Hot, 25pe40vp chip (U2)

Discussion about Z-Uno product. Visit http://z-uno.z-wave.me for more details.
Geirbakke
Posts: 22
Joined: 22 May 2017 16:09

Hot, 25pe40vp chip (U2)

Post by Geirbakke »

Have anyone experience the Flash chip 25pe40vp to become extremely hot?

after some seconds the chip gets burning hot and the z-uno stops working.

-Geir
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PoltoS
Posts: 7565
Joined: 26 Jan 2011 19:36

Re: Hot, 25pe40vp chip (U2)

Post by PoltoS »

What are you using to power Z-Uno?

Was it from the very first day or Z-Uno was working properly some time?

After what time does it become too hot and stoops working?

M25PE40 is the FLASH and should not be hot.
Geirbakke
Posts: 22
Joined: 22 May 2017 16:09

Re: Hot, 25pe40vp chip (U2)

Post by Geirbakke »

Hi I’m using 12v car battery

I removed the zuno from the bread board and I gets hot (burning) even on usb connection, about 30 sec.

I have not notis the problem beefore but until now I have only, been doing developments and it has not been on for more than a short time.
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PoltoS
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Joined: 26 Jan 2011 19:36

Re: Hot, 25pe40vp chip (U2)

Post by PoltoS »

How have you connected 12 V?

Is Z-Uno working at least these 30 sec? Can you Flash it in this period?
petergebruers
Posts: 255
Joined: 26 Jul 2015 17:29

Re: Hot, 25pe40vp chip (U2)

Post by petergebruers »

What is connected to the Z-Uno pins? Is it possible to post a schematic? Did you, at any time, have anything connected to a pin that can pull the pin higher than about 3.4 - 3.6 V and can deliver more than 10 mA of current? That can cause trouble, although I'd expect not only the flash chip to heat up, but also the SoC...
Geirbakke
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Joined: 22 May 2017 16:09

Re: Hot, 25pe40vp chip (U2)

Post by Geirbakke »

Hi, I disconnected the z-uno, And wirhout any external connections it still heats up.

The flash is the only chip thats to hot to touch.
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PoltoS
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Joined: 26 Jan 2011 19:36

Re: Hot, 25pe40vp chip (U2)

Post by PoltoS »

Please answer to all questions above. It is hard to help if you answer only to some questions.

As petergebruers mentioned, if you have connected at least once something that exceeded Z-Uno voltage, you might have burned some chips and now it will be damaged and heat up even when everything is disconnected.

Please respond to the questions to help us understand what happened and then we can proceed to suggestions about fixes: if only FLASH is damaged by this high voltage, you can replace it (this is a chip you can easily buy). But if something else is damaged too, Z-Uno is more likely to be dead.
petergebruers
Posts: 255
Joined: 26 Jul 2015 17:29

Re: Hot, 25pe40vp chip (U2)

Post by petergebruers »

@Geirbakke, In understand, what you are saying.

But my question is: *before* you disconnected everything, did you have anything connected to a pin, which can pull the pin higher than about 3.4 - 3.6 V and can deliver more than 50 mA of current (I wrote 10 mA in my previous post because that is the spec, but you need more current than the spec to kill it. I am not going to try how much but exactly...)? Did you accidentally connect a 5 V sensor or a 5 V device to one of the Z-Uno pins? Damage may be permanent... Let us hope not... As PoltoS said, can you please help us to understand what happened by telling a bit more?

Please measure the voltage between ground and the "3V" pin (4th pin from the top left on your board). It should be 3.1 - 3.2 Volt. What do you read?

Do you have a lab supply? You could set it to 3 V and 50 mA max and power the Z-Uno by the 3V pin only, without anything else connected to the board.

And as PoltoS asked:

How have you connected 12 V?

Is Z-Uno working at least these 30 sec? Can you Flash it in this period?
Geirbakke
Posts: 22
Joined: 22 May 2017 16:09

Re: Hot, 25pe40vp chip (U2)

Post by Geirbakke »

Hi, I will post a schematic (just have to draw one first)
measuring the pins I can't do until tomorrow my measurement instrument needs battery.

Yes, I can't flash the Z-uno before it dies.

To summon the connections, i had 6 inputs where I use ground for signal
I had 4 relay outputs, and 6 led outputs. The relay where connected with a ULN2003 for reversing the signal.

the 12V power connected to the first pin 7-18V
petergebruers
Posts: 255
Joined: 26 Jul 2015 17:29

Re: Hot, 25pe40vp chip (U2)

Post by petergebruers »

Thanks. Was it a stand-alone 12 V battery or was it 12 V in a car? A car can produce large transients, I would add an extra regulator (for cars!) between your Z-Uno and the car output...

The input circuit will be important, and also we have to consider inductive kickback from the relays (check pin 9 = COM of the ULN2003).

Anyway, your schematic will make this discussion easier... Just doodle it on a piece of paper, with a pencil!
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