Unable to get recapped Performa 550 to power on

[nlh101]

Hello all!

I have a Performa 550 with the logic board and analog board professionally recapped by Amiga of Rochester. AoR tested both the logic and analog boards in multiple different systems based on the same system architecture, and the boards worked perfectly in all of the systems he tested it with.

However, when I put the boards into my Performa 550, nothing happens when pressing the soft power button on my ADB keyboard. We've gone through all of the troubleshooting that we can do remotely, but still, nothing happens when we attempt to power on. There's no burned spots on the board, and the backplane connectors appear to be clean. My only remaining possible issue is that something is messing with the bus.

Is there anything I should try when troubleshooting this unusual issue?

Thank you!

 

[wottle]

Are you sure the ADB keyboard is good? I believe you can short pin the PWR pin to ground to get it to boot without a working ADB keyboard with power button (http://www.interfacebus.com/ADB_Pinout.html).

Also, it's usually not needed after a recap, but I've had some 550, Color Classic, MacTVs that refuse to power on right away after being powered off for a while. Plugging it in and flipping the power switch to the on position overnight has worked on multiple machines (although that symptoms always gone away after I recapped the analog board).

Also, are you sure the analog board was recapped? The hot glue (particularly around that big cap) looks old to me.

 

[nlh101]

• I know the ADB keyboard is good; it works as intended on my Power Mac G3 B&W.
• I already tried the 24-hour power on, and there was unfortunately no difference.
• The board was definitely recapped, it is new hot glue. Every capacitor has been replaced too!

 

[jajan547]

I'll bet the edge connector has dirt or debris in it I know it may sound crazy but blow it out carefully. I had a similar issue on my Color Classic and this solved my issue. Also inspect the edge connector for any damage to the pins.

 

[nlh101]

I'll definitely clean the edge connector. I also have a lead from a staff member on 68kMLA who might have a 550 chassis harness that I can test with to confirm my hypothesis.

 

[jajan547]

Try that first, if not I think I have a spare chassis laying around.

 

[nlh101]

I got it to power on after cleaning the chassis harness! However, now I'm experiencing a few weird issues with the machine.

The power light on the front comes on, and initially the system chimed and showed the flashing question mark, but now the system doesn't chime anymore and the screen isn't consistently powering on.

Additionally, I tried to plug in my BlueSCSI V1 with the quick-insert adapter that came with the machine, but either the BlueSCSI doesn't power on, or the machine doesn't power on with the BlueSCSI plugged in.

Anything I should start with?

 

[jajan547]

I got it to power on after cleaning the chassis harness! However, now I'm experiencing a few weird issues with the machine.

The power light on the front comes on, and initially the system chimed and showed the flashing question mark, but now the system doesn't chime anymore and the screen isn't consistently powering on.

Additionally, I tried to plug in my BlueSCSI V1 with the quick-insert adapter that came with the machine, but either the BlueSCSI doesn't power on, or the machine doesn't power on with the BlueSCSI plugged in.

Anything I should start with?

I know this may sound crazy but [CAREFULLY] reflow the CUDA chip with fresh solder and flux. If this doesn't fix your issue which it may not, leave the system plugged in with the power switch on for say 20 minutes. Come back to the machine and flip the switch off then back on and connect your keyboard and try to soft power it on like you normally would. These specific machines can be quite finicky with the power circuitry.