Rochester, NY
Why would you put your meter on an ac Lug and a DC Lug? To measure the DC out you should be putting your leads on the + and - sides of the rectifier
(Topic ID: 180997)
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Quoted from StratDoc:I was texting the resistance of the rectifier. I thought to do that you put the black on positive and red on AC and look for a reading of 500-600.
You mean using diode test? In that case you should get a reading black AC->red positive and black negative to red AC, and no reading if you reverse the leads, but that's when the rectifier is out of the circuit. Which voltage is the center rectifier? Is it a repro or an original bally board? The rectifier for the 5.4V and the 43V have a resistor across them, but the one for 11.9V doesn't, so there's a chance they'd get different readings.
Quoted from Mk1Mod0:OK. Then we know you have household current in. TP2 should be around 230VDC or so and if the lights are on in the coin door you should see 6-8 vac at TP4.
Note TP4 has to be measured in AC with the other lead on E8
Quoted from StratDoc:TP2 is 135vdc
That's pretty low, what do lugs 8+10 of the transformer measure (AC)? What about E5+6?
Quoted from StratDoc:You aren't he greatest!
Okay, all looks good except F4 blows as soon as I plug into J2 on the solenoid driver board. I have a 5 amp circuit breaker thank goodness so I do not go through fuses. I have rebuilt the board with a high and low voltage kits from BigDaddy Enterprises.
Unplug your displays just in case
Quoted from Quench:To clarify, these voltages you're measuring at the MPU board are DC. You keep mentioning AC
Unless they are getting AC, in which case there's a problem... 
Further troubleshooting the LED not even turning on:
1. One side of R29 should have 11+VDC. That powers the LED
2. the other side or R29 should have continuity to the LED
3. You should be able to test the LED with your diode test: black lead on the side attached to R29, red lead on the other side should show no continuity, swapped leads should get some voltage drop (and the LED might even light dimly)
4. R25 carries the signal from the PIA to the Q2 transistor to control the LED. With U11 removed, you should get 5VDC on one side of R107 (and a bit less on the other side). This 5V should then flow through R25 to Q2.
5. If there's near 5V where R25 connects to Q2, and there's 11VDC where R29 connects to the LED, then the LED should be on, unless you've got a problem with Q2.
6. I'd test every component in the circuit against the schematics, and the continuity between them to be certain
Quoted from Quench:Slight typo above, R25 should read R28
Oops! Darn PDF scans...
Quoted from Quench:This indicates a problem with the LED
Curious- why with the led?
<1V seems low to turn on Q2 to me
Quoted from StratDoc:Less than 1 volt at q2 on all legs.
At least one of these legs should be connected directly to ground. When you say <1V, do you mean 0.8V, or something like that? One of the legs should read <0.05V
1 week later
3 weeks later
Quoted from StratDoc:Quench,
Making progress but have hit another impasse. So in attract mode most of the lights now flash and sequence, but I still cannot get some lights to come on regardless of wether I connect to TP3 and touch leg G or ground and touch leg A of the corresponding transistor. I have replaced U1-U4 chips - this is why most of the lights now sequence and flash properly. Other things I should check? All sockets are good. I can ground a wire and touch the socket and get all non-working lights to work.
Check for cold solder joints where the light connectors are attached to the board. Could also be a bad pin in the connector
3 weeks later
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