I would like to buy one, if you make more.
Hi anemo,
I've been looking at the schematics that this device is based on and there's a major flaw in the design. There are neither current limiting resistors nor buffers between the µP and the DUT. This means that if any one of the RAM's pins is shorted to ground (which is extremely common on failed RAMs) the current will instantly exceed the allowed 40mA per pin of the µP and the Arduino is permanently damaged. So the device will only work until it has actually tested a bad chip?!
Bryce.
The PTC only protects the supply voltage to the DUT. Many 4164's that I've removed from countless machines had either an address or data line shorted to ground. These would detroy the tester (the Arduino, not the tester board itself).
Bryce.
Still interested. Payment coming
New batch and upgraded version (v1.2) now available!
New version has Arduino Nano output pins overcurrent protection (if DRAM chip is short circuited).
Slight price increase due to higher component cost and longer time to assemble.
Was €25.5 (v1.0), now €27.5 incl. shipping.
First 5 available boards are reserved for the following guys (in this order) who previously has stated interest in this thread:
* mrr19121970
* botialoach
* SaviorX
* DonChaos
* Knecht
PM sent to each member!
New batch and upgraded version (v1.2) now available!
New version has Arduino Nano output pins overcurrent protection (if DRAM chip is short circuited).
Slight price increase due to higher component cost and longer time to assemble.
Was €25.5 (v1.0), now €27.5 incl. shipping.
First 5 available boards are reserved for the following guys (in this order) who previously has stated interest in this thread:
* mrr19121970
* botialoach
* SaviorX
* DonChaos
* Knecht
PM sent to each member!
Cool, great improvement. How have you implemented the current protection? Series resistors on each pin or have you done something fancy?
Do you have pictures of the new device?
Bryce.
Payment done! PM answered. Thx
Will make payment tonight, still interested.
Will make payment tonight, still interested.
Payment has just been made, Thank you