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G N R Data East display problem

Poibug

Poibug

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10 Years
Joined
Aug 10, 2011
Messages
3,305
Location
flintshire
So, G n R is currently fooked.Boots ok,and checked the PIA's that seem ok and it goes into attract mode with all the attract lights working.
Game won't start plus i dont have anything on the dmd.
All incoming voltages are there at the dmd,and the dmd was tried in another game ok.

I disconnected all plugs from cpu apart from power,enable and dmd ribbon but nothing.Tried same again but with TFTC cpu and display roms but still nowt thus ruling out a knackered rom.

I did fook the original display up when another problem originally appeared and I connected my spare power supply board up with voltage connector outputs to the dmd one pin out:mad:
I am guessing the display driver board is now knackered,tho not sure how unless summat travelled up to it from dmd thru the data lines?

Any ideas on what to do next?

I do have a LOTR and am trying to figure out if the dmd controller boards are compatible

data lines at ribbon connector on cpu board seem ok with the leon test eprom in

All of this stemming,originally from the bridge on the power board going tits up

Knobbed off - esp as some pinheads visiting soon:(
 
This feels like teaching my grandma to suck eggs but does it start with the CPU isolated from the DMD? That would eliminate the display driver board being the problem.
 
Looking at the keying, the way you will have offset the connector, you will have put +12v into the +5v and +68v into the 12v lines.

If you were lucky, and one of the IC's on the DMD driver shorted out and acted like a fuse for the rest of the board, else the damage could be quite extensive
 
The game can see the DMD driver board (and the game driver PCB) otherwise it will not boot. It's a feature of DE/Sega/Stern games. I've sent a PM to poibug, I suspect his PAL chips on the driver PCB are corrupted or wiped clean... :(
 
Sorry Mr Moonraker, I am absolutely certain that Data East games boot (and can be started) without the DMD driver board attached. I've done this on my test bench many times. Also just pulled the ribbon off in my Star Wars to confirm
 
Peter may be right.
Using the VERY BASIC theory
I once read that a hot chip is frequently bad so I noticed a 74LS245 chip was very hot(for a chip)so I changed it.It is now ok,tho,sadly one of the PAL chips is hot too,and I am unable to replace that,as I do not know where to get them.

On an aside note,anyone know if a Data East board can be run "on the bench?"
IE applying 5volts and then shorting out the reset pins-does that,at least show summat on the dmd?
 
Ah,just saw Lukes post.How do I do it Luke re the dmd board only-put 5 volts on then what
 
Spoken to Chris,

I don't think his cpu board has any fault, but yet they can be powered up easily on the bench with standard voltages.

The original connection of the DMD power connector incorrectly will have caused high voltage damage to the controller chips on the DMD display itself, and likely sent some high voltages back down the data cable to the DMD controller board.

U1 (74HCT240) will need replacing at the very minimum and the PAL chips are next in line, so may have also taken some damage.
 
U1 done,Pal chips next

Hope they fix it

Spirit died today,tho thankfully I had all the bits needed to fix that,man my pins are being a major PITA at the mo,they hate me.
Black Hole went on one as well two nights ago,tho again,had spares on hand to fix that,as I did the AFM strobe board that died 4 days ago.

Feeling got at!!
Wonder what will die next?Normally mine are all pretty reliable,they only seem to go wrong just before when pinheads are to visit!!
 
The joys of pinball ownership hey mate. I've got problems with my blackout. At least you've got the skills to do the repairs as opposed to farming everything out.
 
so,the main 5voltage is low but back to what its allways been, 4.82 volts .
With a loaned dmd driver board,and a TFTC display rom in I now have the display.
So picking up a dmd rom tomorrow,will see how it goes from there,and gonna borrow a power supply board for weekend too
going forward will have to RE-LOOK at low voltage-tho I did that a year ago,and after replacing regulator,caps,and repinning input ac voltage connectors,it never improved,but then gave up as it always worked(and carried on working till this initial BR 1 disaster a year later!!).

With the luck of the gods I may even have it at least playable for the weekend - allbeit with borrowed bits n that!
 
Sorry Mr Moonraker, I am absolutely certain that Data East games boot (and can be started) without the DMD driver board attached.
Click to expand...
Yup, the DMD Driver is it's own separate computer, same as the sound board, so it's not needed for the main CPU to boot.
 
i learnt during fault finding that ya can have a different cpu rom compared to the display rom and it still works.That was with data liens connected.
Found that out when after a fair bit of testing suspected the gnr rom so tried it.It worked,as it turned out the gnr display rom was corrupted somehow
 
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