This is an Arduino based SRAM tester for 2114 memory chips. (4096 bit, 1024 x 4 bits) These chips are commonly used in retro computers & arcade machines from the 80’s.
The PCB features short circuit protection in the form of a resettable fuse and also has 100 ohm resistors in series with each address/data line to protect against damaged chips under test (Shorts to GND or Vcc)
Each memory address is checked multiple times for any errors.
When testing the red and green LED’s alternate indicating that data is being written and read from the chip.
Green LED indicates RAM is working.
Red LED indicates RAM is faulty.
Instructions:
- Insert 2114 into the ZIF socket (Make sure pin 1 is closest to lever. Pin1 marked on PCB)
- Connect mini USB cable.
Testing will start. First the poly fuse checked. If the fuse is blown the red LED will pulse in 1s intervals. (If this happens then the chip under test is faulty and is drawing too much current which has caused the fuse to blow. The polyfuse will reset after it’s cooled down after a few minutes.)
- Flashing red/green indicates test in progress (Data R/W to the chip)
- Red LED means the RAM fails testing and is faulty.
- Green LED means RAM passed. (Test takes approx 45 seconds)
Make sure the orientation of the 2114 is correct. Failure do to so and you risk destroying the chip
The tester does not come with a USB Cable. You will need a mini USB micro type B cable.
Update: A bug was identified in the current firmware which causes specifically 21C14 chips to fail. This has been fixed in v1.1 which is now included in the latest boards.
To update a old board you can see these instructions.
