hp28s need repair ?. Autotest fails

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hp28s need repair ?. Autotest fails

02-26-2024, 05:41 PM (This post was last modified: 02-26-2024 05:48 PM by tlfrance.)

Post: #8

tlfrance Offline

Junior Member

Posts: 7
Joined: Dec 2023

RE: hp28s need repair ?. Autotest fails

Hello,
I've repaired my 28S . I've changed the RAM 32KO chip for a new one on ebay for 7.20€

The original chip is M5M5256BFP 15L (150ns) from Mitsubishi. I've changed for a Nec D43256BGU-70LL (70ns but compatible 150ns) .

[Image: pcb.jpg]

https://ibb.co/VjkBwkJ

Autotest is pass (OK-28S), and all is working well (many lines in stack, program etc..).

Very happy.. Smile

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Messages In This Thread

hp28s need repair ?. Autotest fails - tlfrance - 01-01-2024, 03:22 PM

RE: hp28s need repair . Autotest fails - tlfrance - 02-01-2024, 05:42 PM

RE: hp28s need repair ?. Autotest fails - rprosperi - 02-01-2024, 07:41 PM

RE: hp28s need repair ?. Autotest fails - tlfrance - 02-02-2024, 09:47 AM

RE: hp28s need repair ?. Autotest fails - Steve Simpkin - 02-01-2024, 09:45 PM

RE: hp28s need repair ?. Autotest fails - Steve Simpkin - 02-01-2024, 09:49 PM

RE: hp28s need repair ?. Autotest fails - tlfrance - 02-02-2024, 09:53 AM

RE: hp28s need repair ?. Autotest fails - tlfrance - 02-26-2024 05:41 PM

RE: hp28s need repair ?. Autotest fails - vaklaff - 02-26-2024, 08:04 PM

RE: hp28s need repair ?. Autotest fails - johnb - 02-26-2024, 10:10 PM

RE: hp28s need repair ?. Autotest fails - tlfrance - 03-01-2024, 07:37 PM

RE: hp28s need repair ?. Autotest fails - Rafa - 05-22-2024, 07:00 PM

RE: hp28s need repair ?. Autotest fails - rprosperi - 05-23-2024, 11:37 AM

RE: hp28s need repair ?. Autotest fails - Rafa - 05-30-2024, 06:45 AM

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