Elevator Action weird issue

[Layer]

I have recently tested both board sets I own : 1 board set working fine and 1 board set with light gfx glitches as spare.

About the one working fine, when I set Dip A #3 On in freeplay, coin and start buttons work but they don't if I set Dip A #3 Off to enter credits.

I have noticed there was a soldered wire between COM and P1, I have removed it but no change.

About the second board set, when I set Dip A #3 enabled or disabled, coin and start are still working.

There was no wire between COM and P1.

There is no Test mode in this game, I think the setting with the link between COM and P1 may have been saved in the EEPROM.

Is there a mean to reinitialize the EEPROM on Taito SJ games without dissoldering it ?

Layer2020-04-20 20:43:58

 

[qjuk]

It sounds to me as perhaps one or more IC’s have failed on the input circuitry and someone did a bit of hackery with the wire between P1 and COM as a workaround rather than actually fix the fault. Don’t think you can save any settings to any of the EPROMs, like you said, there’s no test mode in this game anyway.

 

[Layer]

Thanx for your point of view.

I have checked all the game eproms, especially the main program roms, they were all OK, identical to the ones from the other board set.

Do not confuse EPROMs and the EEPROM. The small 8 pins DiP EEPROM is used for the score and save of game settings.

 

[philmurr]

Other than the highscoresaves version of Elevator Action (where the settings are accessed in software), which other version of the game has an EEPROM to save the scores?

Can you post a photo of the board(s)?

 

[Layer]

Other than the highscoresaves version of Elevator Action (where the settings are accessed in software), which other version of the game has an EEPROM to save the scores?

Can you post a photo of the board(s)?

In fact it's the regular 4 PCB board set, the EEPROM is located above "BA3 09" eprom :

 

[philmurr]

In fact it's the regular 4 PCB board set, the EEPROM is located above "BA3 09" eprom :

That's a 555 timer, not an EEPROM

 

[Layer]

Possibly, I can't read the ref on mine, the stamp is scrubbed/scratched.

In this case, what could be the cause affecting coin and start buttons in standard game mode with credits enabled only ?

 

[qjuk]

That’s definitely a 555 timer. There’s no EEPROMS on Elevator Action (unless it’s some 3rd party mod).

With Dip A #3 set to normal coin play, have you tried shorting pin 8 (coin switch 1) on the “G” edge connector to Ground to see if it credits the game? Also try pin 11 (service switch) as it should also give a credit but with no crediting sound effect.

Has this just recently developed this fault and was previously working fine whilst you’ve had the board?

 

[Layer]

Previously I guess that was missing as well, as I received the game like that a bit more than 2 months ago.

 

[qjuk]

Hopefully by checking pins 8 and 11 on the connector you can eliminate any issues with your wiring harness. As you know, if there’s no credits you can’t press either player start buttons, whereas you can in free play. If either pins or both do not credit when shorted to ground then I would be looking more closely at the board stack. Check for any possible broken tracks underneath and any signs of damage to components. After that I would be getting out the schematics and logic probe.

 

[Layer]

I have taken a small wire and linked it to the ground and coin switch 1 (pin 8) on the board and on my adapter to Jamma : no result.
I have tested with service switch (pin 11) as well, and I was able to enter credits

I will check with the other boardset, pin 8 signal may work.

It seems pin 11 is not wired on my Jamma harness.

Layer2020-04-22 10:57:00

 

[Layer]

As expected, on the second board set, pin 8 signal works well with Dip A #3 On or Off.

I have to check pin 8 tracks continuity on the other one.

Layer2020-04-22 10:55:57

 

[Layer]

On the board set with coin switch 1 issue, I have done a continuity test from pin 8 to i/o resistance network, it's OK, no cut track, there is nothing abnormal. The resistance network may be tired, but coin switch 1 works when it's in freeplay mode.

Btw, not related to coin switch, I have noticed 2 signs of repair and a cut track going to pin 9.

Repair with 2 wires under D633 transistors Q1 and Q2 :

Cut track between COM and 1, going to pin 9 :

Layer2020-04-23 08:26:17

 

[qjuk]

The coin A inputs go to pins 9 and 11 on IC27 (14584) and then onto pin 13 on IC29 (7416) and pin 5 of IC28 (74LS08).

Have you got a logic probe to hand? If you touch pin 13 on IC29 it should read constantly low, when you insert a coin if should go high briefly then back to low again. Repeat this for pin 5 of IC28. This should work reading a coin input in both normal and free play settings.

 

[qjuk]

Just to add, if you are checking continuity between pin 8 on the G connector to pins 9 and 11 on IC27, it should read 100ohms.