Overload protection

[verkkotalo]

What happened to the device? Is this a warranty case? Yesterday the same chip read normally, but today these problems. I use a clips.
Test done without a chip

[verkkotalo]

Doesn't read and write correctly

[ArT]

Protection buffers are damaged. This type of damage is not a warranty case, because buffers protects from wrong connection and short circuit. When you program in external circuit with clip, programmer can not limit external current and in case of wrong connection all high current is going through buffers and they can be damaged and need replacement. Pleace check similar case here:
viewtopic.php?f=22&t=401&p=2002&hilit=%2Acb3q%2A#p2002
You can replace it for your own (details in above topic) or you can send programmer to our service - in such case please contact with me via PM for details.

[verkkotalo]

Do I need to change all SN74CB3Q3245PWR or is it enough to change only one?

[ArT]

You should replace all 4 at once because it may not work properly if you replace only one (even if hardware test pass after repair). Buffer for 25xx devices is second (2 from 4) counting from processor side, if you are programming only 25xx devices you do not have to solder 1st, 3rd and 4th but old buffers should be removed.