Je pense que c'est une coquille et qu'il a voulu écrire the Coin Door may be shutthe Coin Door may be shot
C'est à dire "Si la porte du monnayeur est fermée" on a MEM. PROT. FAILURE.
Porte ouverte je n'ai plus de MEM. PROT. FAILURE donc c'est OK.
----------------------------------------------------------------------------------------------------------
Pour ma carte afficheur gauche je vais essayer de tester les UDN7180 hors tension:
http://pinwiki.com/wiki/index.php?title=Williams_System_9_-_11
Testing the UDN Chips
If the display fuse is blowing, you should check the display board for shorts before connecting a new or rebuilt power supply to the display board, as a shorted display or chip can damage a good power supply. Remove the display board from the system. The display characters are driven by the two types of UDN chips, the UDN7180 & UDN6118 (or UDN6184). Locate these chips (there are several) on the board and test them with your DMM set to diode check. Clip your + (RED) lead to the ground trace of the board. Probe the UDN chips as shown in the diagram. If any shorts are read in the tested pins, the display should not be connected to the power supply until the shorts are corrected.
UDNReading.png

Qu'en pensez-vous?Shorts Are Found in UDN Chip Test
If a short reading is found in the tested pins (don't test the pins labeled 'dont care'), the UDN chip should carefully be desoldered and removed from the board. Take care to preserve this chip, as they are nearly impossible to find and expensive to replace. Now install an IC socket in its place. Repeat the test with no chip installed. If the short is gone, then the UDN chip needs to be replaced. If the short remains, then the display glass needs to be replaced.
Displays Test With no Shorts
Once the displays are tested and shorts are eliminated, we can proceed with the HV section repair.
