For repair on Bally early SS machines, is an oscilloscope used by many pinsiders? I bought a DMM and logic probe to help repair my Paragon but did not see many forum threads for oscilloscope use. How often would it be useful?
(Topic ID: 270163)
Almost never useful for a typical collector.
Probably rarely the right tool for the job even if you're doing professional board repair.
Mostly, an oscilloscope is not needed. However, there have been a couple of times where it would have identified the problem IMMEDIATELY. Here is the latest one:
https://pinside.com/pinball/forum/topic/power-supply-question-problem#post-5672016
A scope on +12vdc TP would have immediately revealed the problem.
I use mine all time, They are far more useful in determining not only signals but the quality and trigger points than a just a probe.
I don’t own a logic probe, so I used my scope a lot. Last night I used it to diagnose a bad switch matrix strobe by looking for the strobe pulses.
Spokane, WA
Agree about the usefulness of a scope. Try checking the quality of the non-overlapping 2 phase clock on a bally -35 with a probe. Easy with a dual-trace scope.
I built three Jye-Tech DSO 150 kit scopes, (around 20.00 each), one for the bench, one for my shop and one for my toolbox. Cheap, and like carrying a very deluxe logic probe. As the "DSO" part says, they are a storage scope, and allow you to scroll the waveform which is saved.
I put LIon batteries and a wireless charge aboard, so no external power supply needed. 200KHZ bandwidth, so most signals can be seen.
So: scope not necessary, but handy as hell, and my go-to for troubleshooting mpus, power supplies, matrices..
Rod
Yes, I use a scope when working on CPU boards. There is a trick to get some boards (Bally, Stern)
in 'free run' mode by removing all ROMs. This mode toggles all address lines so makes it easy
to find dead/shorted lines. While a logic probe usually works thats not always the case.
I'm an engineer with many nice scopes available. Not sure I'd recommend buying one to
those that don't know how to use one.
However, if working on classic video game boards, a scope is important.
Steve
I've reworked a couple completely rotten dead MPU boards (Sys6 and Sys11B) back to life. Did 99% of the work with a probe and DMM. I probably could have done 100% of it, but a buddy's scope proved handy for tracing some garbage in the signals - and potential lurking failure thresholds - that the probe couldn't distinctly detect. It's neat to see a noise pattern reveal itself on a screen, whereas a probe's beep pattern doesn't always reveal this. That said, I've fixed numerous other boards using only the DMM and/or probe.
I have an old Heathkit dual-trace scope that mostly works but blanks out on certain ranges. I'm not sure if "recapping" it would solve the problem or not? I did buy one of those $20 Jye-Tech scopes listed above but it seemed a bit wonky and difficult during its self-calibration. That said I've not really tried to use it yet.
I would say, until you've exhausted the capabilities and understanding of a logic probe, a scope isn't absolutely necessary. But it can certainly be handy and helpful in certain challenging edge cases.
A scope can be handy and new ones have become relatively cheap ($200-$400). Most of the time you don't need it, but when you do, it makes things so much easier.
Quoted from slochar:A scope can be handy and new ones have become relatively cheap ($200-$400). Most of the time you don't need it, but when you do, it makes things so much easier.
Ive seen quite a few cheaper scopes come on the market over the last few years. There are some that use a USB hub to connect to a lap top that work well, and can be had for under $100. My scope is a used Fluke 97 I picked up cheap a few years ago off Ebay. It works pretty well, but the batteries are shot.
There's probably better options now, but I got a "Rigol ds1054" ( 4 channels and soft-unlockable to 100MHz.) back in 2016 for an electronics project and it's come in quite handy for diagnosing issues in many projects since (https://www.mups.co.uk/post/2017/11/a-sound-improvement/). Not yet needed it for our pinball machine though, but I can see times having it would save diagnostic time.
If you do decide to get a scope, I'd look over the eevblog channel on youtube and their forums. Some quite knowledgable people on there with a good set of recommendations for best bang for your buck based on requirements.
@ zarco...As an engineer I would be surprised you wouldn't recommend a scope to everyone who was even remotely curious as to fixing things of an electrical nature, whether or not they know how to use it thats how you learn, A 25mhz analog for example can be had off E/pay can be had usually around 50.00... Fixing game boards is a different animal so to speak,, And this princess usually resorts to a Fluke 9010a, not a cheap machine (or even a scope for that matter) but rather a micro system troubleshooter that actually has the capability of looping signal triggers, and creating some seriously custom programs, Without removing the Roms...Just saying.
Ancient and slow but still works great for these old boards. Both of these were amongst the best $20 I ever spent. Tektronics 2465A OScope for repetitive stuff, HP 1631D logic analyzer/digital scope for watching goesinas and goesoutas to see which are working or not working. Learn to use these and a meter and you can fix most anything of this old slow stuff. Old 9010A - died long ago, I've got some old 9010A pods here somewhere. *If* I can find them, you can have them.
Twenty_Bucks (resized).jpg
For those asking about the 9010A pods. I had two --> Motorola 68000 and Intel 8051(8751). I used the 8751 a lot but never used the 68000 (which had broken pins and should be repairable). I have not seen these in several years and am still tearing my test equipment cabinet apart. Keeping fingers crossed...
Anybody ever use a Tektronix P6407 word recognizer probe? I found one of these in my cabinet and have no idea how to use it.
Guy in next office near me has one of those cheapie USB logic analyzers. I was rather surprised at how well it worked. And it weighs just a tad less than that 1631D.
In pinball, the oscilloscope is never needed. I have a nice tektronics scope and know how to use it. Sorry, Never had to use it on a pinball.
I'm an electrical engineer and have two oscilloscopes and I've only needed to use them twice in all the years I've been working on pins. If you're planning on doing a lot of hardcore circuit board work, it may be worthwhile, but for most pinball enthusiast, it is unnecessary.
Zeist
After much thought, I guess Jenn can see why some may consider scopes not necessary equipment ...Pinball is sposed to be fun, Not some self inflected torture of sleepless nights, and high dollar equipment...I have to change my answer here, I only have a dozen pins or so, and in reality rarely use a scope on them, Although I do use it alot on the arcade machines and jukes.
Quoted from Passave:After much thought, I guess Jenn can see why some may consider scopes not necessary equipment ...Pinball is sposed to be fun, Not some self inflected torture of sleepless nights, and high dollar equipment...I have to change my answer here, I only have a dozen pins or so, and in reality rarely use a scope on them, Although I do use it alot on the arcade machines and jukes.
Is there a root post somewhere I missed where you explain calling yourself Jenn or talk in the 3rd person?
I have taken some voltage a time or three, But usually gets worse after painting, hard life I guess, ...Sometimes I just talk to myself in the night.
Thanks for the helpful comments. I'll stick with the DMM and logic probe since I'm not planning on getting into board repair.
You are in the land of Tektronix since they are made in the Northwest. Look on Craigslist and pick one up. The 22xx and 24xx series are tanks. So are the old 4xx series.
I have a video digitizing business and own many 1980's and 90's industrial VCRs that I'm trying to handle basic repairs on. The repair books I've bought recommend old analog scopes like the Tektronix 465, 475 and the 2200/2400 series over the new digital scopes for functions like writing to the screen at the sweep speed and being able to evaluate waveform envelopes. I will probably pick one up for the VCR testing and use it for my Paragon if required.
2 weeks later
Quoted from catvilledoorman:Agree about the usefulness of a scope. Try checking the quality of the non-overlapping 2 phase clock on a bally -35 with a probe. Easy with a dual-trace scope.
I built three Jye-Tech DSO 150 kit scopes, (around 20.00 each), one for the bench, one for my shop and one for my toolbox. Cheap, and like carrying a very deluxe logic probe. As the "DSO" part says, they are a storage scope, and allow you to scroll the waveform which is saved.
I put LIon batteries and a wireless charge aboard, so no external power supply needed. 200KHZ bandwidth, so most signals can be seen.
So: scope not necessary, but handy as hell, and my go-to for troubleshooting mpus, power supplies, matrices..
Rod
Been thinking about a cheap scope or two too round out my toolbox now that I'm digging further and further into mpu repairs.
yeah, can't get much cheaper than those Jye-tech kits. Limited as to speed - 200khz, but like those old radio shack scope/probes, now unobtainium, they will tell you if you have a valid signal. Small, but add a battery for travel, or carry a 9v wall wart.
Also, as many have pointed out, scopes are relatively cheap new these days, and ebay has some good deals for the wary...you could get junk. Great for learners.
6 months later
Quoted from Zitt:Poor guy looks abused... broken knobs.
Maybe this machine will be the subject of my next restoration thread. Haha
To be honest I rarely bust out the scope and I work on pinball circuit boards every single day. It is a fun tool to screw around with, but not really necessary for most things pinball. Logic probe and DMM with frequency counter is a lot more simple and I would say get used to those before going to an oscilloscope.
The Miniware LCR tweezer is a great replacement of the old Radio Shack probescope.
I thought I saw a video of this thing having a scope function, but I may be wrong.
Anyway has a lot of great functions for pinball pcb repair
EEVBlog is full of great videos about 'scopes:
https://www.youtube.com/c/EevblogDave/search?query=scope
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