23201A Serial Adapter Loopback problems

Like others who have posted similar topics, I’m attempting to unbrick a seagate drive. I’ve successfully performed a loopback test on my COM1 port, and on the serial cable when attached. Where I run into problems is performing the test when the adapter is installed inline.

I purchased an adapter, and prior (I’m fairly certain) to frying it, I had verified 4 volts by testing on the solder points of the adapter, while powering it from the PSU of my PC.

I’ve purchased a second adapter, and want to try powering it from a CR2032 battery to avoid the voltage spike issue. To which terminal do I attach my vcc point, and to which do I attach the ground?

Thanks in advance,


4 volts is an uncommon voltage; how did you get it? The battery you’re talking about is a coin cell, right? It won’t last very long, plus you need the voltage to the chip to match what your signals are; if you power the chip at 3V but give it 5V signals, that could also damage it.

Vcc is the positive power input; ground is the negative one.

- Jan

Per your feedback, I discarded my plan to power from a coin cell, and have, with my new adapter, hooked it up and powered from the PC. Power leads are about 8 inches total, voltage is confirmed at 5V (previous 4v reading was a poor multimeter). I am still unable to loopback the adapter, and again, have successfully tested the loopback on my data cable.



You said earlier that you were fairly certain you fried the first one. What was that based on? What is your power supply? Can you post a picture of your setup?

- Jan