Member Avatar for i0r

Hi! am new here. please help..

my powersupply just got blown. the fuse blew up. Now, am having a doubt on wether to check the motherboard with new power supply becoz am afraid that the if the motherboard is already defective .. it might damaged the new power supply..

What is the possibiity of a SHORTED/DEFECTIVE MOTHERBOARD blowing up the POWERSUPPLY?

pls help. juz need to be sure bfore installing a new power supply..


Thanks..=)

  • 2 Contributors
  • 3 Replies
  • 863 Views
  • 1 Day Discussion Span
  • Latest Post Latest Post by fren

Dani AI

Generated

Short answer: rare but possible. ’s concern is reasonable and ’s practical point about bad PSUs being the usual culprit is correct — most of the time a failing power supply fries a motherboard, not the other way around. Still, a board with a hard short can blow a new PSU’s protection or its mains fuse if the PSU has weak or faulty protection circuits.

How a motherboard can stress a PSU: a direct short on a power rail (failed VRM MOSFETs, shorted electrolytic capacitors, solder bridges, conductive debris, or a shorted connector) pulls heavy current and forces the PSU to shut down or, in extreme cases, fail. Conversely, if the PSU’s mains (AC) fuse already blew while the PSU was connected to AC and not the board, that usually points to an internal PSU primary failure rather than a motherboard-caused short.

A safe testing workflow (recommended order):

  • Perform a careful visual inspection for burn marks, swollen/leaking caps, scorched traces or strong burnt smell.
  • Remove the board from the case and strip all cards, drives and front-panel connectors.
  • With the ATX connector unplugged, check DC rail resistance from the main connector wires (typical colors: yellow = +12V, red = +5V, orange = +3.3V) to any ground (black). Very low resistance (roughly under an ohm) suggests a short.
  • If no obvious short, power-up tests should be done with either a known-good spare PSU, an inexpensive old PSU, or a bench supply with current limiting. Use a PSU-tester or limit the test time and watch for smoke/fuses.
  • If a short is found or heavy damage is visible, repair or board replacement is safer than risking a new high-quality PSU.

Safety note: mains work and power-on tests carry risk. If uncertainty exists, have the board checked by a repair shop.

Recommended Answers

All 3 Replies

Member Avatar for fren

In my knowledge and based on my experience, a faulty power supply may damage a good motherboard but not a bad motherboard damage a good power supply.

In your case, you can safely test your motherboard with a new power supply.

Member Avatar for i0r

Thank you so much for your help. I juz wanted to be sure...am not an electronic guy but i was just thinking that if some positive and negative lines contacted within the motherboard then the power supply will be shorted =)...


maybe its a case to case basis, i mean the extent of the damage.. it wont be practical to test a burned motherboard with powersupply.. but with no indication of burn.. then i'll take your help..according to your experience as you said..

Thank you so much..:)

Member Avatar for fren

Since all the electronic components on the motherboard were all soldered. Therefore, no short connection will occur on it unless you accidentally made a short between them. The burnt mark found on the motherboard is mostly created by a spark from a loose connection.

And I think a short or fault connection from your computer came from the primary circuit of your power supply. Then the secondary circuit is automatically tripped off. So, no output voltage from your power supply is delivered to your motherboard.

You cannot test your motherboard without power supply installed. Charge to experience (sacrifice) or test your motherboard to a shop.

Okay, wait for some other ideas.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.