CD32 woes

[Secret Vampire]

I picked up a CD32 at a car boot the other week for £8.

No PSU or accessories of course, and there's a crack in the CD lid, and it has seen considerable moisture judging by the rust on the shielding, but i figured it's got to be worth what i paid for parts.

Before even contemplating powering it up I popped it open, cleaned the rusty residue from the PCB and wire brushed the worst of it from the metalwork. The board looks pretty good considering.

So, bodge an old AT power supply into the power connector, power it on, and no blue smoke, nothing gets hot. Reattach the cd drive and front panel slap in an old AF coverdisk, and frankly to my amazement, it boots. I wish all my other machines displayed that level of reliability
But what's this? mouse clicks/button presses register but I get no movement. I can get some kind of response if I thrash the joystick around but hoping the pointer makes it to where you want it through random movement is not really practical. With a keyboard hooked up I can use that to control the pointer, but without mouse or joystick control it's not much use. I tried with at least 4 different mice, I don't think they can all be broken.

Off to the schematics, I'm getting +5v on the mouse port where I should, and continuity through to the inputs of U34, all the 4k7 pullup resistors test ok, and we have continuity between pin 13 of u34 and pin 20 of Lisa. So at this point the finger of blame is pointing firmly at U34 (74LS166).

I thought before i break out the hot air station I'd check with the gurus here whether there was anything stupid and obvious I had missed.

[xArtx]

Only stupid obvious thing I can think is if you put the mouse in port 1 toward the back of the machine.

[FOL]

I had this issue, R352 was burnt up. Maybe yours is the same.