Re: Fun with fixing I-Micro power supplies
Can it do labeled power now?
Can it do labeled power now?
-
Less jewellery, more gold into electrotech industry!
Half of the computer problems is caused by bad contacts 
Exclusive caps, meters and more!Hardware Insights - power supply reviews and more! -
Main rig:
Gigabyte B75M-D3H
Core i5-3470 3.60GHz
Gigabyte Geforce GTX650 1GB GDDR5
16GB DDR3-1600
Samsung SH-224AB DVD-RW
FSP Bluestorm II 500W (recapped)
120GB ADATA + 2x Seagate Barracuda ES.2 ST31000340NS 1TB
Delux MG760 case
Comment
-
Re: Fun with fixing I-Micro power supplies
Are you kidding? Of course it can. Didn't you check the label on the power supply case? It has UL and CE certification, along with certifiction from a couple of other certification agencies.Attached Filesif you find these attachements useful please consider making a small donation to the site
Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)Comment
-
-
Re: Fun with fixing I-Micro power supplies
that certifies the case, not the contents.
Comment
-
Last edited by Dan81; 03-28-2015, 09:17 AM.Main rig:
Gigabyte B75M-D3H
Core i5-3470 3.60GHz
Gigabyte Geforce GTX650 1GB GDDR5
16GB DDR3-1600
Samsung SH-224AB DVD-RW
FSP Bluestorm II 500W (recapped)
120GB ADATA + 2x Seagate Barracuda ES.2 ST31000340NS 1TB
Delux MG760 case
Comment
-
Re: Fun with fixing I-Micro power supplies
Back to the story of the last I-Micro I fixed. I was ready to test, hooked it to a Pentium 3 mother board, and watched the fireworks. I repaired it (see previous posts). It ran the Pentium board fine, but after a few hours it quit. I decided to give it the "Uniqu3" modification. I removed the output diodes and installed a Shottky 3045 on the 3.3 volt rail, a Shottky 3045 on the 4 volt rail, and a MBR Shottky 20100 on the 12 volt rail. To improve the input side I installed a pair of C2625 switching transistors. Applied power using the Pentium 3 Biostar M6VLQ motherboard as a load. Ran it many hours with no trouble. At last it is fixed.....I thought.
With boldness, I attached it to a Pentium 4 class motherboard. Pushed PS_on switch.....BANG, fizz, and a small fireball! Both switching transistors shorted, the C945 driver transistors were bad, and the 7500 pwm chip was shorted. Also a couple of bad diodes, and the resistors in one of the switchers had blown resistors. I replaced the switching transistors with 13007. I also replaced the two electrolytic capacitors in the switching transistor circuits. Replaced the driver transformer just in case it shorted. Attached it to the Pentium 3 motherboard and once again it came to life.
Some interesting measurements: with no hard drive attached, the 5V rail reads 5.12 volts and the 12V rail reads 12.58 volts. When I attach the hard drive, a 40 gig Maxtor ATA100, the 5V rail reads 5.01 volts and the 12V rail reads 12.48 volts. Seems to me to be a rather large voltage drop when adding only a hard drive. I think that trying the Pentium 4 motherboard would again farkle its tra-la-la, so I am reluctant to put a heavier load on this 400 watt power supply.
So what do you think?Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)Comment
-
Re: Fun with fixing I-Micro power supplies
Wow, it exploded just connecting it to a P4 board?! What else was it powering?
What else did you have hooked up to it? Was this with the P3 board or just a paperclip? I think it's very normal for the 12V to read very high with low 12V load on half bridge units. Since they were usually designed with low end ultra fast diodes, the schottky seems to bring the "low load" voltage up very high. As we know, these designs like 5V. It seems like the extra 5V from the hdd "levelled" it out a little bit. I'm just guessing. I bet if it were to power a 12V heavy machine, the 12V would drop to something around ~12.3VSome interesting measurements: with no hard drive attached, the 5V rail reads 5.12 volts and the 12V rail reads 12.58 volts. When I attach the hard drive, a 40 gig Maxtor ATA100, the 5V rail reads 5.01 volts and the 12V rail reads 12.48 volts. Seems to me to be a rather large voltage drop when adding only a hard drive.
I don't blame you. Maybe try a different board? I'm not sure why it would power the P3 fine and not the P4 system. It looks beefy enough especially with the new silicon you put in it.I think that trying the Pentium 4 motherboard would again farkle its tra-la-la, so I am reluctant to put a heavier load on this 400 watt power supply.Comment
-
Re: Fun with fixing I-Micro power supplies
At present, the power supply is attached to a Pentium 3 Biostar M6VLQ motherboard with onboard video, 512 meg of PC100 memory, PS2 keyboard, PS2 mouse, and 40 gig Maxtor ATA100 hard drive. I don't consider this to be a very heavy load! The voltage measurements were made using this motherboard and hard drive as the load.
The board that blew it up turns out was not Pentium 4. It is a pullout motherboard from a EMachine, a K7MNF-64 made by FIC. It has a Sempron socket 462 AMD K7 2 gig processor (SDA3000DUT4D) and 1.256 gig memory. I am using the onboard video. It also had PS2 keyboard, PS2 mouse, and hard drive attached. I tried using one of the other rebuilt IMicro power supplies on it.....worked OK for several hours. The IMicro that worked had a much larger switching transformer.
The EMachine board was a pullout with some bulging capacitors. I had already replaced capacitors and checked out with blue esr meter. I tried using several of my repaired power supplies on this motherboard, and all worked fine. With a good power supply this motherboard does fine.
I am beginning to think that the small switching transformer is the culprit. It looked like the same size transformer that was in the power supply Uniqu3 rebuilt (from pictures he posted). I would have thought it would be capable of handling the AMD K7 processor mother board. I guess that the motherboard needs more than a 400 watt IMicro power supply.........Last edited by everell; 08-09-2015, 04:59 AM.Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)Comment
-
Re: Fun with fixing I-Micro power supplies
That systems takes less than 100 watts so it seems this is really top class PSU lolLess jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts
Exclusive caps, meters and more!Hardware Insights - power supply reviews and more!Comment
-
Re: Fun with fixing I-Micro power supplies
Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts
Exclusive caps, meters and more!Hardware Insights - power supply reviews and more!Comment
-
Re: Fun with fixing I-Micro power supplies
Sarcasm??? This whole thread has been nothing but sarcasm. Although it has been fun playing with the IMicro power supplies, I hope no one seriously thinks I like them. I don't even trust any of them to be permanently installed in a computer. i have enjoyed the feedback everyone has given. I also enjoyed the fireworks from those IMicros that didn't make it. And the sarcasm and jokes have been great.
My favorite power supply is the Bestec ATX-250 12E with DM311 mod, and a few other mods. I have one in the computer I am running now. It has been running for some time, and no 5vsb overvoltage problems.Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)Comment
-
Re: Fun with fixing I-Micro power supplies
I'd say it was waste of time since you have about hundred units which are 10times better any day of the week waiting to be processed, but that's me…don't really find any fun in making PoS just better PoS and if you want to see it burn, you don't need to do any modifications on that do you
Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts
Exclusive caps, meters and more!Hardware Insights - power supply reviews and more!Comment
-
Re: Fun with fixing I-Micro power supplies
This is the first time I saw this thread and I found it very interesting. I understand the sometimes you do things just because you can mentality. It is like mountain climbing, there is no point to it other than some people seem to enjoy it.Comment
-
Re: Fun with fixing I-Micro power supplies
Climbing is excercise at least…Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts
Exclusive caps, meters and more!Hardware Insights - power supply reviews and more!Comment
-
Re: Fun with fixing I-Micro power supplies
I don't think this one is complete junk, at least it has a 35 transformer. We've seen much more gutless units pump out 250W DC no problem. This one may have a defect, or maybe something is arcing. I have a Sun Pro that looks very similar to this one, and it could power a Prescott and an OC'd 9800GT at full load after the 12V had two schottky in parallel. The unit got really hot but ran for hours no problem.Comment
-
Re: Fun with fixing I-Micro power supplies
I think the transformer is a 33Old proverb say.........If you shoot at nothing, you will hit nothing (George Henry 10-14-11)Comment
-
Re: Fun with fixing I-Micro power supplies
Yeah another reason not to use these gutless wonders, the efficiency must be in some 60 % region.
Decent unit will pay itself on electricity in time. Man srsly, manufacturers are competing in 80 PLUS Titanium (around 95 % peak), there are 550W Titanium units to come on market and you waste your time with this? 
Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts
Exclusive caps, meters and more!Hardware Insights - power supply reviews and more!Comment
-
Re: Fun with fixing I-Micro power supplies
Because man, a Titanium PSU is expensive, and I get these units for free. Just because I was testing it with that system doesn't mean that's the one it was going to be powering. I use a Precott + OCd 9800GT to stress test PSUs. If it can handle that power hungry system for hours, then I know it can safely power a Core 2/Core i3 system with a lower end video card no problem. I have plenty of 80 Plus units in use, I just also have a lot of cheaper units I got for free that I use.Comment
-
Re: Fun with fixing I-Micro power supplies
If you count the manpower and material plus that poor efficiency it will become very expensive in the long term no matter how much you payed or did nto pay) for that.
On the other hand 80 PLUS Gold certified Seasonic SSP-350GT or similar quite cheap unit has 100% quality internals and you will definitelly notice 25-30 % higher efficiency as long as you don't steal electricity…Less jewellery, more gold into electrotech industry! Half of the computer problems is caused by bad contacts
Exclusive caps, meters and more!Hardware Insights - power supply reviews and more!Comment
-
Hi,
Back after a long hiatus with some old power supplies that need repairing. I've recently picked up a couple of 386SX systems, two 486DX systems, a SiliconGraphics Indy and an iMac G3 that either have verified leaking capacitors in their power supplies, or are likely to in the near future. For the sake of simplicity, instead of tackling all at once, I'm starting with the 386's and one of the 486's.
The 386's power supplies are Seasonic SS4040A's, with caps that are visibly leaking, and 9 replacement caps per unit are required. Most appear to be from the Rubycon... -
Hi everyone.
Recently scored a dead amp from a mackie srm1801 subwoofer and after fixing it, now I'm thinking about a home cinema/party subwoofer project.
Most likely I will use a 15" JBL woofer, which I already have and a diy box.
After reading the mackie user manual, I noticed that it has a 40hz HPF (labeled as "36Hz BUTTERWORTH HPF" in the SM) to protect the speaker from low frequencies. Indeed this seems to be good idea for the intended usage - professional music subwoofer, but bad for movies, where one would expect to "feel" the SUBwoofer.... -
I have acquired a used Dick Smith Q-1760 power supply - although the OEM is Manson Industrial
It has at least one problem.
The voltage control potentiometer VR2, 50K is faulty - going high resistance / open circuit in the CCW end and leading to the output voltage jumping around.
I have already ordered a replacement potentiometer, so that's not an issue.
Now, I want to replace all three electrolytics on the PCB as they are CapXon and I don't trust them so much, I will replace them with something better while I've got the thing apart anyway.
All are CapXon... -
I have two of these mini PCs: TrigKey S5 with Ryzen 5700U, 32GB RAM, 1TB NVMe SSD, Win11 Pro. They work very well for most uses. They are powered by a HuntKey 19V 4.74A brick with a standard DC5525 tip, which feels decently heavy.
When the brick is connected to the system through a 1 meter DC female-male extension cord (18AWG so decently thick), the system will black screen and reboot when multiple objects are sliced simultaneously in PrusaSlicer. One object is OK. Literally any other activity on the PC is OK. It is just this one specific thing that causes a reboot. I tried running... -
Hello
I have a big problem and that is that in some cases when repairing active pfc power supplies I cannot work with a test lamp. I can only get help with 5 volts standby and for starting and starting I have to work without a lamp and this way there is a possibility of parts exploding and other parts being added.
Sometimes with a multimeter test the problems can be reduced to some extent, but I had several cases that had to be tested on and online and recently two varistors exploded. They had terrible resistance because the power supplies were over 800 watts.
Is there a way...
Comment