4 slot neo geo repair

[Retroman839]

Repaired the bad traces
And now get


But now I’m stuck at



I have now left all the contacts
Connections with deoxit on ..
Cleaned the pcb up just a quick go over
Will try again tomo after cleaning all the cartridge slots etc ..

any advice welcome ?
I only took psu up to 5.18 v I don’t think it’s a voltage thing could it just be bad dirty / oxadized contacts ?

 

[jerryspaghetti]

Dunno if it matters too much to you but I think you can sometimes bypass those issues with a Unibios and booting into AES mode.

 

[Retroman839]

Dunno if it matters too much to you but I think you can sometimes bypass those issues with a Unibios and booting into AES mode.

Cheers Jerry ,,, I’m using the uni 4 bios

 

[jerryspaghetti]

If you hold down the 4 buttons do you get an option to boot to AES?

 

[Retroman839]

If you hold down the 4 buttons do you get an option to boot to AES?

I will try that and report back .

I went into the Controlls options
And I’m only getting ABC .. no D ..

But I can try with a aes stick on the controller inputs ..

So yeh I can toggle through the Callander etc .. / screen /sound test etc..

 

[Retroman839]

Diag chip passes all tests ..
I was going to try putting the dips into ram test next

 

[Retroman839]

 

[Retroman839]

Diffrent 4 slot same symptom

 

[Retroman839]

This one now works 🤪

I’m starting to think as this one is smaller 4 slot type it’s getting 5.2v
From my psu ..

The other knocks the psu back to 4.8 is my psu maxed out ..
Could it be a power thing

 

[Retroman839]

If you hold down the 4 buttons do you get an option to boot to AES?

All 4 buttons just resets back to cross hatch ..
So it just don’t seem to be talking to top pcb

 

[Retroman839]

Do all 4 slots need the link power cable ?

 

[Retroman839]

I got two mvH mv4.
Same model 1 with power connector

And 1 bottom only board without it ?



Do I need that to power the top pcb ?

I have meterd the side 32 pin inter connectors no voltage so my top pcb im saying needs that voltage it ain’t getting and that why my board ain’t booting into games ?

 

[Joboopoot]

What's the rating of your power supply? As fully loaded with carts the mv4 can pull 6 amps your current might not be meeting demand. Also don't go higher than 5.2 volts, as pretty sure the TTL chips have a max of 5.25 volts.

 

[Retroman839]

What's the rating of your power supply? As fully loaded with carts the mv4 can pull 6 amps your current might not be meeting demand. Also don't go higher than 5.2 volts, as pretty sure the TTL chips have a max of 5.25 volts.

Not gone over 5.2v
I really want to find the issue …
I’m thinking it isn’t getting voltage to the top board :.
I need to find out where all the voltage pins are on the 32 pin connectors ?
Test for correct voltages on top pcb
This is my next idea