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MVS 4 Slot issue

MegaShock-76

MegaShock-76

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As you guys can see pictured, I am having some sort of sync issues with this 4 slot mobo, which started yesterday. Below is what I have done:

Tested and adjusted PSU for correct voltage
Adjusted H/V Hold
Cleaned cart slots with Isopropyl Alcohol
Cleaned cart slots with Deoxyt
Took mobo apart, cleaned connectors and reseated everything
Checked for bulging caps, none seen leaking or bulging
Battery was replaced
Mobo is running on Unibios, I do not have the original bios to test with
Tested mobo on an SG and another cab and it continues to behave this way
Tested another PCB on Hyper Neo cab and it works great
The MOBO behaves this way even on test menu
Carts are all Cleaned and working.

I am not sure what could be going on here. Any suggestions would be appreciated.

Thank you.
 

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Was continuity tested from sync pin to monitor? Did you clean the edge connector as well on the mobo?
 
XianXi said:
Was continuity tested from sync pin to monitor? Did you clean the edge connector as well on the mobo?
Click to expand...
Yes, the edge connector has been cleaned. Yesterday, I turned it on and the picture came up but once I turned it back off then on, it started to behave the same. Not sure how to go about checking continuity from sync pin to monitor.
 
MegaShock-76 said:
Yes, the edge connector has been cleaned. Yesterday, I turned it on and the picture came up but once I turned it back off then on, it started to behave the same. Not sure how to go about checking continuity from sync pin to monitor.
Click to expand...
Checking continuity between sync and monitor by finding pin P on the jamma harness (13th pin along on the solder side) then going back to the corresponding trace on the board and checking using a multimeter in continuity mode that you have a connection between the trace and the jamma harness and then the trace and the corresponding white wire at the monitor plug.
 
I am following up to close the loop on this issue. Corrosion from previous cap leaks caused the issue. The person who did the cap kit, did not properly clean the residue from the leak. This is what I was advised by the tech.

The 4 slot is now working. Thanks to all who chimed in with suggestions.
 
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