820-01814 Resistor Measurement

realmacmods

Member
Would anyone that has one of the boards with an irreparably failed SSD (a1990) (820-01814) be willing to take a few resistor measurements for me?

I am looking for
R9080
R9083
R9081
and if C9085 happens to be open or closed.

Ideally this would be on a failed board that is outputting 7.4V on L9081 and/or L9080. Best if the measurements are done with R9083 out of circuit, but I'll take what can get.

Thank you
 

2informaticos

Administrator
Staff member
C9085 is not critical; you can ripp it off.
You can check mentioned resistors and compare with values marked on the schematic.

BTW, the note on the schematic is erroneous; read R9081, instead of R2081!
If these resistors have nominal values and U9080 is good, you should get correct output voltage.
Playing with R9081 and/or R9080, you can adjust the voltage.
 

realmacmods

Member
Thank you for that. Just to clarify what i am trying to achieve since i did not actually mention it.

I do not have a failed one here to measure, but i am trying to get the resistance values of one that has failed in the common way these are now failing. That is the 2.5v supply on L9081 becomes 7.4v and burns out the NAND chips. What i am trying to do is determine what part of that circuit is failing to cause this. I have a strong feeling one of those resistors is the common fault and would like to replace them with higher wattage resistors to prevent the failure on my personal machine.

That is all to say, i am aware what the values are meant to be, and with the circuit in perfect working order i have confirmed that the measured values line up closely to the schematic values, but i would like to know if those values change in the event of the common failure.

Basically trying to do failure analysis, without having a failure to analyze.
 

2informaticos

Administrator
Staff member
U6990 is the same chip.
Output voltage has the same formula, no?
Just recalculate using U9080's resistors value.

You've already have a mention of varying output voltage with R9081.
 
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