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domlouis

domlouis

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So for the first time today I plugged in my Excalibur....... and as expected that didn't go to plan.
Having made sure that all fuses were present and of the correct amp I turned it on.
For about 1 second it displayed 000000 scores on all 4 scores and no credit. Then that went off.
And it stayed off.
Playfield lights are on.
Can't start a game.
Rechecked all fuses and they are all ok still.
Turned it in and off and displays stays dead.
Opened the back box and this is what I saw - see the picture.
On the board on the left hand side there is a red diode in the middle that is unlit. Somehow I presume it should be on. Is that right?
Tomorrow I will be resetting all connectors on the boards as I believe that it is the usual fix.
Beyond that any idea on what else to try?
I have a multimeter at hand. But I am rubbish at electronics. If you make a suggestion please keep it simple.
Thanks
Dom
 

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Dom @domlouis the important boards at this point are the top two (one on the left is the sound board, one on the right is the MPU board) and the 5v regulator board which is the little one above the sound board with a heatsink on it.

The red diode on the sound board being off means it's not getting 5v and I suspect your MPU board is the same. Disconnect the top plug from the 5v regulator board and check if you're getting a stable 5v at the pins. If you are then disconnect the power connectors from both MPU and sound boards, plug the top 5v connector back in and see if you're getting 5v at the connectors :thumbs: Where in Derby are you as I might be able to get over and give you a hand?
 
Chris
You are a genius.
Did what you said and checked the voltage out of the 5v regulator board and they were all steady 5v.
Then identified the mpu board input connectors and unplugged it. Checked it was receiving 5v and it did and replugged it. Magic moment. Game come to life.
Hurrah.


More faults to fix later on but this is a gigantic step forward. Thanks.

I'll update the thread with the other faults as I come across them.
 
Magic moment. Game come to life
Click to expand...

Good news :thumbs: Might be worth giving the header pins on the MPU board a clean with a fibreglass pencil if you have one and pop the board out and check for any dry solder joints on the back of them as well.
 
After the initial success in getting the game back and running, the same problem occurred but this time resitting the connectors did not work.

Great advice from Chris about the fibreglass pencil. Bought some and gave the MPU board a good clean with the pencil and the game is back on. There is one troublesome connector but i have a plan to fix it.

Cleaning the MPU board enabled me to see the repairs that have been carried out on it, i can see at least 3...

The niggles i still have are: the jet bumper behind the ramp does not fire. I have only checked that there was no loose wires so far and there was none but i will do more tests soon.

And the sound seems incomplete. Does anyone know if there is meant to be a background music to the game? I can get the sound when hitting targets, passing switches etc, but otherwise it is very quiet...

Thanks.
 
Yes, you should have background music...I've had to re-pin many connectors on my Gotts. Often troublesome...
 
Which one arv? The one that feeds the sound board?
I still don't get a lit diode in the middle of the sound board... but I get some sounds....
 
The main one with the twisty turn pot.
 
Argh, things are getting from bad to worse.

Anyway, answering Arv's question on voltage, I checked and get a steady 5.2V. So that doesn't seem to be the issue.

Thinking that i would put the sound issue aside, i decided to concentrate on the jet bumper that wasn't working. I suspected a poor contact somewhere and the bumper not registering that it is being hit... so i set to have a look. Under the playfield, next to the solenoid for the bumper, there are a couple of contacts. So i thought, let's close one and see what this does.
I approached one of the contacts prong with my insulated screw driver, touched the prong and immediately heard something (not sure what), but knew that it wasn't a good sign.
The outcome is now that my Excalibur does not want to start a game anymore...
I can switch it on, put some credit on, the lights are flashing, it is resetting all the targets, but i can't start a game. Nothing happens when i press start.

Help!

Please.
 
Clock it down to 4.9v, that's what I run my gottliebs at.
 
If contacts were OK on the pop bumper it then could be the pop bumper driver board. Often cleaning the pins with fibreglass pen and re-soldering the pins to the board can sort it. To check, swap it with another if you have one? Realise Excalibur only has one pop bumper.... ;)

However, what has gone bang !? I don't know what..... checked all your fuses?
 
Yes I checked the fuses and they are all ok.
I have no other boards to swap with.
Anyway I have called the cavalry: someone is coming to have a look for me...
I'll update after he has been (next week)
 
Sorry arv I didn't because I messed up the game before i could even try to.
At the moment I can't start a game so it is pointless trying to adjust the voltage to the sound card as I won't know the effects.
 
Its not the voltage to the sound card your adjusting, its to the whole game.
 
domlouis said:
Yes I checked the fuses and they are all ok.
I have no other boards to swap with.
Anyway I have called the cavalry: someone is coming to have a look for me...
I'll update after he has been (next week)
Click to expand...

Ok good luck. @myPinballs sells pop bumper driver boards if needed.
 
domlouis said:
Argh, things are getting from bad to worse.

Anyway, answering Arv's question on voltage, I checked and get a steady 5.2V. So that doesn't seem to be the issue.

Thinking that i would put the sound issue aside, i decided to concentrate on the jet bumper that wasn't working. I suspected a poor contact somewhere and the bumper not registering that it is being hit... so i set to have a look. Under the playfield, next to the solenoid for the bumper, there are a couple of contacts. So i thought, let's close one and see what this does.
I approached one of the contacts prong with my insulated screw driver, touched the prong and immediately heard something (not sure what), but knew that it wasn't a good sign.
The outcome is now that my Excalibur does not want to start a game anymore...
I can switch it on, put some credit on, the lights are flashing, it is resetting all the targets, but i can't start a game. Nothing happens when i press start.

Help!

Please.
Click to expand...


If you have shorted something on the playfield and now the game doesn't start, then you have most likely fried part of the switch matrix circuit. Most likely the return side.

Regarding your sound issue. The sound board has various sections that are all mixed together to provide the full sound. If you have no music then part of the board is not running. This is the section that also flashes the led. Do you hear any drum beat or silence except for effects?
 
myPinballs said:
If you have shorted something on the playfield and now the game doesn't start, then you have most likely fried part of the switch matrix circuit. Most likely the return side.

Regarding your sound issue. The sound board has various sections that are all mixed together to provide the full sound. If you have no music then part of the board is not running. This is the section that also flashes the led. Do you hear any drum beat or silence except for effects?
Click to expand...

Just silence except for the effects
 
Have you done all the ground mods by the way?
 
Check YROM1 that probably is kaput. (on the sound board)
 
The order for long term reliability mods on 80b games is:

Step 1: Ground Mods (as arv linked to) though later 80b games were much better than earlier ones, as gottlieb changed the connector design later and improved it (slightly!)

Step 2: Replace 12v filter capacitor on transformer panel (and 12v bridge rectifier at same time).

Step 3: 5v power supply rebuild / modification to fixed 5v design plus new connectors
 
Well I watched Todd's tip. And then I went upstairs to check. And I can see it wasn't done. So that's another one on the list of things to do.
 
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