On my path of dicovering how many things you can break every time you lift the playfield on a pinball machine, I am learning that some things get more broke than others.

I have made a slight cock up wiring in one of the kicker coils, this has blown a transistor on the driver board. I have struggled for years with cheap soldering Irons and Meters that just don't hack it. So I have decided that an inverstment in some decent kit is needed, just looking at Maplins, this is the sort of thing (and price range) I am looking at...

‘Blue Arrow’ UT-70B Autoranging Professional Digital Multimeter

Temperature Controlled Soldering Station

I know there has been a couple of discussions about this recently, but I want kit that will work for an assortment of tasks. Any other kit tips would be welcome, ie what solder to buy? How to clean the boards (they are quite dirty)?

These Pinball Boards are not replaceable, so I want to make sure I do the best job I can. Any Thoughts ???

Cheers

Cris.

I've got an Antex 25 watt iron with a superfine tip, I can pretty much solder anything with it, I did my button lights with it and I'm confident I could do memory upgrade with it too now. I doubt you'd need temp control and the Antex is cheap and reliable, I've had it for nearly 5 years and it gets pretty regular use.

As for a DMM, a Fluke or an AVO would be my choice. Mindyou I've been using the same cheapo Maplin Fluke-ripoff for 4 or 5 years too.

That DMM you've linked looks interesting, what's the serial port for?

I've got that soldering station, Cris. The tips are quite thick, which is a good thing as they last longer. I've only had three grumbles so far and they are:

1) Maplin seem to stock the replacement tip packs sporadically so it is wise to order a replacement pack before you need it. Also, they only sell a pack of 5 assorted (and the iron comes with just one tip, a medium) so if you only use one size, it could work out rather expensive.

2) Maplin don't do a really fine tip in the pack. Having said that, the fine tip they do supply is just about okay for SMT stuff.

3) Their web site is pants.

Yeah, both of those look like they'd get your job done at a reasonable price. Don't know anything about either brand, but the specs look ok.

As to cleaning the boards, warm water should be your first step to get the worst off. A cheap toothbrush can help. Avoid detergents beyond those that you'd be ok with on your skin (ie washing up liquid should be ok), and make sure that anything that you do use is well rinsed off. Allow the boards to dry thoroughly before plugging them back in - preferably a day or two in a warm dry envrionment to ensure that all trapped moisture is removed. Be careful if you decide to use your airing cupboard for this - nylon and dry air can create a static hazard.

The only other thing that you should use to clean boards is isopropyl ethanol. This might be required if there is old flux residue present.

The serial port is to link it to some software on the PC I think, more info on the Uni-Trend Website. It's not a feature I would find a use for, although it may have some cool factor One of my testers at work links to software on the laptop via bluetooth, doesn't do anything extra (just shows results on the laptop screen) but it's kinda cool.

I once heard of a chap washing PCB's in his washing up bowl, and then blasting them dry with compressed air. We have loads of compressed air in the garage were the pinball is at the moment, the boards are 11 years old now, do you think this will do more damage than good?

Cheers

Cris.

Usually, serial connection on a DMM is used to log data on the computer to draw trends.


I currently have a Protek 608 at home and I'm quite satisfied. My father have the model "below", the Protek 506 and I think I prefer his : better layout of the functions and Power is on a push button, not on the main dial. He can let the dial at the function he uses often and only press the power button...

A feature I really like is temperature... it's always useful to have a thermometer for up to 1200°C :-) No joke... I wanted to test if my oven was properly calibrated: My mother though it had 50°C error... No! it's ok.

The only thing I changed, and it's because I had better ones already at home, are the probes. The included ones have wire not flexible enough for my use.


If you search a bit on the net, I'm sure you can find a few good deals for these... ebay has some too.

Well, I can recommend the Voltcraft VC-820/840 DMM, available from www.conrad.com. These have pretty much identical specs, are reliable, and most importantly, are rather cheaper than the maplin one. The 840 has in addition to the normal V/I/R etc measurements, temperature and true RMS measurement. They both have serial ports for linking to a PC. The 820 is currently listed at about 50 euros, the 840 at 77 euros.

They also do quite a nice soldering system, the LA50 digital soldering station, for 75 euros, which I would say is superior to the maplin one. Whatever you get, buy spare tips at the same time.

I would suggest that you get 'savbit' solder, which has a small amount of copper in the mix. This protects the iron tip from erosion to a considerable degree and also improves the wettability of whatever you're soldering, which may be important with old, oxidised joints. Get something around 1-1.5mm diameter for through-hole work, perhaps 0.5mm for SMT work. DO NOT use any acid-flux-cored solder on electronics work! It's not likely that you would, but I have seen it happen and the results are not pretty.

Get a flux pen, such as this, and use it liberally when soldering. It will make an enormous difference. Also, use solder braid to remove old solder. It works much better than a desolder pump.

For cleaning the PCBs, I would suggest vacuuming out the crud that will almost certainly have accumulated on them, then using isopropanol and a toothbrush. Rinse with hot water, shake off as much as possible, dab off the remainder with paper towel, and place the PCB somewhere warm to dry for a few hours. Try not to immerse electromechanical components such as relays, solenoids, or switches in either the IPA or water. Don't worry about the water on the electronics, as long as there is no power and the water is clean, no harm will occur. (electronics don't mind water as long as you dry it off fairly quickly, but really don't like soft drinks! If you spill something on a PC keyboard, the best thing to do is spray it thoroughly with warm water in a shower, possibly with a little washing up liquid, then hang it up to dry for a day or so. Usually this fixes them quite nicely)

I would avoid compressed air unless you have some experience, it's quite possible to blow surface mount chips clean off the PCB if you get the pressure wrong (trust me on this )

pca

Is it really necessary with savbit solder anymore? I thought all decent soldering irons had plated tips nowadays. And isn't 1-1.5mm solder too thick even for THT? I only use 0.5mm solder, as I have a lot more control of how much solder I apply...

Stig

Yes, decent tips do indeed have a plated surface. Even indecent ones do. However, it's quite easy, especially when dealing with inexperience and large component leads, to puncture the plating. At that point, you find out rapidly how soluble copper is in molten lead/tin alloy (hint: extremely )

I personally use .4mm solder for most things I normally work with. However, for heavier work, larger diameter solder can be very useful, since you don't have to feed it into the joint so fast. Pinball machines that I have seen use fairly chunky connections, and large components on the PCBs, and my feeling is that very fine solder would be irritating to use under those circumstances.

pca

Same principle. I used to use my mother's dishwasher for cleaning motorcycle engines (it was a big dishwasher in a restaurant), and it worked nicely for that as well. Useful things, dishwashers.

You can do more damage with an industrial microwave oven, though...

pca

Yeah, but the dishwasher is a little more plug and play insert and clean.