Burning Nvram ram tune onto my Vn memcal

[Asho88]

It reads fine, I can blank check but it won’t write very annoying.

[antus]

FFFF looks like it might not be working at all. How did you make it? Have you had a soldering iron on the chip pins? Might have melted an internel interconnect on the chip. Hopefully not but it is easy to do. Thats why getting an eeprom chip is recommended, then you can afford to damage the original getting it off. put a socket on the memal and dont need to apply any heat to the new one to program and plug it in. All the heat is only on the socket which is more tollerant. If you find its faulty i'd recommend that.

[Asho88]

I didn’t make it is a stock chip and have the same thing with the stock VN chip. I brought the adaptor. When I flip it the other way it reads something but it’s upside down? I’m wondering if my adapter is dodgy they’re both blank I believe as I’ve had them under the UV light

[Charlescrown]

That red pin 7 is indicating a problem.
From AI
The programmer performs an electronic check on each pin before reading or writing to ensure stable electrical contact. A red pin means the programmer cannot properly communicate with that specific leg of the chip.

[vlad01]

I thought the red pin just meant pin 1? I'm sure my programmer showed the same.

[antus]

Yeah I thought the same. You can test the adapter with a multimter, put it on the beeper continuity mode with the memcal and the adapter and check continuity from the first pin on the chip, to the pin it connects to where it goes in to the programmer, it should beep. Then move one of the probes to the next pin over, it should not beep (if it does, there is a short). Then move the other of the probe from the first pin so they're both on the second. should beep again. Repeat around the chip to prove all of them are connecting there where they should and not to the pin next to them. If you have an adapter and have not soldered them, then problem is not likely to be heat.

I have a feeling I did this once 20 years ago and I was not getting a chip ID from the factory memcal. I didn't want to say it because I am not sure of it, but it is possible that the factory chips read FF FF. And if so you're back to power problems.
If you have a chip you have not erased, try and read it. That'll prove if everything else is working without requiring additional programming power.

[Asho88]

Ok that makes sense I don’t think it’s a power issue as when I try to write I plug the programmer straight into the wall and get no change. The red pin seems like it could be the cause. I don’t have an unerased chip to try erased them both I’m sure the VN read ok before I erased it so it being erased and showing FF could be normal.

[antus]

This is a screenshot from mine, without the programmer plugged in. I am 99.9% sure the red number is marking the end with the notch, or adding in this case "pin 7" in red because it moves depending on the size of the chip. I would not trust the AI on this one without some additional documentation to the contrary.

Did you try de-selecting ID Check and writing anyway?

[pman92]

I can confirm the factory UV EPROMs do infact return a chip ID.

If you're getting FFFF theres a connection problem, the chips fitted incorrectly, or the programmer or chip is faulty.

When I flip it the other way it reads something but it’s upside down?

You said if you put it in the other way you get something other than FFFF? What do you get.

I've got a list of chip ID bytes to manufacturer/part number. Found it on this forum years ago. If you give me the ID I will look it up. If it matches what it should you've probably got it fitted upside down.

[Asho88]

I did look at deselecting ID check but it wasn’t selected haven’t tried deselecting write I’ll have a look tomorrow. As for what it was showing I can remember but I did try to find it on the list but it wasn’t listed something starting with Z. Also as advised above the eprom has a notch to indicate which way it should go. Another question if I use the memcal adapter would that read my Nvram to save pulling it apart and risking breaking pins?