Re: Challenging 2465 PS repair


Ozan
 


My weird mind has a question: the service manual says to use 2 pcs of 2 ohm
resistors to load the 5VD output, however, the manual does not say whether
they should be in series or parallel?
I put them in parallel, because if they needed something like 4 Ohm, they just
would have used a 3.9 Ohm resistor.
--
Hi Leo,
In 2465 schematic 5VD has a 5A fuse so 2//2=1ohm would be too small (too much current for the supply). Interestingly 2467B has a similar PSU and the load instructions say: "TEST LOAD. Connect a 2-ohm, 25 watt resistor (Tektronix part number 308-0205-00) from the +5 VD pins of J303 and J232 (on the Inverter Board) to ground.". Almost the same instructions as 2465 but "a 2-ohm" instead of "two 2-ohm".

A single 2-ohm might be intended if this is a typo; however, it is better to start with two 2-ohms in series to be safe,
Ozan

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