RT809F ZIF socket operation

[kevin_allein]

Hi, I bought a RT809F from China. When I connect it to a LCD Monitor with HDMI, it auto detects the EEPROM and can read and program it.
However I have 2 different 8 pins EEPROMs and wanted to read them out. It neither detects the ICs correctly, nor can it read them even if I select the device.
If I measure voltage between pin 4 (GND) and 8 (VCC), I measure 0V. Obviously operation cannot work without voltage.

Any tips what I am doing wrong ?

[mon2]

Which eeproms are not being detected properly? Which part #?

It is possible that the s/w or hardware logic is checking for a nominal current draw from a seated memory device else will power down. The meter leads are not imposing a suitable load so the Vcc remains off. Perhaps quickly pulsed on and then off and the meter is unable to sample this rapid ON/OFF cycling.

https://www.eevblog.com/forum/review...sh-programmer/

[kevin_allein]

I have tried two different devices, one is a 24C16, the other one 25040. Both are neither recognized in the socket nor can be read when selected manually

[mon2]

Post a clear pic of one of these ICs as seated in your programming tool for a review.

[mcplslg123]

What is mentioned on the ZIF socket markings. The size may be the issue.

[kevin_allein]

this is an image from the RT809F manual. My setup is identical

[mcplslg123]

The ZIF socket comes in 2 sizes 150mil/200mil.

150mil is the size for 24xx/25xx series eeproms.

[kevin_allein]

The leads make contact and I cannot measure any VCC voltage. I don't understand your comment

[m1ch43lzm]

The leads make contact and I cannot measure any VCC voltage. I don't understand your comment

Likely VCC gets enabled only when reading/writing, try sticking wires on the socket, attached to your multimeter leads
If your meter has auto range, switch it to manual range (10-20v), then try to read the chip, you should see the voltage appear only when reading the chip
If you have an old desktop PC motherboard laying around with a DIP8 25xx flash, try it, that's to rule out if your ZIF socket, or programmer is defective

[mon2]

Likely VCC gets enabled only when reading/writing,

As noted in post # 2...

Given that this was a new product purchase, what did the vendor report? What did the manufacturer's tech support team report?

[kevin_allein]

I have an endless chat with that chinese company, however not very helpful. They ask for more and more videos and pictures, but no real help.
In the meantime I remembered that I have a CH341A. I used the same adapter sockets and same ICs in that and it could read the two ICs I tried. So it is definitely a problem with the RT809F, not a bad IC or a bad adapter socket.

[mon2]

If there are no warranty seals, open it up to review. Perhaps a dry solder issue. Really should be returned to the vendor but may be easier to repair than to return.