Atari 400 Power Board

[AwkwardPotato]

I was recently working on my Atari 400 with the case off, trying to fix some issues. When I tested the machine, without thinking, I used a screwdriver to close the interlock switch for the cartridge door. In the process the screwdriver made contact with the heatsink for the voltage regulator. It made some strange noises and I smelled the faintest trace of smoke. The screwdriver was not in contact with the heatsink for any more than one second, and the Atari appears to be in fully working condition after reassembly. Is it possible that I could have damaged something, and do I need to replace the internal power board?

[ACML]

If you run through several programs and it seems to work, you may have still caused some damage. The smell of smoke means you likely shorted somewhere and enough current caused something to get too hot, just not long enough to fail the part, Atari 400 power boards are ~$15. You might want to buy a spare as this one may not be long for this world. Then again, it could run for years.

Edited January 7, 2017 by ACML

[+tf_hh]

I was recently working on my Atari 400 with the case off, trying to fix some issues. When I tested the machine, without thinking, I used a screwdriver to close the interlock switch for the cartridge door. In the process the screwdriver made contact with the heatsink for the voltage regulator. It made some strange noises and I smelled the faintest trace of smoke. The screwdriver was not in contact with the heatsink for any more than one second, and the Atari appears to be in fully working condition after reassembly. Is it possible that I could have damaged something, and do I need to replace the internal power board?

 

The interlock switches alternating current, the heatsink is connected to DC ground. So you´ve short-circuited AC voltage to ground... it´s you luck that most of the parts in an Atari 400 are good old NMOS chips... CMOS wouldn´t have survive such an attack

 

When the system is running fine, I suggest to inspect all parts carefully. Specially the electrolytic capacitors. The noises... came out of the system or television/monitor? Maybe it was only the 50/60 Hertz buzzing came from the internal speaker or transmitted via RF to the television. Examine the capacitors on the power PCB. If any of the caps are looking like in the pictures below or any fluid is visible around the caps, replace them. Or buy a new power PCB...

 

Jurgen