Recent content by joetechbob

Hi! Have 3 newer Paokai manufactured crane games (Double Cute, eg) that I bought at auction but are missing manuals. This makes it nigh on impossible to run diagnostics, tweak difficulty, switch off attract, etc (dip switches and alphanumeric displays). Does anyone happen to own one of these...

Price drop to $1695

Spot 193 for sale. My cost is 2060, selling for $1795. Game is through pinball star. Buyer is responsible for balance ($6999), and any shipping/taxes.

So I decided to just go ahead and run jumper wires from 21.21 (~WE) -> 35.9 and 21.23 (A8) -> 23.3 ... Working great now! Passed memory tests and no more graphical issues. Thanks for the help, everyone!

Here's how my board aligned with the memory tests:

For future reference, here's what I measured (using IC.PIN convention). Note that IC 20 & 21 share address lines; IC 38 & 39 also share address lines. Road RAM stack 1 (broken): 20/21.1 (A7) -> 22.18 20/21.2 (A6) -> 22.3 20/21.3 (A5) -> 22.16 20/21.4 (A4) -> 22.5 20/21.5 (A3) -> 22.14 20/21.6...

Hi all. Took me a while here, as at the last minute I chickened out and decided to order a Hakko FR-301 before diving into this one. AMAZING tool -- expensive -- but, I wish I would have bought one long ago. The chip came out very cleanly and the corrosion wasn't too bad. I didn't see anything...

Thanks. I only have a basic bulb driven solder sucker, so I’ll probably just cut the legs on the RAM chip if it doesn’t want to come out easily.

I reached out to the memory test author to try to understand what the test is doing, and why it passes and fails the same memory address ranges. He got back and the short answer is double buffering with a "flip" happening between the two calls: "The road RAM is double buffered, and the...

Thanks for the input everyone! Waiting on parts before I dig in so I can try to knock it out in one last debug session. I’m hoping it’s as simple as a bad RAM chip/connection. I’ll report back with my findings either way.

Definitely. Already have an order in with digikey.

Good suggestion. I’ll run continuity checks. The corrosion appears very localized, so I expect only solder pads, vias and traces near or around that end of the chip if anything. Unfortunately I already ordered Toshiba RAM. I’ll keep that in mind for next time—wasn’t aware Toshiba was bad. Must...

Thanks. The corrosion looks pretty bad on IC21, so I'm thinking of starting w/ just removing it, installing a socket and trying a replacement chip. Unfortunately, it looks like I can only get TMM2015BP-10 from China. But, from what I can tell in the data sheet, TMM2015BP-90 should work as it is...

Winner winner chicken dinner! In all seriousness, I still need to test, but I can't imagine this mystery corrosion on IC21 (and a little rust on IC20) are a coincidence. It's funny that I didn't notice this when scanning the part and solder side for touching legs and corrosion. As an aside, I...

Looking at the source, I guess it's this, but not sure what that maps to in the hardware. Confusing part to me is that it looks like MSB0 and MSB1 use the same memory addresses per memregions.c, but MSB0 passes? I must be mis-understanding how the test works. ----- // Test road from main...