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That must be the IC22 having different checksums.
Yeah that makes sense

OP, to elaborate, the IC22 contains the 'correct' values the test is looking for. If that chip has the wrong values, then test mode could show all other chips as bad.
 
so what game number is on the roms? i'll try and find the matching ic22
Well... I downloaded the exact number that was on the chip... 23511c.

I'd be happy to try someone else's 23511c as apparently the one I have isn't correct. :(
 
I also tried erasing and burning more of those "modern" m27c322 chips I got and they all still failed during the burning process. I then took the original capcom chip and erased it and try to burn it and just like the original 18 wheeler chip, it burned perfectly fine. So, the original rom chips work perfectly fine if I erase them and burn them, but the batch of 14 of the ones with the smaller window do not work at all despite the specs being the exact same. Think I'm gonna have to order more of the larger window ones from China as I can't find any stateside or in the UK or Canada.
 
Sounds like fake Eproms to me.

Good idea.
@stj @skate323k137

Chinese order of new m27c322 chips finally came in yesterday and they were the ones with the bigger window and they worked perfectly. Should I even bother sending a message to the guy I bought the other chips from to let him know they were faulty or just let it go?

Thanks again guys for all your help!
 
Glad you got some good chips. Bad components can be so frustrating; I almost soldered in 30+ capacitors (of the same value) today. Before I started I put one on the component tester and it was way off spec. Same with the next, and the next, and the next. Thankfully I had a bag of ones that were in spec. It won't help with EPROMS but a cheap component tester can save a boatload of headaches especially with eBay parts.
 
let it go, he probably just resold stuff from the shenzen market anyway.
I thought so as well, it is just with the high rating he had, I would think he would want to know to avoid an issue. I know I would want to know if chips I got were bad if I were selling them. Definitely would help to avoid altercations down the road.
 
I thought so as well, it is just with the high rating he had, I would think he would want to know to avoid an issue. I know I would want to know if chips I got were bad if I were selling them. Definitely would help to avoid altercations down the road.
That makes a lot of sense, you're a good person :)
 
Glad you got some good chips. Bad components can be so frustrating; I almost soldered in 30+ capacitors (of the same value) today. Before I started I put one on the component tester and it was way off spec. Same with the next, and the next, and the next. Thankfully I had a bag of ones that were in spec. It won't help with EPROMS but a cheap component tester can save a boatload of headaches especially with eBay parts.
Yeah I got a few of them. My biggest problem with them is that some of the cheaper ones don't have any instructions and its a trial and error when testing. Some will say capacitor one way and then the other way they say diode. lol. I'm still learning and understand that I'll always be learning. I'm just glad I got good guys like you out there willing to help us lesser beings. :D
 
Yeah I got a few of them. My biggest problem with them is that some of the cheaper ones don't have any instructions and its a trial and error when testing. Some will say capacitor one way and then the other way they say diode. lol. I'm still learning and understand that I'll always be learning. I'm just glad I got good guys like you out there willing to help us lesser beings. :D
Learning is the fun part.

Thank you for the kind words. I look up to people just the same, so to speak.
 
we could start a thread about component testers,
i upgrade them with faster crystals, better reference chips, sometimes bigger microcontrollers etc.
and i compile customised firmware for them. :)

if you use a 20MHz crystal you can test crystals & resonators upto atleast 10MHz :)
also you can build an adapter that tests opto-isolators and even gives you the transfer ratio!
 
we could start a thread about component testers,
i upgrade them with faster crystals, better reference chips, sometimes bigger microcontrollers etc.
and i compile customised firmware for them. :)

if you use a 20MHz crystal you can test crystals & resonators upto atleast 10MHz :)
also you can build an adapter that tests opto-isolators and even gives you the transfer ratio!
That would be great! I'm always testing new test equipment and finding myself disappointed that I spent money on something so crappy. lol.
 
Yeah I would love a good thread on component testers, even my cheap one (I calibrated it) saves me a lot of headaches. Would love to learn more as I assemble more advanced projects.
 
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