I replaced U49 and U50 on Cyclone. Restarted the pin and everything worked. After a few minutes the Diagnostic LED went out and now nothing. Where should I start looking for a problem?
I replaced U49 and U50 on Cyclone. Restarted the pin and everything worked. After a few minutes the Diagnostic LED went out and now nothing. Where should I start looking for a problem?
Quoted from Kickout:I replaced U49 and U50 on Cyclone. Restarted the pin and everything worked. After a few minutes the Diagnostic LED went out and now nothing. Where should I start looking for a problem?
Is the +5VDC LED and Blanking LED on solid?
When you turn the game on while watching the diagnostic LED, does the LED blink even once, or is it permanently out and never comes on - ever?
If the game goes to attract mode, the LED itself could have failed...I assume your game probably isn't booting to attract mode at all.
First verify correct power:
TP1 = +5 volts on the power supply board.
TP2 = ground on the power supply board.
TP3 = +12 volts on the power supply board.
TP4 = -12 volts on the power supply board.
Then begin to work through the list on the repair pages ( http://techniek.flipperwinkel.nl/wms11/index2.htm#dead )
Check Eeproms U26 U27 (game code)
Check RAM U25
Check clock U15 pin 39
etc...
Wayout440
Quoted from wayout440:First verify correct power:
TP1 = +5 volts on the power supply board. OK
TP2 = ground on the power supply board. OK
TP3 = +12 volts on the power supply board. OK
TP4 = -12 volts on the power supply board. OK
Then begin to work through the list on the repair pages ( http://techniek.flipperwinkel.nl/wms11/index2.htm#dead ) U51 Pins 8 and 9 show zero ohms.Check Eeproms U26 U27 (game code) OK
Check RAM U25 Not checked yet
Check clock U15 pin 39. Not checked yet
Ok, I am not sure why you are taking resistance measurements off the PIA. Typically, I'd be taking a signal measurement (DC Volts, Logic probe, or oscilloscope)
Backing up a bit, I neglected to ask what was the originating symptom, and why did you replace U49 and U50 in the first place?
Per the repair guide:
Check the 6821 PIA Chips.
Now check the six 40 pin 6821 PIA chips at U10, U38, U41, U42, U51, U54. The easiest way to do this is to remove the PIA chips (with the game off), one at a time, and put them in a working CPU board (in the same chip position). This way you can see if putting in the questionable PIA chip causes the otherwise working board to fail.
If you don't have a working CPU board to use as a text fixture, you can also test these chips with your DMM. With the game off, set your DMM to the "diode" setting, and put the red lead on ground (pin 1). Then put the black lead on pins 2-9 (PA0-PA7) and pins 10-17 (PB0-PB7), one by one. You should get a reading between .4 and .6 volts. If you get a short (zero) reading, replace that PIA. Note it's best to perform this test with the chip removed from the CPU board.
Replaced the U50 because it overheated
Quoted from Kickout:If you get a short (zero) reading, replace that PIA. Note it's best to perform this test with the chip removed from the CPU board.
Replaced the U50 because it overheated
So wiith the results of U51 pins 8 & 9 I assume you plan on replacing it as well.
Sounds like a dog with a few problems. Was the game working up until U50 overheated, or did this game never work since you aquired it?
When I got it was not working. Have put a lot of work into it. Had it working for a while then U50 went bad, replaced that work again now the two LEDS come on, Diagnostic led not coming on now, so I have nothing working.
Looking at the Schematic for this game, if I am reading them correctly U51 pin 8, 9 go to the Diagnostic LED. Is this correct?
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