PC Power Supply  - Page 1
Forum section: electronics / repair

author: vidarr
author_rank: Frequent Contributor
timestamp: November 15, 2018, 12:36:48 pm
content: This Thermaltake PSU was brand new. It has a warranty, but circumstances (where I live now) prevent me from being able to use it. I fired this thing up maybe 4-5 times. The last time, it popped, sparks came out and then smoke came out. After a year of trying to get the warranty coverage with no luck, I decided to just open it and have a look. I was hoping it was the fuse or something simple. The fuse was fine, but I put a new one in anyway. I inspected everything visually and cannot find anything obvious. The only thing odd is maybe a transformer that looks like it is bulging out (see pic).I checked connections from the plug to the fuse with a DMM and there is continuity between connections. Should I take out the main board and inspect the bottom next?edit: It is Thermaltake Toughpower Grand.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: November 15, 2018, 12:58:04 pm
content: What looks like a transformer in the first pic looks like the magic smoke got out and all over the top, as it looks kind of smokey. As far as looking all over, it is a good plan if you want to try and repair, but if transformer is blown, there is no telling what else it could have taken with it.

author: GeoffreyF
author_rank: Regular Contributor
timestamp: November 15, 2018, 01:23:18 pm
content: I agree tpowell1830 ... it looks like something catastrophic happened. If the mains in your country doesn't match the specifications or switch settings on the back, that could be the genesis of the failure.

author: PKTKS
author_rank: Super Contributor
timestamp: November 15, 2018, 05:35:27 pm
content: Some words of care first..- Don't put your DMM randomly in such devices - there are high voltages spikesand even powered down CAPACITORS WILL HOLD THE CHARGE (for a long period)- Don't power such HIGH POWER device without an ISOLATION TRANSFORMER **AND**a REQUIRED VARIAC to start looking suspects.- Worst case scenario you REMOVE ALL DIODES (which is very time consuming) from the boardand the transistors to properly check them OUT OF CIRCUIT (no voltages no parasitics)The procedures are not trivial - and VOLTAGES are really dangerous when powered on.Take care of yourself and your bench first...Paul

author: vidarr
author_rank: Frequent Contributor
timestamp: November 15, 2018, 07:43:06 pm
content: The white stuff all over the components is that insulation, glue stuff. Is that what you are looking at? I took some better pics of that. When the white spirit came out it didn't go far. It just hovered by the side of the PSU. I don't think it went to Valhalla. But it was kind of dark in the room, so not sure.As for safety, thank you for the reminder. I know about a kid who died working on his PSU and that scares me (I think he shorted a capacitor). I only worked around the plug and fuse so far. The PSU has been sitting un-powered for about three years now. If I take the main board out, I am going to watch as many tutorials I can find first. I got tagged by a capacitor when handling salvaged stuff and it hurt like a hot knife stab. Now, I am borderline paranoid.BTW, did any of you ever see the video of the Chinese kid who was at one of those Chinese internet cafes. He had is phone charger plugged into a 220V outlet. He was moving something around and he stuck the other end of the cord in his mouth. About 2-3 seconds later, the saliva seeped in, and he went from a sitting position to straight as a board in a millisecond. Then, his eyes started lighting up like halogen bulbs. He looked like a X-men character.Thank You!

author: strawberry
author_rank: Super Contributor
timestamp: November 15, 2018, 08:33:05 pm
content: unplug, wait to dischage large capacitors, remove PCB and check for faulty PCB, check for shorts in main switcing devices on mains side. check if stanby IC under copper heatsink is ok and there is no open PCB trace to 400VDC sourceplug in with PCB removed, check if voltage on large capacitors are ~400VDC, check if standby 5V supply voltage is ok

author: vidarr
author_rank: Frequent Contributor
timestamp: November 16, 2018, 01:00:59 am
content: Quote from: strawberry on November 15, 2018, 08:33:05 pmThank you. I will do that tomorrow and Saturday. No doubt I will have some questions along the way. Thanks.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 16, 2018, 11:32:16 am
content: This small transformer can be the xformer coupling signals between the smps ic's and the power mosfets section, unless thermaltake is willing to sell you one you're out of luck.It may exist a clone of this one in other branded psu ... ?

author: Wan Huang Luo
author_rank: Regular Contributor
timestamp: November 16, 2018, 02:22:35 pm
content: Just an aside, how is the power delivery in your area? What voltages do you get at the taps? Do you ever get voltage spikes? Is it possible that the circumstances of your location's mains power had a hand in causing your issue?

author: strawberry
author_rank: Super Contributor
timestamp: November 16, 2018, 03:52:06 pm
content: dont know but this SMPS yellow MOV seems intact