Arcade Collecting > Pinball

I finally got a pin...RESTORED AND LOVING IT.

<< < (36/52) > >>

ChadTower:
Could it be a diode that shorts under current but reads just fine with a DMM?  I've seen those a couple of times.  I was told it's the final stage before true failure - the PN junction just can't handle current but the tiny flow that the DMM puts out doesn't cause an issue.  IIRC wear failure results in a short and overvoltage backwards causes an open but some diodes will go into a harder to diagnose intermittent state like a leaky transistor (which, of course, is just a couple diodes anyway).

shardian:
I pulled the board and booted it on the bench. Used my pocket scope to read the inputs of the suspect chip. Each strobe line is represented by 2 pins - an input and an output. The spider chip represents the input side. If everything is normal, both pins are pulsing. If  the input pulses but no output, the TTL is bad. If neither pin of a matrix row pulses, no soup for you! In short, diodes had nothing to do with it.

I did go ahead and finish putting in the replacement chip and attached the battery pack. When I first turned the game back on, it was acting very weird! All kinds of stuff was acting funny. After a while, I realized the problem: I had switched out the game prom to the other board, and currently had a Pinball pool prom in the 'working board'. I rectified that problem and got back to mostly working condition. I supposed it is the addition of the battery pack, but the game does act up a bit more now. Pushing the start button too many times puts the game into service mode - as in the start button functions as the service button. The service button does nothing.


In the end, I now know that everything on the cabinet works except for the main board. I will keep an eye out for a tested 100% CPU, or just ask Santa for a repro cpu. I have played this game enough to think that I would like keeping it around for a while. I do like the playfield for the most part, and everyone who played it at the party yesterday loved it. At this point I just have to see it thru as a restored machine.

shardian:
On a whim, I decided to start tearing the playfield down last night. It is a pretty straightforward process. My 18 month old girl took a keen interest, and 'helped' me a bit. I thought it was very cute until she started losing posts when I was looking away.  ;)

Anyways, most of the metal posts are really nasty, with what I assume is crusty wax/cleaner. The plastics are all warped from the lamps. Good news though is that all posts are present and in good condition. The only thing cosmetically I really need is a set of lane guides for the top rollovers. I can live with that.

Anyone know of a good way to remove the top part of Gottlieb pop bumpers?

shardian:
Heh, it pays to work with a bunch of hardcore hunters. I am going to be able to borrow a vibrating tumbler to polish all of my small metal parts over the weekend.  :cheers:

shardian:
Currently I'm tumbling small batches of hardware. My opinion so far of the tumbling method is 'meh'. Things that looked good to start with look a little better, and things that looked like ---Cleveland steamer--- are now clean at least. It doesn't work miracles on anything that has lost its plating, so I guess I will eventually replace my shooter assembly. The biggest plus to using a tumbler is that there is no work involved. You just dump it in, then sift it out. Picking a few chunks of media out of screw heads is far less work than hand cleaning/polishing every post/screw/small hardware.

I did a test run on cleaning white plastic posts, and it is not easy/not good results. Is there a simple, fast method to brightening these things up with Novus?

I also cleaned the plastics in prep to flatten them. Everything I read says to use windex. I instead went with Mean Green. That stuff is a kick-ass cleaner! Other than being warped, the plastics look brand new. The heat browning just melted off the back side, and the fronts looked shiny and polished.

Another poll question: Have any of you all flattened plastics? If so, what method did you use? I am leaning towards either the heat gun, or holding them over a camping stove.

Navigation

[0] Message Index

[#] Next page

[*] Previous page