Editing Atari TT General Maintenance (section)

== PSU Maintenance ==

The TT030 PSU is a switch-mode power supply providing +5V, +12V, and −12V rails. It is physically larger and more complex than the standard ST/STe PSU.

=== Voltage Verification ===

After any PSU maintenance, verify output voltages under load:

<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable styled-table"
! Rail !! Nominal !! Acceptable Range
|-
| +5V || 5.00V || 4.85V – 5.15V
|-
| +12V || 12.00V || 11.50V – 12.50V
|-
| −12V || −12.00V || −11.50V – −12.50V
|}

* Measure at the motherboard power connector pins, not at the PSU output, to account for cable voltage drop.
* If the +5V rail drifts high (above 5.2V), the PSU voltage regulator may need adjustment or the feedback circuit capacitors may be degraded.

=== Fan Maintenance ===

The TT030 has one or two cooling fans (early models have two, later models one):

* Clean fan blades with compressed air.
* Lubricate sleeve-bearing fans with a drop of light machine oil on the bearing (accessible by peeling back the label on the fan hub).
* Replace the fan if it produces audible bearing noise or fails to spin freely. Use a 12V DC fan of the same dimensions. Ball-bearing replacements are preferable for longevity.