main board issue

Originally posted by mattstolte

You wont find that main board anywhere. I had to send it to modus link to get repaired but there closed down now. I got a guy that can repair that main board he is great with them Toshiba's and had a test set. So if he's able to Do it then anyone can its just knowing how to do it which I dont

Can you please tell me how to get ahold of your friend that works on these main boards?

**shadetreetrader11** · 11-03-2015, 07:28 PM

Re: Toshiba 46sl417u main board issue

Originally posted by fzabkar

Your voltage readings are unhelpful. Sorry, I can't help you.

Is there anyway you can give me some test points and voltages so I have a little direction to go hear. If it helps you I can go through all the caps you mentioned and tell you there voltages.

**fzabkar** · 11-03-2015, 10:05 PM

Re: Toshiba 46sl417u main board issue

The capacitors I mentioned are the test points that I would be looking at. So yes, their voltages would be helpful. A close-up photo of the three coils would help too.