Picked up a working Time Fantasy a few weeks ago. It plays and generally works, but the original sound bug it had, has now been joined by a new one, as follows:

PROBLEM 1) Sometimes, at power on, during attract, a 1-second snippet of the background music (Firepower drone) will play and loop repeatedly. If you cycle the audit tables and "reset" the game, the loop changes pitch. If you disconnect the power to the sound board and reconnect it, the loop continues.

When this is occurring, if you start a game there is NO background music... you get most of the standard game sounds, but a few are garbled. After a few minutes (5? 10? 15?) the sound fixes itself. And sometimes at power-on, the issue never even happens!

FIX ATTEMPT: All boards are original and relatively clean. No major hacks. I recapped the power supply and the sound board. The problem did not go away.

PROBLEM 2) After an hour or two or run-time with the recapped boards, now, sometimes, a "heartbuzz" of a 60Hz hum in a pulsating rhythm will appear. It may run steady state for a few minutes at a time. It may glitch for a few moments. If game sounds are being produced, it will interrupt them. If no sounds are being produced (silent attract), you just hear the "heart hum buzz". Sometimes the buzz increases in tempo and pitch and then goes away and all returns to normal. One time all sounds quit entirely.

Either problem may now appear at random, sometimes at the same time. Here is a video...

Bump for the coffee crowd

Separating the issues, I think I'm making progress:

PROBLEM ONE (random BGM on/off sync and effects garbling): So I tested the sound board inputs and all seems fine on that end... funny enough you can really make some neat effects by grounding the input pins in different ways. But everything worked. So I decided to consider the trigger-source side, which is the MPU...

...starting simple, I addressed the connector cable. While the game was stuck in the "out of sync" sound issue, I removed the sound connector from the MPU and replaced it... the problem INSTANTLY went away, and the next switch triggers were normal. Next time the problem surfaced, I reseated the connector and the problem went away again. First time I was able to directly influence the resolution of the issue. So I removed the MPU and lo and behold, a couple suspect cold-soldery looking pins. Reflowed all of them, re-installed, and sounds have been perfect ever since. I've not had time to really push the game much yet, maybe 20 minutes all told, but I think I'm close enough to consider that one resolved, hopefully.

PROBLEM TWO (heart-buzz): Really sounds like 60hz hum, which might indicate AC ripple leaking into the amp circuit. Could be a bad rectifier?

I double-checked my work from recapping the board and discovered the on one of the 3 "main" filter caps C25, the solder did not fully flow to the top + trace as expected. This trace directly connects to the amp. I fixed the connection saw improvement: overall "background hum" was basically eliminated, so standby / attract mode is utterly silent now. However, the heartbuzz still appears from time to time, but not as bad as before.

While I wonder if the rectifier is bad (perhaps my poor C25 connection weakened it?), OTOH its output voltage seems stable enough. Not sure if the rectifier is a culprit, or one of the new filter caps is defective....?

So having played several games since, it seems reflowing the MPU connector indeed fixed the incorrect / intermittent sound issue!

The pulsing heartbeat remains. Similar to my video above, but now apparently constrained to power-on, and it will subside after a couple minutes... after which you'll hear the tempo increase and the pitch decrease until it stops completely. It's as if the caps are charging up or something, very odd. If you leave the game off for a short time, the problem doesn't recurr. If it's off for a while, it's as if it has to charge up again....

No, I haven't attempted to solve it since the last post... been working and playing on other games, plus other life distractions... the "heartbuzz" nuisance has actually been minimal the last few times I've played TF. It clears up within 30 seconds of turning the game on and never comes back while on, and we've had it on for several 30+ min stretches.

For what it's worth a friend of mine thinks it might be the rectifier, but I'm less convinced. I mean if it were the rectifier I'd think it should almost never work at all...? But once/if I get some time I might replace it anyway just for gits and shiggles and see what happens.

The goofy sounds issue has never come back since I reflowed the MPU header.

What problems are you having?