HOW TO read all 24C32 epprom? Found 0 device(s)

HI
I have connected it directly w/o resistors / capacitors etc

24c32 - > arduino
red wire to 5v
yellow to A4
orange to A5
blacks to GND
A0..A2 is on GND on pcb I didn't connected it to anything

I have tried this scanner - http://www.gammon.com.au/forum/?id=10896&reply=6#reply6

I2C scanner. Scanning ...
Done.
Found 0 device(s).

Please help how to read data. where is my mistake ?

When you apply power to the EEPROM power pins, are you not also powering the board it's mounted on?

...and... what voltage does the MCU/EEPROM/wireless IC run on? Did you measure it or you know?

are you not also powering the board it's mounted on? - I dont know if all chips/elements are powered.... but power LED is turn on

what voltage does the MCU/EEPROM/wireless IC run on? - should be 5v (as on arduino)

Did you measure it or you know? - no

Don't you think that the on board components are actively accessing the EEPROM when it is powered? That would definitely interfere with another device trying to do the same thing.

Huge blunder to connect 5V to it without knowing the supply voltage. You may have destroyed the board already.

no still working.

I have added pause to start scannning with 30 sec delay... still 0 devices

The fact that it still works does not mean that you have not damaged it. Excess voltages can weaken a device so it appears to work, but will fail later on. If you're not motivated enough to make a simple voltage measurement, I am leaving you on your own.

Desolder and remove the chip from the board?

Or desolder the Vcc pin and lift it off the pad. But I think your board's integrity is compromised now. Don't use it in any critical application.

Could that phantom power the rest of the board through the chip's other pins, damaging the chip and/or the board?

Yes, for example through pull up resistors on the board. But it is less likely.. and the board has already experienced "the full Monty" :slight_smile:

You're right, the SDA/SCL pins are open collector, so they should not be a problem. Does the chip have an address pin connected direct to Vcc...

I have no solder fan . with solder iron I havent enough skill

A0..A2 is on GND on pcb I didn't connected it to anything

I see a 78L05 regulator at the top, so maybe the circuit is 5V. Cannot see any other regulators, but we can only see top side of the board.

at the bottom just odb2 connectors pins

What do you hope to find in the EEPROM? It seems to be connected to the wireless IC.

Some of the small 3 and 5 pin IC's might be regulators. Also I highly doubt that the wireless IC is a 5V part...

The chip is not responding to your attempt to detect it. Perhaps the chip is faulty. Perhaps the rest of the circuit is preventing you from detecting it in some way, like attempting to access it at the same time you are also attempting to access it. Either way, I think you have to remove the chip, it at least the Vcc pin.

I can see you soldered wires to the pins, so your solder skills are not as poor as you think. Do you have a solder sucker?

FYI it is unfortunately really easy to lift and destroy a pad while desoldering an SMT part. It does take some skill and extreme patience to do safely. The easy way, is to cut the leads off first but that destroys the part.

Ah, I missed that one of them has 5 pins: "DE-A10" ?

All the 3 pin chips are marked "H1A" or "2A". There are too many for them to be regulators, I think, so probably just MOSFETs or something.