because, for me the uln2803 test would be done in ttl both power driver board and cpu board

I am confused with this of the integrated being ttl or cmos

this link (https://wiki.arcadeotaku.com/w/Logic_Probe_Guide#TTL_chips) says that the integrated 74hcxx family is TTL
the integrated 74hc237n is TTL

but the inthegrado 74hc237n is not cmos ?

thanks,

because, but so much because the logic probe in cmos or ttl

how to test the integrated hv5308pj ?
this integrated is used in the display of the flipper machines

according to what I read on this link (https://web.archive.org/web/20180330190727/http://www.pinballrehab.com/1-articles/solid-state-repair/tutorials/122-electronics-tutorial-test-equipment) about ttl and cmos.

The link on the page that I sent you says TTL logic circuits are always 5 volts and CMOS logic circuits can be either 5 volts or 12 volts.

is that the integrated ttl are 5 volts and the integrated cmos can be 5 volts or 12 volts.

Bump for a great thread and another real world example since I can't seem to find how to test a 4514 CMOS.
Trouble shooting lamp 33 (J11-1) on my Bally Atlantis, in looking at the logic diagram in question, I need to test pin 20 which signals Q65, how on earth do I find pin 20 when the chip has 12 pins per side?

20180625_200228 (resized).jpg

20180625_200246 (resized).jpg

Not positive this is the right datasheet. http://www.ti.com/lit/ds/symlink/cd4514b.pdf

Thanks, so my arrow is pointing to pin 20?
Since it is for flasher, would I expect a pulse signal?

20180627_152957 (resized).jpg

Correct.

I know this is an old thread, but after skimming through it I'm still not sure how to set this up. I have a Mousin' Around (System 11B) that's doing something weird on the display, and so I need to figure out where the signal is being messed up. Where should I put the red and black alligator clips? I'm assuming 5-volts (Looking through the manual I'm guessing U41 is TTL), but I have no idea where "5-volts" is. I'm also not sure where ground would be on the board.

Thanks! I didn't think to read the board itself, just the manual.

Nope, at least none that I can see. I've detailed my progress with the issue here: https://pinside.com/pinball/forum/topic/system-11-all-comma-segments-lit-on-left-display-pinled

Currently pin 17 on U41 doesn't have any signal at all, while the others do.

I got the Elenco probe suggested, but testing a couple chips on my Strikes and Spares lamp board, the sound changes when the bulb I'm probing for lights up, but the high/low indicator never does?

I am unfamiliar with whether or not a logic probe has continuity but is it possible by testing the bulbs you are grounding a transitor?

I'm not testing the bulbs, I'm probing a chip on the lamp board - the sound changes when the corresponding light turns on, and changes again when the light turns off, but the high/low state indicator on the probe never changes -

First thing to do is pull up the data sheet for the IC your probing. Confirm if it’s TTL or CMOS. Set prob jumpers to appropriate voltage and ground.

Then from the data sheet identify which legs are supposed to do what. High-low-toggling exc.

Remember the corresponding leg could be held high or low, change state from high to low or low to high, or toggling from high or low.

I would look through your manual to understand how your probe interprets signals.

Once you understand what the probe is doing. Then identify if what you see on the probe matches to what is shown on the data sheet. If not you could have a problem with that chip or possibly some component beforehand.

Its a CMOS chip, and the entire circuit is working fine, it ended up being a cold solder joint - here's the chip below (original is obsolete, that's the replacement) from both the datasheet and the lamp board schematic.

Pins 5 and 6 are both feature lamps, so I was comparing those and the results were identical (like i said, problem wasn't the chip). No manual came with the probe (ELENCO 560), but if the chip output is controlling a lamp, it's obviously changing state, no? As I said, the staticky SOUND changed when the corresponding lights lit up, but the HI/LO indicator on the probe never changed - if i remember correctly it just stayed low -
chip (resized).PNGchip 2 (resized).PNG

Well, the obvious check is to try and few other circuits...hell, just probe the 5v test point and see if your probe behaves as expected.

Yep, probed the test point, it goes HI.

Probed the legs I was working on earlier, it stays LO then the PULSE light comes on when the sound changes/bulb lights up.

So I guess by looking at this truth table for that chip, all of the outputs are going to be LOW -

Capture (resized).PNG

This is the correct indication. See @terryb's 5th post in this thread.
In this application, the 4514 pins are mostly low except for a very brief high pulse on outputs enabling a SCR to illuminate its respective lamps.

Ok, thanks Quench (and Terry B)!

I see what Terry said now - "Also remember that IC datasheets are your friend. The datasheet for any IC will typically provide a truth table that will tell you what the output should be based on the possible inputs."

So Quench, as someone who's repair experience is well documented on here, how often do you use a truth table to determine what an output should be? Is it considering "cheating" as opposed to deciphering a circuit to figure it out? Or when it comes to these Bally/Williams games, do you have these various chips memorized by now?

Thank you for your guide. I’ve ordered a logic probe and test clip to aid in my troubleshooting. I’ve also ordered a test EPROM.

I’ve got a data east Lethal Weapon 3 for my first pin purchase. Totally inop when I purchased it. I’ve got everything working at this time except the ball launch solenoid. It is locking on when I power up. I disconnected coil and installed new coil diode. For the time being I’m leaving coil disconnected. Replaced Q4 on PPB ( it was shorted on). The predrive transistors on MPU check good. The IC 7408 driving that coil circuit had been replaced by someone and a socket installed. I screwed a leg up getting the IC out and have a replacement being shipped. It’s a Chinese 7408. I hope they are legit. Also have a vintage version of 7408, SN74F08N enroute.

My questions are

1. Can I test the solenoid output on CN12 with controlling IC removed? It seems this may be a way to make sure Q27 and Q19 are not shorted. They test with a DMM identically to the other transistors in that area. I realize there will be no logic with IC removed but maybe a continuity test?

2. Reading a wiki guide online made me realize in the upper right of the MPU I have a special solenoid output area that is not used but may yet be shorted. If I determine a diode is shorted in this area can I just remove the diode or must it be replaced?

Thanks for any help you may provide.

I would put your inquire in the LW3 club.

Will do.

This guide really helped me troubleshoot my LW3 solenoid issue. Without the use of a logic probe I would have never found corrosion under my header pin connector at CN12 on the MPU

Thanks for the tutorial.

I want to know what happens if you accidentally probe a higher-than-5V line? Say for example, you accidentally probe a 12V line.

The probe is comparing voltage to ground and indicating if it is high or low relative to ground and the reference voltage. It gets the ground and reference voltage from two leads that exit the probe and you clip on test points provided on your CPU, MPU, PPB etc.

So, If you reference 5 volts and touch 12 volts with the probe it will indicate high. I am not sure what protection is provided in the probe for preventing damage to the instrument. I can say that I probed many points during my troubleshooting without regard to the voltage of the circuit and saw no ill effect on the probe.

The best use is on the pin outs on the CPU/MPU where you are trying to determine if it is sending the proper logic/signal to the PPB (high power board that is the interface between the CPU and the playfield devices). I was able to eliminate the CPU as the problem or identify it as the problem on a number of circuits by comparing the signal output with known working pins in close proximity. For example place the pin in diagnostic mode through the DMD menu and enter the "coil test" menu. Take a coil test that you know is functioning and probe that pin as you activate the coil. Observe the probe's behavior. Then, test your faulty coil and observe the probe's behavior on that pin. If they are identical you know the CPU is sending the proper signal and your issue must be downstream. Then perform the same test where those outputs enter the PPB (playfield power board) and observe that the signal is reaching the PPB. Then perform the test on the PPB output pins. You can see where I am going with this troubleshooting.

I also discovered corrosion under a header pin assembly by hearing the erratic buzzing from the probe even though the indication was correct. The tones the probe makes are very helpful. I ran alcohol under the header and the sound changed to a clear tone and reverted back to a buzzing when I taxed the header under game use and within a few moments the circuit failed again. This alerted me to the header being the issue. I unsoldered it and sure enough there was some resin corrosion ganged up around that pin's pad. Cleaned, resoldered and voila!

The CPU and PPB are primarily dealing with "taking ground" to the devices. This fact probably reduces the chances of damaging the probe. You can also probe the CPU chips and compare findings with a logic map of your chip (example 7408 IC). I would compare chip outputs with known working outputs on the same chip. Then move from the chip to the transistors and map the logic to make sure the switching was occurring as planned. You will need to google the data sheet for your IC to determine the input and output pins for each circuit and the logic of the circuit. As an example my problem was on pins 4, 5, and 6 of a 7408 chip. 4 and 5 are input pins and must both be "high" to get a valid "high" as an output on pin 6. If your IC logic is not comparing favorably with the data sheet logic map then your IC is toast. I replaced one of mine.

This process taught me how an integrated circuit and a transistor worked. Something I had never seen put to practical use and understanding.