Pinball Lamp Issue

FrizzleFried

Well-known member

Donor 2011
Joined
Mar 20, 2007
Messages
54,193
Reaction score
5,245
Location
NAMPA, Idaho
I have one lamp that is really starting to piss me off. It worked fine but then this morning it went out. After messing with it I got it to fire sort of in REVERSE of everything else...

When the lamps all pop on, it's on too but low voltage... when all the lamps turn off it gets REAL bright...So I figured I must have screwed up the socket so I stick another socket in there... same thing... runs when everything else is on but dim, then when everything turns off it gets bright.

What did I do wrong?
 
Being a older game I think you have more of a wireing prob shorted to high voltage since it is only one bulb but still that usually blows all in the circuit. What bulb is it.
 
Being a older game I think you have more of a wireing prob shorted to high voltage since it is only one bulb but still that usually blows all in the circuit. What bulb is it.

It's the blue N for XENON in the middle bottom of the playfield.

I tested by running some leads to a lamp outside of the pin and it's doing the very same thing... dim while lamps are on and bright when the rest are off.
 
There is a section in the pinrepair guide that talks about lights being dim/bright/dim/bright. The section refers to pop bumpers but i think its just an example. Might want to check into that.
 
There is a section in the pinrepair guide that talks about lights being dim/bright/dim/bright. The section refers to pop bumpers but i think its just an example. Might want to check into that.

Now that gets a little complicated.

The damn thing worked YESTERDAY... suddenly for crying out loud.
 
...so what exactly has happened with this lamp?

The bare wire running around the bottom of the playfield is the 6VDC "hot" wire from what I understand... and the individual colored wires going to the lug of the lamp is the ground. When the light is supposed to turn on, the CPU connects the ground wire to ground and the lamp fires... right?

So, if it's always on, it sounds like (to me) the ground wire is shorted somewhere? I just don't get why it goes from dim (while all other lamps are on) to REALLY BRIGHT... unless it's dim when all other lamps are on because of the load on the 6VDC line and then goes real bright when all lamps turn off as it's the only one being fed the 6VDC (no load)? That sounds right, aside from the fact that when it's dim, it's dimmer than the rest of the bulbs.
 
You have a fucked up lamp driver SCR for that particular bulb. Look on the schematic for the Q number and replace that one particular SCR.
 
You have a fucked up lamp driver SCR for that particular bulb. Look on the schematic for the Q number and replace that one particular SCR.
Damm Ken, You Dropped the F BOMB.
Did You Get it Figured Out Frizz. From what I see it is Q13
 
Last edited:
Back
Top Bottom