Could this possibly be a fake EPROM? - Page 1
Forum section: electronics / general

author: SilverSolder
author_rank: Super Contributor
timestamp: February 11, 2021, 02:56:00 am
content: Not saying it is fake, but... there are certain, ahem, indications... that this may be the case?

author: wraper
author_rank: Unknown
timestamp: February 11, 2021, 03:16:10 am
content: IC should be M2764A from ST, however marking is fake. Speed grade and date code cannot be trusted. Most likely pull from old equipment sold as new IC. In the past I once made 2 orders of the same EPROM from the same seller with 1 week difference. First batch was fine, second batch was very old 21V EPROM from AMD instead of 12.5V from ST as I figured out by look of silicon die. And markings were exactly the same, including date code, on all of the EPROMs, despite them bearing different dies.

author: SilverSolder
author_rank: Super Contributor
timestamp: February 11, 2021, 03:23:49 am
content: I hadn't heard of the country of origin before....

author: Cyberdragon
author_rank: Super Contributor
timestamp: February 13, 2021, 06:22:23 am
content: Quote from: SilverSolder on February 11, 2021, 03:23:49 amIt's the country where the pope goes to sing.

author: VK3DRB
author_rank: Super Contributor
timestamp: February 24, 2021, 12:16:48 pm
content: To Get Rich Is Glorious exposed as a mixture of stupidity and greed.

author: Bud
author_rank: Super Contributor
timestamp: March 03, 2021, 06:09:00 am
content: Did you try to acetone it to see if the original marking comes visible?

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 03, 2021, 06:40:25 am
content: Yeah, see if it's painted, should be bare ceramic. I've heard of the re-marked chips but ceramic eproms is another level, who do they think they're fooling?

author: james_s
author_rank: Super Contributor
timestamp: March 03, 2021, 07:11:09 am
content: It's been repainted and re-marked. It's probably a real EPROM but it's most likely a used pull. Wish they'd just sell them as such, I'm perfectly willing to buy used pulls.

author: wraper
author_rank: Unknown
timestamp: March 03, 2021, 10:07:20 am
content: Quote from: BrokenYugo on March 03, 2021, 06:40:25 amWhat another level? It's easiest to do with old EPROM like this. Remove old paint marking with solvent and apply new.QuoteThey are fooling clueless fools of which there are plenty.

author: SilverSolder
author_rank: Super Contributor
timestamp: March 03, 2021, 02:28:06 pm
content: I don't actually have the item, that's what it looked like in the listing!

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 03, 2021, 04:23:28 pm
content: Quote from: wraper on March 03, 2021, 10:07:20 amI'm under the impression UV EPROMs are always in a ceramic case with etched markings to accommodate the erase window and survive the heavy UV exposure in the eraser. They're usually more of a dark brown/purple color too. So painting one black as is usual in the fake chip scam is kinda glaring here, nevermind that they misspelled "Singapore".

author: james_s
author_rank: Super Contributor
timestamp: March 03, 2021, 08:39:47 pm
content: Quote from: BrokenYugo on March 03, 2021, 04:23:28 pmI have a few that have been painted. They use a sort of dark brown that looks similar to the ceramic color.

author: wraper
author_rank: Unknown
timestamp: March 03, 2021, 08:48:41 pm
content: Quote from: BrokenYugo on March 03, 2021, 04:23:28 pmThere is no reason to make paint UV resistant. It's not like chip will be constantly exposed to UV. Most of them will never be exposed at all. Laser marking started to appear only in mid 90's and became prevalent in 2000's. So marking on old chips can be easily removed with solvent.QuoteNothing is painted here.