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Réparation Driveboard SEGA Model 3 - Tuto & Repair Logs

Démarré par Tibal, Lundi 25 Septembre 2023, 22:43:21 PM

galaganz

i try flashing the old ones  :-X

but no change ill order some gal's

or can i send to you to fix??


njz3

Can you show us (photos) which boards you are refering to?
Where is the GAL placed in this board? What are the symptoms of the board.

galaganz

thanks for the reply
ok so I powered up the 838-11967 (lemans 24 twin) using power from the PC +5v red to Sega yellow cables and black to Sega white
I could see the numbers going up and down as I moved the wheel but 10mins later it stop, and I only could see UUUU on the display reboot and same error.
so I swap over the the pcb from the left car and the the display just had blank but the "." was flashing
 
so i read this topic and order some gals from https://fr.rs-online.com/web/p/spld/1278205

programmed them and now the displays are blank
and checked the 27c512 all ok




will the bottom pcb power up without the top pcb and what does the display show??
that way I can oscilloscope it?? unless is a ram fault :( 


njz3

This topic was about another model 3 driveboard, which is not the same as yours.
I am not sure the GAL has the same number as the 315-6030 we dumped, so might have used a wrong file if you used the one from our dump.
Can you tell us what numbers are printed on your GAL?

I remembered to have such a broken board on my first lemans twin, and the issue was actually due to a blown signal diode, not something related to the GAL.


perjmolsen

Hello Tibal

I have found your great repair guide - I have a driveboard in my Scud race twin that need som love.

My issue is that durring boot if the game the wheel tries to turn, but slams to the right and does not center.
The games playes as normal but witout force feed back.

I have swaped the driveboard between the two cabinets, and the problem follows the drive board.

If I look at the driveboard segments, only the two of the four lights up. ?

The two segments that lights up displays 22.

So my plan is to follow your guide and change
1. change the four 74HC373 - and test the board
2. change two 74HC244 - and test the board
3. change the one 74HC139

Do you agree in my plan, or have some great tips (I do not have an IC tester - so I just have orderd some new IC's)

Note For a year ago I repaired the same drive borad it had er02 - then I replaced IC9 and the board played fine)

Here is a video of the driveboard booting https://youtube.com/shorts/tqnB6d_HC44

Thanks that you share your great work!

Kind regards
Per from Denmark
Kind regards
Per

Tibal

#87
Hi Per,

Your plan looks good.
If you don't have all 4 displays working, also check case 2 and 3 of the tutorial.

My advice, for time efficiency, is to desolder all the ICs you mention, test them, solder/replace if necessary, then test the board.

perjmolsen

Hi Tibal

Thanks for your fast reply  ^-^
I will do as you mention, and let you know my results
Kind regards
Per

perjmolsen

Hi Tibal

Just a small update - I have swaped GAL16V8 (IC4) between the good and the bad driver board, it id not make any diffrence at all. still only the one segment lights up, and after a while it displayes 22.
I also noticed when the steering test run's the wheel goes from left to right and center - then slams hard right and its hard ti turn back to center.

So I am waiting for the is's in my last post then I will change them. Whish me luck :)
Ill keep you updated.

Kind regards
Per Olsen
Kind regards
Per