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dmeB
USA
2 Posts |
 Posted - 10/20/2010 : 10:19:45
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I just bought a willem PCB5 from mcumall. I was able to read a few 27sf512 eeproms I have, as well as a 27C256.
I'm using the unit to burn eproms for a Bosch engine control unit.
At first I was having issues with the software/burner and trying to erase the 27sf512 chips. The burner is wiping data off of the chip, but it never passes a blank check. It would usually read 04 and 16 on the chip. I've confirmed the VPP is set to 15volt, and the dips are set properly. The safety jumper is in place. Still can't erase chips, or have them pass a blank check.
Now, if I set the DIPs back to the settings for 27c256 and try to read what was a good eprom, I get very strange results in the buffer, and that eprom is no longer working. If I take the chip and put it into the ECU, it no longer works. If I use a much more expensive burner/reader it shows that the data on the chip is not what it should be. Somehow corrupted.
So my question, is this a bad unit? It doesn't make sense how just reading a chip would corrupt the data on it. It also doesn't make sense that I've never been able to erase/burn an eeprom.
Some other questions-
What should the jumper that is between jumper 6/7 and the ZIF supposed to be set to? Some forum posts say this jumper should be open, is that correct?
I also found no information about the jumper right next to the LEDs. On my unit, sometimes all three LEDs are lit up, sometimes just the green/red with the yellow changing depending on the zif socket being closed, or the safety jumper being in place.
I've also noticed that I get the same weird results trying to read chips even if I read with the ZIF socket completely emtpy. It returns a bunch of 04 and 16 values.
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| Reply #1
ZLM
2945 Posts |
Posted - 10/21/2010 : 13:23:28
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Based on datasheet of 27SF512, the VPP should be 12V, not the 15V.
Read the empty socket will show 04 or 16 in buffer. That is correct.
The jumper need to set not only the DIP, but also the special chip jumpers: JP1 and JP2
The jumper beside the LED is A18 jumper. It should set to lower two pin for your case.
Other jumper see:
http://www.mcumall.com/forum/topic.asp?TOPIC_ID=106
You can search this forum for more other post regarding your questions. |
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| Reply #2
dmeB
USA
2 Posts |
Posted - 10/22/2010 : 08:50:41
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I get 04 and 16 values even with chips in the reader.
Jumper 1 and 2 are set correctly. I'll go back and verify the jumper next to the LEDs.
What is the easiest way to verify VPP using a multimeter? I've seen some posts about it using the test h/w page, but it isn't exactly clear to me how to use that page to test VPP.
What about the jumper that is close to the power jumpers? I don't have the board right in front of me, but it might be jmp7. It has a 5v6(top two pins) or 5v(lower two pins). That is VCC correct, and should be 5v?
Should the leds be VPP and power only when the board is first started and initialized by the software? If I see all three lights with no chip, should I reset the board, and send a command via the software before putting a chip in it? |
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Problem with willem PCB5
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