Mv-1fz graphics fault
- Thread starter msiggy
- Start date
chris1
POCKETBIKE NUT,
- Joined
- Oct 18, 2002
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- 10,830
msiggy said:
First off..
Is this being used in a cab or...?
What Bios chip does it have installed?
Does this happen with all MVS carts/games..?
What game or games does this happen with?
Use the cleaning methods below..
http://www.hardmvs.com/html/projects.htm
MV-1FZ PCB
http://www.hardmvs.com/html/MV-1FZ.htm
Could be a power supply issue..
Hi,at the moment it is on my bench the power all checks out ok.I do not know which bios it is using and i have cleaned the slot well.
I t happens with all my carts the same.The writing is all ok on screen,but moving objects are cut up horizontally you might get a head then bellow the other half.
I t happens with all my carts the same.The writing is all ok on screen,but moving objects are cut up horizontally you might get a head then bellow the other half.
- Joined
- Nov 12, 2002
- Posts
- 4,665
I have never seen a problem like this before. I would either say there is a problem with the GFX hardware or maybe a dirty/bad contact on the cart connection causing wrong tiles to be fetched. I would go for the latter. It seems the tile strips are repeating after 4 tiles.
Raz
Raz
ttooddddyy
PNG FTW,
- Joined
- Nov 29, 2001
- Posts
- 8,335
pm sentmsiggy said:
Well, there are no vertical lines in the sprites so that tells me all the data lines are good. The next thing you should check are the address lines on the cart connector. I posted the MVS cart port pinout many years ago but I'm not sure if it's on here anywhere. If you need it, let me know and I will send it to you (email me at jmkurtz@columbus.rr.com)
Look in the slots with a flashlight and make sure something didn't get jammed or a connector didn't bend over.
Take the cart sub board off and check all pins that connect it to the main board to make sure none were bent. If they all look good, make sure the sub board is making good contact. You can pop it on/off a couple times to help the contacts.
Check the back of the sub board for any busted solder joints or apparent broken traces.
With everything apart, hold the board(s) up to a good light source (lamp without the shade on) so that you can see through the board. This may help you find any broken traces (without resorting to continuity testing). If you don't see anything obvious, run your finger over all open areas and look close to see if there are any corrosion spots on the board. If you find anything, clean the area and check continuity of surrounding traces.
Look for bent leads on the bottom side making contact with other leads or other surface areas.
If that all looks good, it's time to get out the multimeter and do some continuity testing. You will need to focus around the LSPC2 chip as it controls the sprites. The LSPC2 has access to two different ram banks, but you generally receive a video ram error if something was wrong there, so I doubt it's the ram chips...
That pretty much leaves the traces to/from the LSPC2. The LSPC2 has a very fine pitch on the pins so you'll need a steady hand to test. If this were an AES system, I could give you some pointers on quick testing, but I've never examined a 1Z board, so I don't know the general layout of the traces.
Since the bottom of MVS boards are pretty much unprotected, I would focus some attention there as it more likely to get scratched/scuffed on the bottom, resulting in a busted trace or surface mount component.
If you just can't seem to find the problem, I can look at the board for you. I offer free evaluations and if I can't fix it, all I ask is that you cover return shipping. I also keep repairs to a minimum to make it affordable.
Jeff
Look in the slots with a flashlight and make sure something didn't get jammed or a connector didn't bend over.
Take the cart sub board off and check all pins that connect it to the main board to make sure none were bent. If they all look good, make sure the sub board is making good contact. You can pop it on/off a couple times to help the contacts.
Check the back of the sub board for any busted solder joints or apparent broken traces.
With everything apart, hold the board(s) up to a good light source (lamp without the shade on) so that you can see through the board. This may help you find any broken traces (without resorting to continuity testing). If you don't see anything obvious, run your finger over all open areas and look close to see if there are any corrosion spots on the board. If you find anything, clean the area and check continuity of surrounding traces.
Look for bent leads on the bottom side making contact with other leads or other surface areas.
If that all looks good, it's time to get out the multimeter and do some continuity testing. You will need to focus around the LSPC2 chip as it controls the sprites. The LSPC2 has access to two different ram banks, but you generally receive a video ram error if something was wrong there, so I doubt it's the ram chips...
That pretty much leaves the traces to/from the LSPC2. The LSPC2 has a very fine pitch on the pins so you'll need a steady hand to test. If this were an AES system, I could give you some pointers on quick testing, but I've never examined a 1Z board, so I don't know the general layout of the traces.
Since the bottom of MVS boards are pretty much unprotected, I would focus some attention there as it more likely to get scratched/scuffed on the bottom, resulting in a busted trace or surface mount component.
If you just can't seem to find the problem, I can look at the board for you. I offer free evaluations and if I can't fix it, all I ask is that you cover return shipping. I also keep repairs to a minimum to make it affordable.
Jeff