old quantm fireball drives power problems

[maxword5]

salam alekm
i have hdds quantm with nearly same problem when i give it power just the led is flshing and dosent spin up the voltage that reaches to motor is 3 volt in some and 7 in one i measured it from good one its 8 volt what makes voltage drop in pcb?

[hddlab]

Did you try to swap PCB?

[hddguy]

The quantum fireballs are well known for electrical faults, particularly the Fireball LCT family. PCB replacement sounds like the best thing to do.

[maxword5]

salam alekm

i already repaired a pcb that had burned trans but the other that has no burn has no errors with trans it seems somthing in power circuit please any one has expirence in these tell me