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csab00
Hungary
2 Posts |
 Posted - 07/03/2023 : 12:14:57
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I experienced a very strange thing what i cannot really explain i can just guess what is going on with my GQ-4X4
(I had also GQ-4X with the same issue)
I am using the eprom burner for programming pinball machine eproms 2716, 2732, 2764, 27128, 27256
Those eproms needed an external power supply. (I have already replaced once now i have a brand new one)
My eprom burners were working fine for a period like 1,5 year 2 year after this period the burner still writing the eproms the checking is fine from my pc but does not work in the pinball board/computer anymore.
This is the point why the situation is hard to understand.
Reading the eproms perfectly but when i am using them they are wrong!
I am just guessing here ...
May the old pinball processor 6800, 6802 cannot read the eproms anymore for some reason.
Different writing time, something is broken in the GQ-4X4.
But what? It has couple of ELKOS inside but i dont think they are bad.
Bad, fake eproms i dont think they can spoil the burner hardware.
The eproms are good (i know there are a lot of fake) among this old ones but
i can program the same eproms by my friend who has GQ-4X
If i buy a new GQ4x4 i am pretty sure it will be working but how long cca 1,5 year only ???
(The same has happened with my old GQ-4X)
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| Reply #1
anniel
2543 Posts |
Posted - 07/04/2023 : 05:06:15
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quote:
Originally posted by csab00
I experienced a very strange thing what i cannot really explain i can just guess what is going on with my GQ-4X4
(I had also GQ-4X with the same issue)
I am using the eprom burner for programming pinball machine eproms 2716, 2732, 2764, 27128, 27256
Those eproms needed an external power supply. (I have already replaced once now i have a brand new one)
My eprom burners were working fine for a period like 1,5 year 2 year after this period the burner still writing the eproms the checking is fine from my pc but does not work in the pinball board/computer anymore.
This is the point why the situation is hard to understand.
Reading the eproms perfectly but when i am using them they are wrong!
I am just guessing here ...
May the old pinball processor 6800, 6802 cannot read the eproms anymore for some reason.
Different writing time, something is broken in the GQ-4X4.
But what? It has couple of ELKOS inside but i dont think they are bad.
Bad, fake eproms i dont think they can spoil the burner hardware.
The eproms are good (i know there are a lot of fake) among this old ones but
i can program the same eproms by my friend who has GQ-4X
If i buy a new GQ4x4 i am pretty sure it will be working but how long cca 1,5 year only ???
(The same has happened with my old GQ-4X)
Voltage tests passes? |
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| Reply #2
csab00
Hungary
2 Posts |
Posted - 07/05/2023 : 04:32:14
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Please remove any chip from the ZIF socket!
*****************************
* Testing VCC Without Load *
*****************************
VCC 3.6V test passed (code:0x5e5f)+
VCC 5V test passed (code:0x8585)+
VCC 5.5V test passed (code:0x908f)+
VCC 6.2V test passed (code:0xa6a6)+
VCC 6.5V test passed (code:0xa2a2)+
*****************************
* Testing VPP Without Load *
*****************************
VPP 3.6V/5V test passed (code:0x1a1a)+
VPP 12V test passed (code:0x4f50)+
VPP 12.7V test passed (code:0x5050)+
VPP 15V test passed (code:0x6363)+
VPP 21V test passed (code:0x8686)+
VPP 25V test passed (code:0x9c9c)+
*****************************
* Test Completed *
***************************** |
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| Reply #3
ZLM
2937 Posts |
Posted - 07/13/2023 : 11:36:28
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| I think this is something to do with the EPROM VCC compatibility. The programmer has varies VCC from 5.0V to 6.2V to program EPROM chips, that gives enough flexibility to program different EPROM successfully. However, if the EPROM Vcc compatibility is not good enough, then the programmed data may not read correctly in your machine. Adjust the machine VCC may fix the issue. OR use different VCC for programming may help too. |
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| Reply #4
ZLM
2937 Posts |
Posted - 07/13/2023 : 11:44:46
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Increase the programmer VPP may reduce the marginal bytes in EPROM, so that to get better compatibility in different system.
For the GQ-4x4, change the R28 (2K) resistor to 1.8K or 1.6K will increase the 25V VPP 5-6%. That will help 25V VPP EPROM compatibility. Like 2716, 2732, 2532 etc. |
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| Reply #5
EmfDev
2 Posts |
Posted - 07/13/2023 : 12:49:44
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| that's great! thank you for your hard work. |
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GQ-4X4 broken after cca 1,5 year
