SOLVED: Another Tempest upside down and mirrored but not the usual suspects.

texasmame

Well-known member
Joined
Feb 21, 2011
Messages
3,777
Reaction score
421
Location
Plano, Texas
SOLVED: This was a bad LF13201 @ E11. It's only supposed to control the Y output, so not sure why I was getting mirrored and flipped from this one chip, but I was. Thanks for the help, all!


Tempest is displaying upside down and mirrored. Self-test shows no issues. Player 1 and Player 2 are both inverted and mirrored.


I've ruled out the monitor, edge connector, interconnect cable, interconnect headers (desoldered and reflowed), entire AUX board, video EPROMs, CPU and voltages with the help of two other known working boardsets. I've not done the program EPROMS as no research shows it could be them.

It looks like the 04 at J11 on the main board would logically be an issue as it seems to be a component both the X and Y have in common. Logic probe shows the same inputs and outputs for J11 on the faulty main board and the known good main board. Same results for the 174 at N9, which also has some video inversion responsibilities for both axises.

I've not located any other components that both X and Y have in common.

At this point, I'm at a loss.

Help!
 

Attachments

  • 20250704_132147.jpg
    20250704_132147.jpg
    393.5 KB · Views: 16
  • 20250704_132155.jpg
    20250704_132155.jpg
    336.2 KB · Views: 16
Last edited:
Confirm Pin C "AND" pin10 of the POKEY is high (+5V).
Pin C on the Aux PCB's edge connector, correct, not the interconnect cable (those seem numbered, not lettered).

EDIT: If so, yes; C and pin 10 on the B/C POKEY are both solid high.
 
Last edited:
YINV controls a LF13201 analog switch. Those go bad all the time. Check "S" pin signal and the switch.
Maybe also J11 LS04 inverter as it is common to XINV and YINV.

For fun, you could always play a 2 player cocktail game (by shorting C to GND) and see what happens. :)🙃
 
YINV controls a LF13201 analog switch. Those go bad all the time. Check "S" pin signal and the switch.
Maybe also J11 LS04 inverter as it is common to XINV and YINV.
J11 checked already - see initial post.

Pin 9 on J11 (the "S" pin signal) is high.

EDIT: Shorting C to ground on a 2 player "cocktail" game does nothing for either player screen.
 
Try a new "known good" POKEY in B/C2. Make sure the socket is good. :unsure:
(TEST would not confirm this feature works or not).

Seems you have verified the cabinet wiring and monitor are good with other known logic boardset.
So, really need to validate if the bad boardset is due to the AVG board or the AUX/Mathbox board.
Swapping good with bad should confirm which is the problem. Then move on from there.
 
Last edited:
Try a new "known good" POKEY in B/C2. Make sure the socket is good. :unsure:
(TEST would not confirm this feature works or not).

Seems you have verified the cabinet wiring and monitor are good with other known logic boardset.
So, really need to validate if the bad boardset is due to the AVG board or the AUX/Mathbox board.
Swapping good with bad should confirm which is the problem. Then move on from there.

Aux board known good - this problem is on the main board itself.
 
Back
Top Bottom