Dell LA-G712P MEC1416-NU

[mcplslg123]

I have one dell LA-G712P. Problem is not detecting battery. On diagnosis, found CLK line is pulled low to 0.85V. Replaced charger IC but still same. Resistor connected to SIO SDA/SCL pins are 4.7K-so fine/Resistors connected to SDA/SCL battery pin connectors are 100 Ohms-so fine. So i think SIO is defective.Adapter is correctly identified-so PS_ID is fine.

SIO used on mb is MEC1416-NU but i dont have it. I've MEC1418-NU in stock. Are they replaceable?? I've gone through datasheet and MEC1416 Sram is 160KB while MEC1418 has 192KB as SRAM. There is no other difference.

Whats your opinion guys??

[mon2]

Re: Dell LA-G712P MEC1416-NU

Is the pull up voltage present on the I2C SCL open drain line?

Check if there are any esd diodes near the battery connector which may be damaged.

With 100 ohm resistors, they will be to current limit these communication lines and therefore can be removed to isolate the circuit. Then can confirm if the bus master SIO is at fault and unable to clock this I2C line.

Is this SIO programmable? From some quick past reviews, these devices have an internal 8051 microcontroller. So firmware may be required to become the I2C bus master.

[mcplslg123]

Re: Dell LA-G712P MEC1416-NU

Yes, 3V is available as pullup. SIO is programmable and i've already reprogrammed it. There is no ESD diodes-all are @. I tried removing 100 Ohms resistors as well but result is same. SCLK still pulled low at 0.85V.

Since no one confirmed about my question, i think i'll wait and order the same SIO MEC1416-NU.

[anshad]

Re: Dell LA-G712P MEC1416-NU

Yes, 3V is available as pullup. SIO is programmable and i've already reprogrammed it. There is no ESD diodes-all are @. I tried removing 100 Ohms resistors as well but result is same. SCLK still pulled low at 0.85V.

Since no one confirmed about my question, i think i'll wait and order the same SIO MEC1416-NU.

To my knowledge, this SIO doesn't have internal flash but SRAM which will be loaded with EC firmware from main BIOS on startup. Isn't a power cycling enough to reload the EC firmware ?. Am i missing something ?

[mcplslg123]

Re: Dell LA-G712P MEC1416-NU

@anshad, you are right but thats only when the SIO is blank. It wont program itself from main if EC Sram has data. So i just erased it with SVOD and put clean me bios so that it can program itself on 1st boot. Since laptop is giving display, i think nothing wrong with erase.write of SIO.

PS: Will receive new SIO within a day or two. Will update the forum about result,if any.

[mon2]

Re: Dell LA-G712P MEC1416-NU

@mcplslg123, before replacing the sio chip, can you check the I2C pins in diode mode?

Then interested to know the same diode readings of the fresh sio controller.

[mcplslg123]

Re: Dell LA-G712P MEC1416-NU

New sio soldered.Problem is solved and it is detecting battery now. SCLK is now 3.3V which was earlier pulled low at 0.85V.
@mon2, i already delivered it to customer, so cant give measurements anymore.

[usyusy]

Re: Dell LA-G712P MEC1416-NU

sir, are "EC BIOS" and "Program of a SIO" different things?

2ndly if replace any IO even from same other board should we program it?

[mcplslg123]

Re: Dell LA-G712P MEC1416-NU

No need to program if SIO is taken from same motherboard. EC bios and program of Sio is usually same.

[jacobk1508]

Re: Dell LA-G712P MEC1416-NU

I replaced the MEC1418-NU from a board of another model, it worked immediately and I didn't need to do anything else. I think everyone just needs to change 1 MEC with the same code

[Microm]

Re: Dell LA-G712P MEC1416-NU

New sio soldered.Problem is solved and it is detecting battery now. SCLK is now 3.3V which was earlier pulled low at 0.85V.
mon2, i already delivered it to customer, so cant give measurements anymore.

Hello, I have a question. I also have an issue with the MEC1416 in a Dell laptop. In my case, the keyboard is not working, so my question is, if I replace it, do I need to reprogram the MEC? Or is the BIOS sufficient? If it is reprogrammable, how did you perform the procedure? Thanks in advance.

[mcplslg123]

MEC1416 will program itself frrom main bios. recommended to put a clean me bios after sio replacement and then only connect power.

[Microm]

MEC1416 will program itself frrom main bios. recommended to put a clean me bios after sio replacement and then only connect power.

Hello, I just replaced the MEC1416 integrated circuit in the Dell laptop, which was having an issue recognizing the keyboard, and now the laptop doesn't turn on. Its initial power consumption is only 0.016mA and it doesn't power on... I assume it's due to some programming issue. Could you help me with this?

[mcplslg123]

MEC1416 doesnt need programming manually,so either the SIO you soldered is bad or not soldered properly

[Microm]

MEC1416 doesnt need programming manually,so either the SIO you soldered is bad or not soldered properly

Hello! I changed the MEC1416 and now it turns on, but it still has the issue of not detecting the keyboard. Any other questions? I already changed the keyboard.

[mcplslg123]

You have not mentioned the mb markings for your laptop-so nothing can be suggested.

[Microm]

You have not mentioned the mb markings for your laptop-so nothing can be suggested.

Dell Inspiron P93G Service Tag 6V4T4P2

[mon2]

No. Requesting the white silk screen markings which may be something like 'LA-****'. Or you can take and post pics of the motherboard.

[Microm]

No. Requesting the white silk screen markings which may be something like 'LA-****'. Or you can take and post pics of the motherboard.

bucky/ben solo whl/cnl mb tvmhg 17859 This is the model.

[Microm]

Re: Dell LA-G712P MEC1416-NU

anshad, you are right but thats only when the SIO is blank. It wont program itself from main if EC Sram has data. So i just erased it with SVOD and put clean me bios so that it can program itself on 1st boot. Since laptop is giving display, i think nothing wrong with erase.write of SIO.

PS: Will receive new SIO within a day or two. Will update the forum about result,if any.

Hello friend, could you tell me the procedure and pins that you soldered to clean the MEC1416, (TDO, TDI, TMS and TCLK)