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EPROM Chip help

Posted: 02 Oct 2020, 02:54
by kbTinker
Does anyone on here possess the programming knowledge and tools to test, read and write EPROM chips? I ask because on my Mextel AutoKey 40 macro accessory board there is a EPROM chip with a quartz window on it. I think that this chip is what was used to store the boards operation programming and over many years and due to prolonged UV exposure, the programming stored on the chip has either become erased or partially corrupted.

I say this because, try though as I may, I cannot seem to get the board to work as it was designed. I checked the entire board for any corrosion or damage, finding only a small amount of corrosion built up on one of IC chips, which was easy to clean off. I did purchase a new IC chip to replace it, in case that one has been damaged internally due to the corrosion before I cleaned it.

In other words, I was wondering if I could perhaps send my AutoKey to someone who knows what they are doing for them to trouble shoot the board and figure out where the issue is. Like I said before, I have a nagging feeling that the EPROM chip is the culprit for the problems. If someone is willing to help, I will gladly pay for shipping, both ways.

Below is a photo of the EPROM chip on the motherboard, beneath the sticker is the quartz window.

Re: EPROM Chip help

Posted: 10 Oct 2020, 13:55
by DMA
UV-eraseable EEPROMs slowly lose stored charges and turn to unprogrammed state. That's unrecoverable. You can reprogram it, but you are highly unlikely to find ROM dumps and/or original code, even if the company that made it is still in business.

If you have traditional, electrical-contact switches, it's not that big of a problem - just replace with something contemporary with firmware of your choice. You can even just replace the MCU, leaving everything else intact.