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4x4
USA
11 Posts |
 Posted - 03/30/2020 : 08:30:30
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Good afternoon. I'm using a GQ-4x4 programmer with external power supply and an ADP-054 adapter to burn a few AM27C400 EPROMS. I purchased the EPROMS from a reputable dealer, and I'm able to blank check and fully read/write both 00's and FF's. It seems as though no matter what I do, the writing process refuses to pass the first line.
I've cleaned pins, reflowed solder, and passed voltage checks. I've switched USB cables, swapped EPROMS, and tried pretty much everything there is to try. All software and drivers are up to date.
I attached an image of the error message I'm receiving.
Is anyone able to chime in? Any help would be greatly appreciated.
Image Insert:
68146 bytes |
Edited by - 4x4 on 03/30/2020 14:08:09
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| Reply #1
4x4
USA
11 Posts |
Posted - 04/01/2020 : 06:03:49
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| Did I post in the wrong part of the forum? This is making me tear out the last bit of hair I have left! |
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| Reply #2
anniel
2572 Posts |
Posted - 04/01/2020 : 06:22:52
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quote:
Originally posted by 4x4
Good afternoon. I'm using a GQ-4x4 programmer with external power supply and an ADP-054 adapter to burn a few AM27C400 EPROMS. I purchased the EPROMS from a reputable dealer, and I'm able to blank check and fully read/write both 00's and FF's. It seems as though no matter what I do, the writing process refuses to pass the first line.
I've cleaned pins, reflowed solder, and passed voltage checks. I've switched USB cables, swapped EPROMS, and tried pretty much everything there is to try. All software and drivers are up to date.
I attached an image of the error message I'm receiving.
Is anyone able to chime in? Any help would be greatly appreciated.
Image Insert:
68146 bytes
Does the ID return a value consistant with the datasheet? |
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| Reply #3
anniel
2572 Posts |
Posted - 04/01/2020 : 06:23:21
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quote:
Originally posted by 4x4
Did I post in the wrong part of the forum? This is making me tear out the last bit of hair I have left!
Don't despair. |
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| Reply #4
4x4
USA
11 Posts |
Posted - 04/02/2020 : 16:44:04
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| When clicking "ID" the software brings up a "Function not supported on this device" error. I assume this is due to the adapter. |
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| Reply #5
laptech
United Kingdom
58 Posts |
Posted - 04/03/2020 : 01:42:44
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| Do not assume that the default speed setting of -2 will work. On some chips it is trial and error to see which speed setting works with the chip. It takes a long time to figure it out though. |
Laptronics UK LTd. Specialist motherboard repair. |
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| Reply #6
anniel
2572 Posts |
Posted - 04/03/2020 : 04:51:32
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quote:
Originally posted by 4x4
When clicking "ID" the software brings up a "Function not supported on this device" error. I assume this is due to the adapter.
You are right. |
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| Reply #7
anniel
2572 Posts |
Posted - 04/03/2020 : 04:51:42
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quote:
Originally posted by laptech
Do not assume that the default speed setting of -2 will work. On some chips it is trial and error to see which speed setting works with the chip. It takes a long time to figure it out though.
Some chips also need the voltages to be tweaked. |
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| Reply #8
4x4
USA
11 Posts |
Posted - 04/03/2020 : 06:37:30
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I tried all speeds, and still nothing. -2 just happened to be what I was using when I grabbed the screen. This is what I meant when I said "tried pretty much everything else there is to try", but perhaps I should have been more clear. ;)
As far as changing voltages, I took a look at the devices.txt a few days ago and adjusted it based on other people who have posted issues with AM27C400 in the past. I'm still getting the same errors. Unfortunately, all related posts usually end without much of a resolution.
I did notice however that in devices.txt there's a "RVPP" and "RVpp" on the same line. I've read that the generic flashrite programming algorithm says to verify at 5.25v, but when I change RVPP (assuming it's the same as RVpp) I receive a parse error when the GQ software boots, so I changed it back. |
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| Reply #9
anniel
2572 Posts |
Posted - 04/03/2020 : 09:07:26
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quote:
Originally posted by 4x4
I tried all speeds, and still nothing. -2 just happened to be what I was using when I grabbed the screen. This is what I meant when I said "tried pretty much everything else there is to try", but perhaps I should have been more clear. ;)
As far as changing voltages, I took a look at the devices.txt a few days ago and adjusted it based on other people who have posted issues with AM27C400 in the past. I'm still getting the same errors. Unfortunately, all related posts usually end without much of a resolution.
I did notice however that in devices.txt there's a "RVPP" and "RVpp" on the same line. I've read that the generic flashrite programming algorithm says to verify at 5.25v, but when I change RVPP (assuming it's the same as RVpp) I receive a parse error when the GQ software boots, so I changed it back.
Please post that line. |
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| Reply #10
4x4
USA
11 Posts |
Posted - 04/03/2020 : 11:24:43
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Name="AM27C400",ID="XXXX",Class="27C800",Category="EPROM",MFG="AMD",CodeSize="524288",VCC="5V",RVPP="12V",WVCC="6.5V",Adapter="ADP-054 16 BIT EPROM Adapter",RVpp="5V",Message="Put chip in 42 pin socket and bottom aligned with the socket.";
**EDITED - Sorry, posted the wrong line** |
Edited by - 4x4 on 04/03/2020 11:31:37 |
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| Reply #11
anniel
2572 Posts |
Posted - 04/03/2020 : 12:10:18
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quote:
Originally posted by 4x4
Name="AM27C400",ID="XXXX",Class="27C800",Category="EPROM",MFG="AMD",CodeSize="524288",VCC="5V",RVPP="12V",WVCC="6.5V",Adapter="ADP-054 16 BIT EPROM Adapter",RVpp="5V",Message="Put chip in 42 pin socket and bottom aligned with the socket.";
**EDITED - Sorry, posted the wrong line**
Not sure who crafted this line but it is wrong. Try this: Name="AM27C400",ID="XXXX",Class="27C800",Category="EPROM",MFG="AMD",CodeSize="524288",VCC="5V",RVPP="5V",WVCC="6.5V",Adapter="ADP-054 16 BIT EPROM Adapter",Message="Put chip in 42 pin socket and bottom aligned with the socket."; |
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| Reply #12
4x4
USA
11 Posts |
Posted - 04/03/2020 : 14:32:45
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Assuming I just copy/paste/save the devices.txt, and boot up the GQ software like normal, I'm getting the same results. Tested on all speeds.
Frustrating. |
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| Reply #13
anniel
2572 Posts |
Posted - 04/03/2020 : 15:26:48
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quote:
Originally posted by 4x4
Assuming I just copy/paste/save the devices.txt, and boot up the GQ software like normal, I'm getting the same results. Tested on all speeds.
Frustrating.
Try other voltages. |
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| Reply #14
4x4
USA
11 Posts |
Posted - 04/03/2020 : 17:09:24
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| Based on a disassembly of the software, RVPP seems to be limited to 0V,3.6V,5V,9V and 12.7V. Am I just cycling though these for RVPP or WVCC? Also, should there be a 'WVPP"? |
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| Reply #15
anniel
2572 Posts |
Posted - 04/04/2020 : 05:20:07
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quote:
Originally posted by 4x4
Based on a disassembly of the software, RVPP seems to be limited to 0V,3.6V,5V,9V and 12.7V. Am I just cycling though these for RVPP or WVCC? Also, should there be a 'WVPP"?
Mainly WVCC for a start, you are limited by the values present in the voltage diagnostic menu. |
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| Reply #16
4x4
USA
11 Posts |
Posted - 04/04/2020 : 14:19:09
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Writing worked!!! THANK YOU. I got it to work by changing the line to the following:
Name="AM27C400",ID="XXXX",Class="27C800",Category="EPROM",MFG="AMD",CodeSize="524288",VCC="5V",RVPP="5V",WVCC="5V",Adapter="ADP-054 16 BIT EPROM Adapter",Message="Put chip in 42 pin socket and bottom aligned with the socket.";
**HOWEVER** It seems as though two things are happening now:
1) The GQ program cannot successfully verify the EPROM. I'm not sure if this is a setting in the devices.txt, or if this is due to the adapter.
2) It seems as though the EPROMS I'm reading with the GQ are not working when burning back to an EPROM, despite reading 100% without error.
For instance, I was able to burn an online .bin image to EPROM and successfully use it in my machine. When I read that same working EPROM and tried to burn a new EPROM from the newly verified working EPROM, it didn't work. Also, EPROMS are in good shape and not faulty.
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| Reply #17
anniel
2572 Posts |
Posted - 04/05/2020 : 05:40:40
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quote:
Originally posted by 4x4
Writing worked!!! THANK YOU. I got it to work by changing the line to the following:
Name="AM27C400",ID="XXXX",Class="27C800",Category="EPROM",MFG="AMD",CodeSize="524288",VCC="5V",RVPP="5V",WVCC="5V",Adapter="ADP-054 16 BIT EPROM Adapter",Message="Put chip in 42 pin socket and bottom aligned with the socket.";
**HOWEVER** It seems as though two things are happening now:
1) The GQ program cannot successfully verify the EPROM. I'm not sure if this is a setting in the devices.txt, or if this is due to the adapter.
2) It seems as though the EPROMS I'm reading with the GQ are not working when burning back to an EPROM, despite reading 100% without error.
For instance, I was able to burn an online .bin image to EPROM and successfully use it in my machine. When I read that same working EPROM and tried to burn a new EPROM from the newly verified working EPROM, it didn't work. Also, EPROMS are in good shape and not faulty.
If you nudge VCC? |
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| Reply #18
4x4
USA
11 Posts |
Posted - 04/05/2020 : 08:29:59
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| Sorry, I should have mentioned - I tried 3.6, 5, 5.5, 6.2, and 6.5 for VCC and I'm still getting a "failed" message. |
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| Reply #19
4x4
USA
11 Posts |
Posted - 04/05/2020 : 11:06:08
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So I switched "VCC" to 3.6V again this morning and I'm now able to verify successfully. I'll leave it as is since it's working. Oddly enough, I'm running into another issue.
I am able to read one EPROM (let's call it EPROM #1), write it's contents to another EPROM, and successfully verify it both in the GQ software and as working in my machine, so I now have EPROM #1 and a working copy of EPROM #1. However, when I try the same for a different EPROM (let's call it EPROM #2), I cannot get the copy (of EPROM #2) to work in my machine, despite a "successful" (according to GQ software) read and verify. The EPROM isn't faulty.
Looking into this a little deeper this afternoon. Thank you again for all of your help anniel. It is very much appreciated.
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Edited by - 4x4 on 04/05/2020 11:08:03 |
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| Reply #20
anniel
2572 Posts |
Posted - 04/05/2020 : 15:30:15
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quote:
Originally posted by 4x4
Sorry, I should have mentioned - I tried 3.6, 5, 5.5, 6.2, and 6.5 for VCC and I'm still getting a "failed" message.
Ok. |
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| Reply #21
anniel
2572 Posts |
Posted - 04/05/2020 : 15:30:24
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quote:
Originally posted by 4x4
So I switched "VCC" to 3.6V again this morning and I'm now able to verify successfully. I'll leave it as is since it's working. Oddly enough, I'm running into another issue.
I am able to read one EPROM (let's call it EPROM #1), write it's contents to another EPROM, and successfully verify it both in the GQ software and as working in my machine, so I now have EPROM #1 and a working copy of EPROM #1. However, when I try the same for a different EPROM (let's call it EPROM #2), I cannot get the copy (of EPROM #2) to work in my machine, despite a "successful" (according to GQ software) read and verify. The EPROM isn't faulty.
Looking into this a little deeper this afternoon. Thank you again for all of your help anniel. It is very much appreciated.
Are all the chips from the same lot number? |
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| Reply #22
4x4
USA
11 Posts |
Posted - 04/05/2020 : 15:44:27
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| They are different lots, but the same type. |
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| Reply #23
anniel
2572 Posts |
Posted - 04/06/2020 : 05:04:33
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quote:
Originally posted by 4x4
They are different lots, but the same type.
Could you post a double-sided pictures of the chips in a row? Does the dies look the same? |
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Topic |
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AM27C400 stops writing at 0%
