You can only really tell if a EPROM is okay if it can be erased (a blank reads as 0xFF at every address) and then programmed successfully.
Electrolytic capacitors need to have voltage applied to them for a period of time in order to reform (typically measured in hours). But the more common problem is the loss of electrolyte over time (often called "drying up"). If It's the latter, they need replacing.
To fully answer your question, details of the circuitry is needed. But in most common designs, the programmer would just need to be powered up for the programming voltage power supply circuitry to be "running". Then either a manual switch or an electronic switch (transistor) is operated to apply the programming voltage to the VPP pin of the EPROM chip.
Mark
Electrolytic capacitors need to have voltage applied to them for a period of time in order to reform (typically measured in hours). But the more common problem is the loss of electrolyte over time (often called "drying up"). If It's the latter, they need replacing.
To fully answer your question, details of the circuitry is needed. But in most common designs, the programmer would just need to be powered up for the programming voltage power supply circuitry to be "running". Then either a manual switch or an electronic switch (transistor) is operated to apply the programming voltage to the VPP pin of the EPROM chip.
Mark
Statistics: Posted by 1024MAK — Sat Nov 30, 2024 12:09 pm