I would say: Yes. I believe the CPUs are only running at 4MHz so the 20 should be more than enough.

If you want something a little less expensive and easier to use, there are other options like the Velleman hand-held scopes. Yes, they only have 1 probe on them, but I've used mine extensively on board repairs, and they do store memory so you can compare waveforms.

ebay.com link: Velleman HPS 50 Handheld Personal 40Mhz Oscilloscope

That one is only at $50 + shipping right now. Will probably sell around $100 I'm sure.

These look tempting, but I'm not sure about quality and would be skeptical based on that price: ebay.com link: ARM Pro Pocket Sized DSO203 Nano 4CH Mini V2 Quad Handheld Digital Oscilloscope

Your skepticism is warranted.

#t=21

Crappy resolution, no input protection, not very useful.

But to OP, agree, your free scope is fine.

viperrwk

Yeah, I wish someone would just give me a free scope. The Velleman isn't bad at all though, just tough to view the screen because the refresh is slow. I never got lucky with eBay with older analog ones.

to be fair... I'm a 20 year embedded sw engineer who is around Oscopes every day. I've never needed one on a pin in 10 years.

Everything can be done with a general purpose multimeter

How do you troubleshoot a data or address line problem or a sound or video problem with a multimeter?

I'd like to know this too. I'm considering buying a scope, but will save my money if I don't need one.

I break out my fluke scope meter on troublesome CPU boards, but for most problems a logic probe and DMM is all I use.

The only time I crack the oscilloscope out is for early ss issues. I can't say I've ever needed it for any WPC issue.

I actually use a DSO203 Nano as my "mobile scope". It's not a bad little device, but it's far from perfect.

I have a logic probe and a DMM and I'm trying to learn how to use them to diagnose a sound problem I'm having on a Data East sound board. Can you explain to me the steps you take to use these tools to find the problem you're after? I understand that ICs have inputs and outputs and I use their data sheets to determine those, but I feel like I'm missing something.

Here is a very good (pinball related) site of how to use a logic probe (read all 4 pages):

http://www.techdose.com/electronics/Using-a-Logic-Probe/395/page1.html

+1 me too.

I have an old Tektronix 785 on a roll around cart for my workroom, but use the Nano in the gameroom for quick checks/pictures.

Thanks. That did fill in a few gaps for me.

I use a Wittig Oszifox scope on board repair work, but it's something I break out very rarely. Usually, a logic probe and a DMM is all you need.

Considering the price (free), give it a try, and if you find it doesn't do what you need, then perhaps it's time for another - but I doubt you'll use it much!

YES, what a great tool, I have it too ... I first saw it on former pinrepair site ... unfortunately the company Wittig went bankrupt a few years ago ...

I agree. I rarely use my scope. Get a good DMM and a logic probe.

You don't need a scope for everyday repairs, but sometimes it is a giant time saver.

Especially when tracking down hum in soundboards.

I apparantly need a lesson in analogue signals with the scope. WHat the heck does the hum look like. Analouge sound stuff is the hardest for me to repair.

Uh oh, time for Vid to write another guide!

I'm an EE... so would like to be a Scope elitist. However, for personal electronics; I tend to buy cheaper items. I can't afford 18k for a Tek scope at home.

I use a Temna 2channel portable scope (20mhz) for debug in the machine ... usually when debugging my own circuits vs originals. On my bench; I have a Rigol 2channel 100MHz I think.

Here is a good guide:

http://www.instructables.com/id/Oscilloscope-How-To/?lang=de

And here you can learn a lot too:

http://www.doctronics.co.uk/scope.htm

I'm already working on it.

Looking forward to reading it.

Agreed. Use my scope to track down troublesome game resets. Noisy dc voltage lines do to bad filter caps.

Reading over that thread. A lot of great advice, by a lot of good people in there. Sounds like you tried everything I could think of. I would of thought it would be the fliptronics board, but you said you swapped it.

Some pins read high and low on my logic probe. However, I don't see that represented on any of the truth tables I've looked at. Those are only either high or low. How do I use the truth table if my input or output is both high and low?

The truth table is for a slice in time. So the truth table for an inverter tells you that when the input is high the output will be low and when the input is low the output will be high. As you are seeing though many circuits are pulsed, so when the input pulses high, the output pulses low and when the input pulses low, the output pulses high.

Depending on the circuit, and the logic probe, the reading should show up as low--pulsing high or high-pulsing low. With the opposite reading on the output of the inverter. Of course this doesn't apply on circuits where the low and high pulses have the same duration.

I can't imagine troubleshooting xtal, reset generator signals, data address lines, IRQ, & VMA using just a multimeter and logic probe.

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