Neo MVH MV4 PCB won't boot...I think...

[TheChaz]

Hello Everyone,

I am new here and I was hoping someone could help point me in the right direction. I have a MVH MV4 PCB and it won't boot bast the initial screen with the weird green graphics. This board came with a machine I just purchased and I was hoping I would be able to fix it. I have removed the battery, which seemed to be fine, but I did read how they leak so, it now disconnected. There are areas on the board where it looks a bit suspect, but then again, I've seen some dirty boards fire up without issue. The cap that I'm pointing to was bad and leaked a bunch of white stuff on the board, so I replaced it. Where would be a good place to start troubleshooting if my board doesn't make it to the crosshatches? Thank you in advance!

 

[Heinz]

The first two pics are some pretty good examples of corrosion that's travelled under the solder mask. Likely this will be a lost cause.

 

[TheChaz]

Thank you for your quick response. Can you help me understand this a little better? I thought battery corrosion repairs consisted of re-routing the corroded connections. Is there an easy way to test other than conductivity testing? If I were to identify and fix the corroded connections, where would be the next place I would need to troubleshoot to ensure the pcb is booting up correctly? Again, thank you for your insight. I really enjoy fixing stuff.

 

[Heinz]

First I'd be testing continuity on all the traces around the battery area, especially the connector to the left.

Should should post a picture of the screen you get and also get a unibios and diag bios to help diagnose further.

As the 4 and 6 slot boards are multi PCB, you will want to make especially sure continuity is present between the boards at where they join together.

 

[mainman]

Ok if I understand you correctly it wont even go to croshatch

 

[theMot]

There is thousands of these things knocking around out there, just buy another one. Put this one in the trash and move on with your life.

 

[TheChaz]

There is thousands of these things knocking around out there, just buy another one. Put this one in the trash and move on with your life have another working one. I'll take any trash PCBs you may have though.

Ok if I understand you correctly it wont even go to croshatch

Yes, it doesn't make it that far and I'm not sure which part to start testing first.

 

[TheChaz]

First I'd be testing continuity on all the traces around the battery area, especially the connector to the left.

Should should post a picture of the screen you get and also get a unibios and diag bios to help diagnose further.

As the 4 and 6 slot boards are multi PCB, you will want to make especially sure continuity is present between the boards at where they join together.

Is seems that a 4 and 6 cart board doesn't need the top board for the testing I need to do. Is that true?

 

[TheChaz]

There is thousands of these things knocking around out there, just buy another one. Put this one in the trash and move on with your life.

I have another working one. I'm more interested in figuring out what went wrong with this one and how to fix it. If you aren't interested in helping that's cool. Also, if you want to send me any old PCBs that you consider trash, I'll take them all.

 

[TheChaz]

First I'd be testing continuity on all the traces around the battery area, especially the connector to the left.

Should should post a picture of the screen you get and also get a unibios and diag bios to help diagnose further.

As the 4 and 6 slot boards are multi PCB, you will want to make especially sure continuity is present between the boards at where they join together.

Thank you, I'll do some testing and post an image of the screen later today.

 

[Neo Alec]

Make sure the pause switch (dip switch 8) isn't on.

 

[TheChaz]

First I'd be testing continuity on all the traces around the battery area, especially the connector to the left.

Should should post a picture of the screen you get and also get a unibios and diag bios to help diagnose further.

As the 4 and 6 slot boards are multi PCB, you will want to make especially sure continuity is present between the boards at where they join together.

I did some continuity testing on CN10 and the whole B side is bad, except for the power and ground. There are a few on the A side that are bad as well. So, my next questions are:

1) what type/gauge of wire should I use?
2) what is the best way to manually make these connections?

B25 PRO-C0 (72) - NG
B26 PRO-C0 (74) - NG
B27 PRO-C0 (75) - NG
B28 PRO-C0 (73) - NG

Thank you again for your help!

 

[TheChaz]

Make sure the pause switch (dip switch 8) isn't on.Thank you for reminding me to check that, currently they are all off. I'll make sure again before I post the screen image at boot.

 

[Heinz]

1) Kynar!
2) with great patience and skill

 

[TheChaz]

Ok if I understand you correctly it wont even go to croshatch

Yea, so I get this screen, but that is all. On my working one, it progresses to the crosshatch. This does not. So, I am wondering what I part of the pcb I should focus on for this issue. Any insight would be appreciated.

 

[TheChaz]

1) Kynar!
2) with great patience and skill

Got #1, we will see how #2 goes. Thank you.

 

[Neo Alec]

Install the diag bios.

 

[TheChaz]

Install the diag bios.

I just ordered one.

 

[channelmaniac]

Stuck on Green has been covered here before and in my repair logs. It means the clock / calendar is not working. Look for battery damaged traces around the D4990C chip and make sure the crystal and 2 small green caps aren't roached.

 

[HeavyMachineGoob]

Stuck on Green has been covered here before and in my repair logs. It means the clock / calendar is not working. Look for battery damaged traces around the D4990C chip and make sure the crystal and 2 small green caps aren't roached.

hey ChannelManiac, are you taking JAMMA board repairs again? Or no?

 

[channelmaniac]

hey ChannelManiac, are you taking JAMMA board repairs again? Or no?

Starting back up in December. Have a few boxes to finish this weekend.