Speak & Spell Troubleshooting

[Banquo]

Hi all, I recently came across an original model Speak & Spell with the raised letters. It's in very nice condition but it's not working. I put in fresh batteries but it won't come on, however if I hold the On button down it makes crackling noises and random letters light up on the display. I opened it up and didn't see any obvious problems like corrosion or broken connections so I'm guessing one of the components may be bad, maybe in the power supply. Has anyone ever seen this issue before?

 

Edited February 13, 2016 by Banquo

[7800fan]

If you have pinout of the power supply and a meter, you can check the pins. If all the outputs are at expected level while the unit is powered off and it refuses to power on, the issue could be fried CPU. If the power supply module doesn't have the right voltage, have it checked for dead caps, shorted transistor, or burned resistors.

[Banquo]

Thanks, I haven't been able to find that info yet but there is voltage present, just not sure if it is correct. However I think I stumbled onto something. My board has a small potentiometer on it and I turned it a little just to see if anything happened, and there was a noticeable difference when I held the On button. Instead of the crackling noises it sounded more like tones, but still very broken and also instead of random flashes all over the VFD screen actual letters were briefly appearing. It still won't come on but I'm going to try cleaning the pot with deoxit tomorrow.

Edited February 14, 2016 by Banquo

[Banquo]

Success. After I cleaned the pot it came to life and is working perfectly now.