Originally Posted by mike386
Can I connect the power supply from a Tivo HD to a original Series 3 (model with time display on front)? I want to test the power supply in the S3 to see if that is why it is stuck on the powering up screen, but the closest model I have is a Tivo HD.
That's not the best way to do it (best way is with voltmeter or oscilloscope), but yes, the pinout for the motherboard plug is the same except for the white or gray wire on the TCD648250 supply.
That wire, at, as I recall, +7.5 V, is for the OLED display and therefore not necessary on the 652/658 motherboards.
If you connect a 648 supply with that extra wire to a 652 or 658 motherboard, I do not know if it will come into contact with anything or not, and therefore you should not do that, due to the possibility of burning things our and starting fires.
However, temporarily, for test purposes only, you can run the 648 motherboard with either model of the 652/658 power supply.
In addition to the #10 Torx bit silver-colored screws holding the power supply circuit board down to the chassis stand-offs, there is a number #8 or #9 Torx screw which is smaller around, longer, and darker, and it screws in from the outside into the plastic at the top of the AC power cord jack.
When you install the test supply, use all the screws you took out of that TiVo which will be under test to secure it to the chassis and back panel--no short-cuts, no "Oh, 3 or 4 will be enough for right now".
And remember the number 1 rule:
ALWAYS KNOW WHERE BOTH ENDS OF THE TIVO POWER CORD ARE AT ALL TIMES!