AtariTempest
Next steps
2020 Feb 6
- Used DeOxit and a fiberglass pen to clean main PCB connections
- +5VDC on PCB is at around 4.7V
- ARII bottlecap transistor is very, very hot.
- Ordered some replacement 2N3055 transistors
2020 Jan 20
- Checking out the power brick again
- Considered soldering wires to the fuse block terminals
- Discovered that the fuse in F2 is loose, pinched the prongs of the holder
- Red probe J5 Pin 1 - 14.67VDC steady! (fixed I think)
- Testing ARII
- 36VAC test points - 37.18VAC
- -22VDC test point - -24.95VDC
- +22VDC test point - 24.88VDC
- 12VDC test point - 12.13VDC
- -5VDC test point - -14VDC - problematic? needs testing under load?
- +10.3VDC UNR test point - 14VDC - problematic?
- Checked VDC on C1 positive lead - 4.78VDC
- Adjusted to 5.01VDC using pot
- Testing +5VDC on PCB
- 4.67VDC - seems too low, connections need cleaning? harness damaged?
2020 Jan 17
- Attempting to test the Atari power brick
- Schematics: https://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Tempest/Tempest_DP-190-2nd-01B.pdf
- Fluke 115 meter set to DC V
- Black probe in pin 5 of J5
- Red probe J5 Pin 1 - 0.3VDC fluctuating - this seems problematic
- Red probe J5 Pin 2 - 14.67VDC steady
- Red probe J5 Pin 3 - 14.67VDC steady
- Meter set to AC V
- Black probe J5 Pin 6, Red probe J5 Pin 7 - 37.11 VAC steady
- Black probe J5 Pin 8, Red probe J5 Pin 9 - 6.433 VAC steady
- Black probe J5 Pin 10, Red probe J5 Pin 13 - 49.97 VAC steady
- Continuity in F2 fuse holder seems inconsistent - maybe replace fuse block and fuses
- Here's a template for printing a new fuse block cover