Hey Guys,

Years back i got donated this Raven Pinball, i had a Dr. Who and a Fishtales, so hey you wanna pick up this pinball.... Yeah sure...
It has been sitting in storage for years, because it just was dead ( only some lights on the playfield went on ) and did not had time for spending after what i did:

The pinball was located in a dutch café, they did not find a better solution to fix some blown fuses with a silver wrapping paper around the fuses.
The MPU seemed to been suffering by leaking battery's so this board seems to be repaired with a memory capacitor. It seems to be done dodgy but i probably will take some pics of it later on.

So, i replaced all fuses with brand new ones, they do not blow when power on the system now.
I replaced the big capacitor on the bottom.
Still have to do the ground mod on the bottom.

Now i still get the same problems, the game does not come up, no display, the backbox looks dead, no red light on the audio board.
However if i remove the MPU, the light on the audio board does come on.

I measured the +5V , it has 5.02 V on the psu, but i did not service it yet.

I read a lot on pinwiki about the common problems, but this one just seems dead.
As i do not want to afford to just buy a new MPU, i would like to service/fix it.

I have a regular multimeter and i have a bench power supply.

Also the motor of the helicopter sometimes comes on, if it does than it spins constantly.

Can somebody help me to start with the most common thing, what do i need to measure to be sure it is not a stupid fault somewhere.
I just want to start at the beginning, wich you guys probably will say is the ground

If so, i will start there, but my guess is that it should start more with flaky ground... then just be totally dead.

Thanks in advance, any help is highly appreciated.

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Thanks for the comments.

I added pictures, first of all, I did not solder this ... This is a terrible job done... I am thinking about redoing this..
However, i am concerned on the back, there is an island of solder connecting a bunch of resistors together, can someone confirm this is normal ?
3rd picture from above, next to letter ''C'' .

Appreciate the time for answering guys !

I have the schematics printed out as manual.
However, i have no electronic background whatsoever, however i am very eager to learn it... But schematics reading is like taking a book written in chinese and you would say, this is the story about hanzel and gretel

I have been measuring the chips on the MPU, the most of them read 4.7 V, but this should be 5V right ?

At the picture you see that the chip above reads out 0.0V so either it is busted or it's because of the bad repair job ?
That is what i have to find out.

I pressed on the piggyback board, it did not change anything...
I will look around for the piggy deux, allthough it would be wasting money if this is not the problem, right ?

Check the picture.80b voltages (resized).jpg

Guys,

Happy new year to everybody, best wishes for 2020 !!!

Now, when i get done after doing the ground mod in the bottom, and wating for a new pot for the psu.
Wich reading should i get on the most chips , now i have 4.7 V but should it be a sturdy 5V ?

Mind, i did measure the capacitor directly below J1 connector and it has a proper 5V.

Just curious wich volts i have to have on the parts on the board, can't find it on internet yet.

Also, is there a possibility to see if the CPU is blown? Wich reading should i have there... For now it looks pretty dead...