Troubleshooting a MV-1FZ with the infamous "Z80 ERROR"
- Thread starter hkz
- Start date
Is 4990CLK from NEO-F0 also connected? DIN+CLK+STB must all be good for it to receive any command. If those 3 pins, the crystal and power are all good then TP should be pulsing . If not then the 4990 should be replaced since it has everything needed to output a pulse.
I checked those 3 pins, and the connection to NEO-F0 was good. I replaced the crystal too.
The only thing I did not replace (D4990 excluded) is the couple of capacitors after the crystal.
I should be able to perform further tests at the beginning of next week, hopefully :-)
Can't wait to say that the repair on these two 1FZ is finally concluded!
The only thing I did not replace (D4990 excluded) is the couple of capacitors after the crystal.
I should be able to perform further tests at the beginning of next week, hopefully :-)
Can't wait to say that the repair on these two 1FZ is finally concluded!
I tested the other speeds and the test hangs every time.
Yesterday I received the replacement D4990A, and after soldering this one to the board, the problem seems to have disappeared!
So, it seems it was a dead clock chip: dead clock, dead smd Z80, dead YM2610 (not to mention the broken traces)... This couple of 1FZ is jinxed :P (BTW, just to be sure I checked the outputs of my PSU without load and under load: 5v and 12v clean. No spikes, no overvoltage).
I'll try to run a few tests with the diagnostic bios this afternoon or tomorrow!
Now, the last problem: one of the two 1FZ has the cart riser with a missing pin in a connector. Any ideas on where I can buy another connector (or alternatively, how to build a replacement pin?)
Yesterday I received the replacement D4990A, and after soldering this one to the board, the problem seems to have disappeared!
So, it seems it was a dead clock chip: dead clock, dead smd Z80, dead YM2610 (not to mention the broken traces)... This couple of 1FZ is jinxed :P (BTW, just to be sure I checked the outputs of my PSU without load and under load: 5v and 12v clean. No spikes, no overvoltage).
I'll try to run a few tests with the diagnostic bios this afternoon or tomorrow!
Now, the last problem: one of the two 1FZ has the cart riser with a missing pin in a connector. Any ideas on where I can buy another connector (or alternatively, how to build a replacement pin?)
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I assume the cart connector has missing pin?
So. if i had this problem.. I think many of the edge pins are GND (two top, two bottom)..
If it is just a single pin, i would get a pair of small tweezers, then heat up & extract one of the pins on the edge.
Re-insert in place of the broken one..
Also, check here, there is many NC pins on the prog connector.. I think you can borrow from there..
http://wiki.neogeodev.org/index.php?title=MVS_cartridge_pinout
So. if i had this problem.. I think many of the edge pins are GND (two top, two bottom)..
If it is just a single pin, i would get a pair of small tweezers, then heat up & extract one of the pins on the edge.
Re-insert in place of the broken one..
Also, check here, there is many NC pins on the prog connector.. I think you can borrow from there..
http://wiki.neogeodev.org/index.php?title=MVS_cartridge_pinout
heck here, there is many NC pins on the prog connector.. I think you can borrow from there..
http://wiki.neogeodev.org/index.php?title=MVS_cartridge_pinout
Great idea! I think I'll move one of the NCs
I bump this thread, I have a similar issue, no sound with unibios and eroor with OEM BIOS on MV2F
Z80 changed no difference.
Then I found that "start P1" didn't worked to make appear the test menu (but the Start button was OK on NEO-C1 pin).
So I changed the Neo-C1 as it manage also the SDdata.
Changed it, then menu now works, colors bars, RTC, inputs, memory detection, DIP switches all ok, but...sound still nok.
I will check the SM1 Rom and eventually flash a new one. The only thing I suspect again is either faulty Neo-D0 or still faulty NEO-C1, I dont see SDW changing but perhaps it's normal.
Z80 changed no difference.
Then I found that "start P1" didn't worked to make appear the test menu (but the Start button was OK on NEO-C1 pin).
So I changed the Neo-C1 as it manage also the SDdata.
Changed it, then menu now works, colors bars, RTC, inputs, memory detection, DIP switches all ok, but...sound still nok.
I will check the SM1 Rom and eventually flash a new one. The only thing I suspect again is either faulty Neo-D0 or still faulty NEO-C1, I dont see SDW changing but perhaps it's normal.
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GadgetUK
Ace Ghost Pilot
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- Sep 27, 2013
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Since you already swapped out the C1 and that fixed your controller issues I presume - I would think the D0 is next in line btw. Unless you just happen to have used a C1 that has good controls and bad Z80 related side.
apparently the D0 seems out of suspicion, as the Z80 et SM1 was removed for my initial test, I could check and compare it to the schematic of the wiki.
I discussed with Furrtek and if SDW doesn't output from NEO-C1, it's more related as you wrote, to the Z80 side which is damaged.
I discussed with Furrtek and if SDW doesn't output from NEO-C1, it's more related as you wrote, to the Z80 side which is damaged.