Citation de: Tibal le Dimanche 22 Février 2026, 13:09:23 PMHi,
I don't think you can rely on the Er22 info as your display is messy. You should start by testing/replacing all your 245 and 238 chips.

Thanks for fast reply, I will try that 😊👍

Hi Tibal

Have you seen this error before?

When I power it up, I do not get any segments on led2
But led3 is powering up, missinig a segment and shows 22 at the end.

What I have done so far
Swaped the borads with a working one - the error follows the board
Swaped GAL16V8 with a working one - the error follows the board

I have removed IC26 - and tested it, it where bad - so I have put in a new good 74HC373, but it is still the same error.

What to you think that causes the missing segment display?

A small video of the error here:

Hello

I have fixed ER02 on my board.
You just need to change IC9, its a TC55257DFI-70L - I orderd my new ram chips at aliexpress.

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

Hi Tibal

Thanks for your fast reply 
I will do as you mention, and let you know my results

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

Hi

Oh GREAT to hear that it where the issue 

I hope that you find a motor control board 

Kind regards
Per

Hi

I had the same issue, it where R1 and R2 that where bad.
As I recall I where unable to read the resistor fault with my multimeter, R1 and R2 failed only under load.
When I replaced them I used 1.2ohm 10W resistors (orginal it where 5W)

Hi

Just a small update to the repair log, there is a typo R24 is a 2.2ohm NOT a 220 ohm

https://www.dropbox.com/scl/fi/jdwr58zhg2tofkmensh2q/Nomenclature.ods?dl=0&rlkey=tm49vx0ax3kz10vesr5eg5ngx

Hi

If someone needs the eprom code for the eprom that is located on the motor driver board.
Then I have made a dump of my eprom

https://www.dropbox.com/s/87oitu23utdpemj/Sega-gloc-motor-eprom-tms27c256.zip?dl=0

It need to be burned on a 27C256 eprom.

Kind regards
Per

Hi

Super that the G-loc is back to life
I am glad that my L2 transformers worked. 

Also great with all the fine detail in the restoring process, that might be handy to know someday 

Kind regards
Per

Hi corner-tech

Some new status?   
Are the g loc up and running ?

There is two MK48Z02B15 cmos/batterys who stores informarion.

Expected lifespan 7 years. I have orderd some new here

DKK 176.00 | Free shipping 5pcs/lot MK48Z02B-15 MK48Z02B-12 48Z02B-20 DIP-24 CMOS 2K x 8 XEROPOWER SRAM MK48Z02B15 Goodquality
https://s.click.aliexpress.com/e/uxMSde0

Another thing - after i have reset all the options in the menus i do not longer get the ADSP error at startup?!?!?
https://www.youtube.com/watch?v=uAChM4-dc2s

So definitely I need to fix red color now 

Well some status - it seems that i can test the ADSP board in the test menu, so i have tested it - but impossible to see anything without the red color.


So i think that i need to fix the red now

Hi

Thanks - I hope that i can find out why the ADSP board is not working.

My best guess at this time is to change the caps at the  APU PCB - it gives the main PCB its +15V, -21V.
I do not know if the fault is at main pcb or the ADSP pcb.. but i am thinking that it is the adsp board, because of the missing led's

As I could tell the caps i changed at the three "game boards" where the original ones from 1989 - so It might be a good idea to change all caps on the other boards too

I have some more Documentation here if you can use it

Initervideo chassis manual: https://www.dropbox.com/s/kwo09b1czykv5i1/intervideo_vp_series.pdf?dl=0

Operators manual for the game: https://www.dropbox.com/s/divndktf7qchn6u/Hard%20drivin%20operator%20manual.pdf?dl=0