| Electronics > Repair |
| Weller WMD-3 M27C256B dump needed |
| (1/6) > >> |
| Hooligan:
Hi, trying to repair the old Weller WMD-3 soldering station with MCU SAB80C535N and ROM M27C256B on board. Station has no indication at all. Finally found that ROM changes some bytes inside it every time it powers on, so the data is corrupted. Could someone help me with the M27C256B dump from a working unit? |
| wraper:
Try reading it multiple times with different VCC and IC temperature. There is a chance you can read it successfully. |
| fzabkar:
Can you upload one of your bad dumps? Perhaps you could narrow down the problem to a weak data bit, in which case you could buffer it with a comparator. |
| Hooligan:
Thanks for taking part guys, will try to play with VCC and temperature. Here are few dumps with some different bytes in it. |
| fzabkar:
ISTM that bits are being dropped rather than being set. Therefore I'm wondering if the solution would be to simply perform a bitwise OR on the contents of all the dumps. I have already written a command line tool to do this. http://www.users.on.net/~fzabkar/FreeBasic_W32/Utils/filmerge.exe http://www.users.on.net/~fzabkar/FreeBasic_W32/Utils/filmerge.bas This would be my BATch file: filmerge M27C256B-v1.BIN M27C256B-v2.BIN temp1 filmerge temp1 M27C256B-v3.BIN temp2 filmerge temp2 M27C256B-v4.BIN temp1 filmerge temp1 M27C256B-v5.BIN temp2 filmerge temp2 M27C256B-v6.BIN ROM.bin |
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