Star Trek: The Next Generation
Williams, 1993Hi,
I would like to get help for a problem whith flashers. In test mode or during the end of game sequence, these flashers turns on but very weakly, almost no nothing, on the insert and the PF. Could someone help me identifying the problem ?
Thank you in advance
Just trying to clarify if they are *always* dim, or only dim in test and attract. And are *all* flashers dim, or just some. Go in to tests and let the flasher test run. You'll probably have to hold the white interlock switch plungers in.
How do they perform in the flasher test?
Ok, I have done things in details. Plse, ell me if more detailed exlanation is needed.
First of all, for the end of game flashers, almostnothing on the pf, on the insert, weak.
For the test mode, it is a bit strange. #20 jets is ok, #21 pf is ok, #21 BB is ok. 22 nothing, the 3 blue shield flasher, nothing.... on the BB nothing.
Never seen that.
Quoted from cody_chunn:Just trying to clarify if they are *always* dim, or only dim in test and attract. And are *all* flashers dim, or just some. Go in to tests and let the flasher test run. You'll probably have to hold the white interlock switch plungers in.
How do they perform in the flasher test?
I agree - you might have a connector in the wrong spot very easy to do in this game. Its keyed the same as another the flashers will work well sort of. Some will blow, some will be lit all the time, others are dim.
Hi, Sorry I have 6 hours lag with you.
First, I measured voltage in game over mode, on the lugs of BB and PF flashers which are weakly lit or not lit all. 21Vdc on each. I also checked the location of J107, J122,J126 (PF) then J106, J124,J125 (BB) and checked voltages. They are ok. I replaced some dark bulbs, nothing changes.
Then I went in test mode - all lamp + flashers. On some flashers, no voltage at all. On others, the dim ones, a weak 0,3 vdc oscillating with the test pulses. I would have expected up to 20Vdc at the time the line is grounded.
It is not a single phenomenon. It applies to all. That's where we enter the Twillight Zone 
Thanks for going on with your support
You have 2 kinds of flashers, #89 and #906. Make sure you're using the right flaslamps.
Question: During flashlamp test do the Jets (#20), Right Popper (#21) and Middle Ramp (#22) flash brilliantly? Just wondering as these are all #89 lamps.
Check TP7 on Power Driver Board for +20 VDC (LED5 should be lit).
Reseat and verify they are in the correct spot, J107, 106 and 108. Inspect them for signs of scorching.
Test voltages at the lamp sockets. With the lamp OUT, you should see +20VDC one one side, nothing on the other.
For the 906 wedge base sockets, check inside them for signs of arcing and scorching. There will be a powdery film present if it's been arcing.
I checked the bulbs, they have all the proper type. As a complementary info, all flashers with #89 turn on dimmed but still visible, all #906 close to nothing. But even for #89, none flashes as it should. In no case they are too bright.
Then, I followed the schematic you sent. the output of BR4 is 21Vdc, TP7 as well, Led5 is lit when closing the coin door.
I reseated all connectors when removing the board for the BR4 voltage check.
>>> On lamp sockets, lamps OUT, I have 21 Vdc on both ends. I do not see why you expect a 0Vdc on one end in this case, can you please explain ?
For the quality of sockets, I am sure they could not have been bad at the same time in one week.
The only exception I see is the measurement with bulbs out.
Then I measure 3,2 ohms on R224 instead of 12 ohms as indicated in the manual. Anything which can put the flashers into trouble ?
Thanks again for the help
Honestly, if you remove both connectors, the 4 flashers you mention will not work, as these 2 connectors bring the Vcc to all flashers.
I checked F111. No issue with it, resistance close to 0.
Regarding your Voltage explanation, thanks for the schema. You expect 0 on one end, where I measure 21 Vdc on both ends.
Yes, you're right, my mistake. Then unplug J107 and see if the remaining flashers brighten up, then plug that one back in and unplug J106 and check for same. Does unplugging either connector change symptoms of remaining flashers? If the answer is NO, then unplug the 8 Driver PCBs involved and retry.
See if one set of flashers is causing the problem.
Re: fuse: a fuse and clips can show low resistance or continuity beep but still restrict current flow to the load. But we'll say the fuse and clips are fine.
You have me questioning myself on the voltage readings now... 
I keep looking at the circuit and can't see how there can be voltage on the LO side of the socket [lamp removed] without turning on the TIP 102 driver tranny.
The 21V on both ends (J107 and J126) is perfectly normal when the transistor is not grounding. You get 0V when the transistor is on.
*that is with good lamps installed*
Quoted from FreeBee:The 21V on both ends (J107 and J126) is perfectly normal when the transistor is not grounding. You get 0V when the transistor is on.
*that is with good lamps installed*
Right. But if the lamp is removed, the ON signal line drops to zero, does it not?
Hi,
A friend of mine helped me to find the problem. This is the resistor R224. Instead of .12 ohm, I measure 3,4 ohm. As a consequence the voltage is unsufficient to light the bulbs at full capacity.
My remaining question is: I need a wire wound resistance .12 ohm %5 CW10 on the internet. What is important to fully respect as replacement resistor specs ? I presume 10W is the max power that the flasher lamps can use, As I have 20 Vdc, the intensity should not exceed 0,5A, am I right or not ? how can I determine the ampere value of the downstream circuit ?
If I need the exact same specs for the resistor, Marco sells it, otherwise I would prefer to purchase here in the neighborhood.
Thanks once again so far for the valuable help and the schematics.
10W is the rated power dispersion for the resistor, as with most things in electronics it should be capable of handling some amount more than the circuit is actually designed for. The power rating and the tolerance (5%) are both very important along with the rated resistance. If you can find a .12 Ohm, 5%, 10W wire-wound resistor locally there should be no reason it won't be a suitable replacement. Of course lower tolerance and/or higher power rating would work (as long as it's not too big to fit in the physical space allotted) as well, but less than 5% are usually more expensive and / or hard to find.
Thanks for posting what the problem turned out to be.
You really had the problem figured out in post #9. Sorry I didn't pay enough attention to fully understand your comments. I totally blew over the most important bit about the resistor.
Glad you got it fixed anyway!
Just to clarify I was completely wrong about the voltage measurements on the sockets. You will indeed see potential voltage on both sides of the socket whether the flashlamp is installed or not...good or blown.
I'm a dumbass.
Once again my apologies for posting without my brain engaged. Where's the emoticon with an egg over the face...
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