SEGA Mega Drive AC Mains Adaptor (1602-05) Refurbishment:
Model No: 1602-05
Input: 240V 50Hz
Output: 10v DC 1.2A
Polarity: Center Negative
To open these SEGA power bricks up you will need a 4mm HEX driver.
However finding one that can open these can be quite problematic due to the depth of the holes and them only being 7mm in diameter:
I searched through quite a fair few tools before I found one that would be suitable to open these.
I recommend using a Wera Kraftform Micro Series 2069 05118120001 Nutdriver HEX 4.0 x 60mm
Now that it is opened up you need to de-solder the two points circled below:
Which separates the small PCB from the transformer leaving you with:
You can immediately see the capacitor has been leaking and that the power cable that is connected at C1 is frayed a little. This is the third SEGA mains adaptor that I have opened up and this has been the case in all of them so far.
While it is not necessary I de-solder all components from this small PCB as I intend to replace everything:
Original 1602-05 Component List:
- 1x 3300μF 16v Capacitor
- 4x 30D2 Switching Diode
- 1x 390Ω Resistor
WARNING!
The US 1602 AC Mains Adaptor uses slightly different components:
- 1x 3300μF 16v Capacitor
- 4x Switching Diode (unable to confirm type)
- 1x 750Ω Resistor
Here is the reverse of the PCB for anyone that is interested:
NOTE:
As mentioned previously it is not necessary to replace everything. The only thing you really need to replace is the single capacitor unless the other components have burnt out in which case the mains adaptor would not be working to begin with.
30D2 Switching Diodes are no longer being manufactured and are very difficult to find. These four diodes are performing the AC to DC conversion which is known as a “full-wave bridge rectifier”.
A suitable modern replacement for these are 1N5408 Switching Diodes.
For the 390Ω resistor I replaced it with a modern and more efficient 390Ω 1W Metal Oxide Resistor.
After cleaning up the PCB and slightly cutting back the frayed wire ends I re-assembled the small power PCB with the new components:
OPTIONAL STEP:
If your transformer is showing signs of rust you can also remove that by de-soldering it from the plug connectors circled below:
You can now easily use some rust removal jell on it if it is really bad or just lightly linish away the rust:
If you do this remember to replace the clear plastic piece to the bottom if it is present or just wrap it in Kapton Tape if it is not. And ensure you re-connect the polarity correctly!
TESTING:
I tested this power adaptor before and afterwards within my limited means and these were the results:
BEFORE:
- DC Voltage (Unloaded): 13.30v
- DC Voltage (Mega Drive Load): 10.90v
- AMPS (Mega Drive Load): 0.8a
AFTER:
- DC Voltage (Unloaded): 13.40v
- DC Voltage (Mega Drive Load): 11.00v
- AMPS (Mega Drive Load): 0.8a
Not really any change for the better or worse.
CONCLUSION:
It is well worth opening up your SEGA AC Mains Adaptor to change the 3300uf 16v capacitor that will be at the end of its life and sort out any frayed power cord wire ends, but everything else you can just leave alone unless there is a problem.