Anyone have problems using 29F032/33s?

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Anyone have problems using 29F032/33s?
by on (#226238)
I've made a few games using these chips in the past, but I always have a REALLY bad success rate.

I've got the buyicnow adapters, and I made my own programming adapter which I know for a fact works, as I've used it in the past (and others have as well).

I'm sure it isn't the soldering, as I've gone through with a multimeter and checked all the connections and they work fine. But when I connect the breakout board to the adapter I made, and put that in the programmer (I'm using a TL866), the programmer just gives me errors when I try to do anything with it.

I chalked this up in the past to just having a bad batch of chips (I've been getting them from eBay), but I just ordered some 016's and they also don't program correctly. I'm very sure that it isn't my soldering job... just wondering if anyone else has any problems with these often? This is very frustrating because I'm trying to use them on my new SNES boards...
Re: Anyone have problems using 29F032/33s?
by on (#226289)
I've used hundreds without issue. I recall one 29016 being bad out of all of them.
I don't know your programmer, maybe it sucks. Continuity doesn't tell much about shorted pins either.
If the software that comes with your programmer tells you at which address programming fails, you can sometimes deduce which address line isn't properly connected.
Re: Anyone have problems using 29F032/33s?
by on (#226297)
I also checked for shorted pins with a meter (took a while...), that wasn't the issue either. I guess it could be the programmer, but I've programmed a ton of different EPROMs and never had trouble with them. So I'm hesitant to blame that.

I wish the errors were for specific addresses, but the errors that show up are always for the very first writing attempt. Which tells me it isn't an address pin missing.

I've also had a few work just fine, but on like the 3rd reprogram they would suddenly stop working. That's happened twice now. And I was using sockets, never had to desolder to reprogram, so unless it's just an intermittent connection that I'm not catching with the meter, it leads me to think the chip is the problem.

Maybe I just got really unlucky... I've only used a handful 032s so far. I'm going to try another 016 later. I guess you having used many without incident is good to know, I should order some more and try again. These are old chips, so I figured age could have gotten to them.
Re: Anyone have problems using 29F032/33s?
by on (#226392)
poorstudenthobbyist wrote:
Maybe I just got really unlucky... I've only used a handful 032s so far. I'm going to try another 016 later. I guess you having used many without incident is good to know, I should order some more and try again. These are old chips, so I figured age could have gotten to them.


Another possibility besides the programmer, are they all from the same supplier? It's not uncommon to find fake or remarked chips on ebay. If I saw a good enough picture of them, I could probably tell you if they're legit.

Age of the chip is almost never a problem, with a few unfortunate exceptions that are particular to one part (the SNES CPU seems to be a victim of this). I've seen an IC as old as 1967 that is still in daily use in an industrial control.
Re: Anyone have problems using 29F032/33s?
by on (#226394)
I forget where I saw this -- maybe Twitter, maybe nesdev -- but someone recently showed evidence of some vendors selling EPROMs/EEPROMs as new, which are actually quite old and used (read: likely failing and bad). In turn this drives devs crazy because they aren't sure if the chip is bad or if their programmer is freaking out. We have several posts here on this forum of people discussing/worried about the latter.
Re: Anyone have problems using 29F032/33s?
by on (#226568)
koitsu wrote:
I forget where I saw this -- maybe Twitter, maybe nesdev -- but someone recently showed evidence of some vendors selling EPROMs/EEPROMs as new, which are actually quite old and used (read: likely failing and bad). In turn this drives devs crazy because they aren't sure if the chip is bad or if their programmer is freaking out. We have several posts here on this forum of people discussing/worried about the latter.


Hey thanks a lot for this info. Maybe I should try buying some more and seeing if I have better luck this time. I was really turned off.

Out of the 016's I mentioned, only one so far was bad (out of the four I've tried so far). That's a lot easier to swallow though since those are cheaper.