System 80 Driver Board / Gottlieb Q's

[silverball]

Marty - Check all the playfield fuses and EVERY coil on the machine.

I have three driver boards in front of me, and all three have still got the original transistors (8026). So if you have the 2n3055 transistors installed, then the ORIGINALS may have been replaced at some stage. Someone may have replaced the transistors due to a fault during its route days.

I'm measuring .674 on all collectors, nothing on the emitter. This is with the board out of circuit. All my boards are out of projects, so they are untested.

You are welcome to borrow my board.

Bit of an update re the strange readings...

Big thanks to Silverball for his help this morning   

Basically to cut a long story short the readings are due to my multimeter.  Its not a real cheapo but not an expensive one and has been OK up to this point.
I tested the same transistors with Dave's multimeter (a good one) and identifed what the correct readings should be.  Hooked my multimeter up, completely different readings (inc null on the emitters).

So - instead I will get myself a Fluke (or one like Daves)....

I would gladly lend you mine but as you saw yesterday, my meter gets a regular workout. Fell free to pop in anytime and do some testing and the offer still stands on you swapping out any pcb that you may not be happy with. You may want to update the toasty pic of your driver board with the nice fresh one we gave you yesterday. (joking)
I would change settings to 240v, although as we discussed 220v wouldnt hurt.

[Strangeways]

Just shot you a PM Marty, answering your other question.  Sounds like the meter is faulty are the leads Ok.

Got it....Thanks.  I need to concentrate on either one playfield or the other...Just getting itchy feet whilst waiting for parts for the pcbs!

Any recommendations on a good DMM?

Also, any further thoughts on the powersupply, whether I should change the inputs from 220v to 240v?

Thanks again

I USED to have a Fluke - Best MM by far - but they are expensive. I had one for over 15 years. I've since owned two Jaycar MM and they are CRAP.

I'll be buying a Fluke as soon as funds allow - and a desoldering station.

Kudos to Dave with the excellent post sales service !

 

[Retropin]

You dont need to go splashing big bucks on a Fluke just to test a simple transistor. - Also just cos its a DMM and nice and modern doesnt also mean that it makes your life simpler. I hate DMM's unless reading a voltage as the correction factor due to internal resistance is minimal.
 Go spend $40 on an ANALOGUE meter. Set it to Ohms. Put leads on E and C on your transistor - any reading and its stuffed.

E to B should read high with leads one way and low with them swapped around - same with C to B.

In other words you have a "gate" that only allows a flow of electrons one way, if you get the same readings with the indicator sweep on the meter with red and black leads swapped then your "gate" is stuffed and so is your transistor.

Its by far the easiest way i know to test a transistor. DMM's are a pain in the butt

[MartyJ]

Marty - Check all the playfield fuses and EVERY coil on the machine.

I have three driver boards in front of me, and all three have still got the original transistors (8026). So if you have the 2n3055 transistors installed, then the ORIGINALS may have been replaced at some stage. Someone may have replaced the transistors due to a fault during its route days.

I'm measuring .674 on all collectors, nothing on the emitter. This is with the board out of circuit. All my boards are out of projects, so they are untested.

You are welcome to borrow my board.

Bit of an update re the strange readings...

Big thanks to Silverball for his help this morning   

Basically to cut a long story short the readings are due to my multimeter.  Its not a real cheapo but not an expensive one and has been OK up to this point.
I tested the same transistors with Dave's multimeter (a good one) and identifed what the correct readings should be.  Hooked my multimeter up, completely different readings (inc null on the emitters).

So - instead I will get myself a Fluke (or one like Daves)....

I would gladly lend you mine but as you saw yesterday, my meter gets a regular workout. Fell free to pop in anytime and do some testing and the offer still stands on you swapping out any pcb that you may not be happy with. You may want to update the toasty pic of your driver board with the nice fresh one we gave you yesterday. (joking)
I would change settings to 240v, although as we discussed 220v wouldnt hurt.

I would love to buy one like yours Dave, but cannot find them anywhere....Always the way with good stuff like that.
I will update a photo of the amost NOS board of yours.  You're a lucky man with such a treasure trove of so many spare parts!
I've got to replace a couple of transistors on this one too, but everything else is 100%.  I reckon it the transistors probably shorted in the first few months of its life and has been shelved ever since.!

[MartyJ]

You dont need to go splashing big bucks on a Fluke just to test a simple transistor. - Also just cos its a DMM and nice and modern doesnt also mean that it makes your life simpler. I hate DMM's unless reading a voltage as the correction factor due to internal resistance is minimal.
 Go spend $40 on an ANALOGUE meter. Set it to Ohms. Put leads on E and C on your transistor - any reading and its stuffed.

E to B should read high with leads one way and low with them swapped around - same with C to B.

In other words you have a "gate" that only allows a flow of electrons one way, if you get the same readings with the indicator sweep on the meter with red and black leads swapped then your "gate" is stuffed and so is your transistor.

Its by far the easiest way i know to test a transistor. DMM's are a pain in the butt

An analogue meter is no doubt a lot cheaper and for someone with a good foundation in electronics would be the best option.  Unfortunately for me, I'm still very much a noob in this area.  I can repair and my solder skills I would now rate as above average, but I still lack the basic knowledge of how and why things work.  When my year frees up a bit I'm still planning on trying to get a basic electronics course under my belt, along with an airbrushing course too!
I can follow the PinRepair guides now from start to finish, compare readings and replace whats broke.  Unforuntately I think a DMM would be a better option whilst I'm still noobing.
The problem with my existing DMM is that due to its faulty readings, I nearly went out and purchased a NOS driver board (but Dave came to the rescue!)...But still I don't want this problem to occur again as I will definately be doing more repairs in the months, weeks, years to come.
I can go out and buy another DMM from DSE/Jaycar etc...for $50 to $100 but the one common thing a lot of people are saying is buy a Fluke.  If there is an intermediatery DMM - ie between a chinese cheapo and a Fluke, I would be interested.  I'm not a professional so the top shelf stuff is not required, but I don't want a 'my first multimeter' either!