Gang:

I recently inherited a High Speed with all kinds of matrix issues, both lamp and switches. Let's start with switches.

Rows 1,2,3 all register as the switches assigned to row 3. For example, switches 1,2,3 all show up in switch test as switch 3. This is consistent across all columns in rows 1-3. I have repinned the molex header associated with all rows.

Now, on to lamps. Pactically every lamp, when tested in single lamp mode, triggers multiple lamps. Most lamps result in four to six other lamps lighting which are not all neccessarily in the same row or column.

I am going to preform the matrix test by removing their associated connectors connecting a jumper/test bulb, but am wondering if there is anything else I should consider in the trouble shooting process.

Any feedback shared is appreciated. Thanks!

Update.

After performing the matrix test, I discovered the following.

All of the wires are in the correct position in the female headers.

When I test row 1, column 1, it reads row 8, column 1. It appears the wiring for J8 follows the schematic, but J10 is the reverse order of the schematic. Leaving my clip on J8-1 and probing the pins on J10 went as expected, but in reverse order. I could have simply reversed the order of the wires, but know that my issue would have persisted as the last 3 pins (7-9, and again, this should have been the first three) all came back as the same switch on row 3 - in the case of J10-1 to J8-7,8,& 9, they all read J8-3. In the case of J10-2 to J8-7,8,& 9, they all read J8-11.

So, is it safe to conclude that I have a board issue?

Is anyone aware of a mistake in the High Speed manual when it comes to the matrix?

I only get one switch lighting up at the headers. However, it's the wrong switch for rows 1 & 2, regardless of column. Those always come back as the switch associated with row 3 (always same column).

Rows 1 and 2 definitely have a problem as those aren't coming back at all when probed at the boards.

Good feedback, barakandl, I will go there next.

Barakandl, finally got time to pull the board out again and test those resistor arrays associated with the switch matrix... and you called it. Those pins in question are all failing... reading as open.

Order placed to Great Plains. I'll replace SR11 and provide an update afterwards.

Any thoughts on where my lamp matrix issues might be rooted?

Replaced SR11 and a couple of other blackened components in the switch matrix circuit and all of my functionality is back. Thanks for pointing me to the SR component.

Now, to tackle the lamp matrix. Building a test bulb today and will report back once I have run through testing at the header pins.

OK, so built a test bulb and confirmed at the header pins that I only get one response across all combinations. So, that leads me to think the board is finally clean and 100%.

All of my diodes check out good and are correctly oriented. All I can figure is a short somewhere...

What's weird, is on almost every single lamp in individual lamp test, I get at least three that light up and they are not in the same row or column...some are, but not all.

This is proving more time consuming to resolve than I had anticipated...

OK, so finally figured this out.

A previous owner had for some reason decided that rather than unplugging the switch/lamp headers when they folded the game up that just cutting all the wires would be a better idea.

When they repaired said wires they managed to cross several: red/yellow, red/orange, white/yellow and white/orange. That was determined by testing continuity from each socket to the header.

Once that was resolved, issues still persisted. Discovered that several wires went from the wrong pin in the header to the wrong lamp socket. Fixed those, and still...problems.

Tested all diodes and they call come out between .4 and .6, good.

Then I notice that some of the wires have been wired to the wrong tab on their lamp socket, thus rendering the diodes useless. Flip wires around on four of them and...BOOM - we finally have a lamp matrix that works.

I will confess that using the old, "pull out the matrix, highlight the fail points, and draw a rectangle around the outer most failures" trick came in quite handy.

Sometimes it's amazing how hard someone will work to ensure a game does NOT function properly!