- Jul 4, 2023
- 5
- 0
- 10
Hello everyone reading, long text coming.
My knowledge about electronics is basic but i'll try to explain everything as clear as possible.
I bought a half-height 5.25 drive bay front panel to control 5 fans in my case. It's a Lamptron CU423. First of all, i checked the user manual. It states that the DC Input is: +12V (Standard power interface + 5557-2 D shape * 4 p r). And it also states that both inputs are needed for proper operation.
1) +12 V Standard power interface refers to Molex, is this correct?
2) About "5557-2 D shape * 4 p r" made me doubt a lot. Physically on the PCB it only has a Molex connector and an 8-pin +12 V EPS connector. I guess the D-shape refers to the shape some plastic pin covers have, is this also correct? I assume "4 p r" would stand for 4 power rail or something like that, and i assumed that it needed the EPS 8-pin cable.
I can post a link to the user manual if needed.
The PC and the case fans (currently connected to built-in case fan controller) work normally without the front panel. I connected everything needed to the front panel, then switched the computer on. I did it with the side door opened, inmediately i saw sparks and a small amount of white smoke coming out of the PSU connector where it supplied to the 8-pin EPS cable. Obviously cut electricity supply from the multi-socket adaptor very quickly.
After this, i checked for damage or misfunction on the PSU, cables, motherboard and the new fan controller. Luckily no damage to my components but the fan controller panel was dead.
I can assure that PSU and cables are correctly delivering the +12 V and GND routes, no short-circuit/reverse polarity.
I checked the fan controller panel, i realised that the 8-pin could be reversed. On the PCB it had printed the GND and +12 V text next to the 8-pin connector, but reversed, so the GND text would point to the 4 +12 V pins row, and the opposite, supposing it uses the standard EPS connector pinout.
I informed the seller this whole situation and asked to return the faulty one and then send me a new one. They told to return it, they would check it and if i was right they would send me a new one. I accepted, and yes, it was faulty according to them and sent me a new one.
Here comes the weirdest part of all this process, received the new one but before plugging it i checked the PCB, connectors, etc and same situation, 8-pin connector looks reversed too. I'm certain it's a new one, took pictures of the first panel and comparing with the spare one is another unit. Also, both of them were sealed, i'm pretty sure the seller is being honest and not sendind used/faulty units on purpose.
3) Is there any way to check polarity of pins, ICs and other complex PCB components?
I have a multimeter with basic functions to measure Ohms, Volts, etc and diode mode continuity, which may be useful in this case.
All this looks to me like a faulty design and lack of QA, releasing a bad batch, but i don't have enough knowledge and proof to confirm this.
I can't now but tomorrow i may be able to post pictures, that may be useful for all this hassle.
If someone reachs here and gives any help, clue or suggestion is more than welcome.
My knowledge about electronics is basic but i'll try to explain everything as clear as possible.
I bought a half-height 5.25 drive bay front panel to control 5 fans in my case. It's a Lamptron CU423. First of all, i checked the user manual. It states that the DC Input is: +12V (Standard power interface + 5557-2 D shape * 4 p r). And it also states that both inputs are needed for proper operation.
1) +12 V Standard power interface refers to Molex, is this correct?
2) About "5557-2 D shape * 4 p r" made me doubt a lot. Physically on the PCB it only has a Molex connector and an 8-pin +12 V EPS connector. I guess the D-shape refers to the shape some plastic pin covers have, is this also correct? I assume "4 p r" would stand for 4 power rail or something like that, and i assumed that it needed the EPS 8-pin cable.
I can post a link to the user manual if needed.
The PC and the case fans (currently connected to built-in case fan controller) work normally without the front panel. I connected everything needed to the front panel, then switched the computer on. I did it with the side door opened, inmediately i saw sparks and a small amount of white smoke coming out of the PSU connector where it supplied to the 8-pin EPS cable. Obviously cut electricity supply from the multi-socket adaptor very quickly.
After this, i checked for damage or misfunction on the PSU, cables, motherboard and the new fan controller. Luckily no damage to my components but the fan controller panel was dead.
I can assure that PSU and cables are correctly delivering the +12 V and GND routes, no short-circuit/reverse polarity.
I checked the fan controller panel, i realised that the 8-pin could be reversed. On the PCB it had printed the GND and +12 V text next to the 8-pin connector, but reversed, so the GND text would point to the 4 +12 V pins row, and the opposite, supposing it uses the standard EPS connector pinout.
I informed the seller this whole situation and asked to return the faulty one and then send me a new one. They told to return it, they would check it and if i was right they would send me a new one. I accepted, and yes, it was faulty according to them and sent me a new one.
Here comes the weirdest part of all this process, received the new one but before plugging it i checked the PCB, connectors, etc and same situation, 8-pin connector looks reversed too. I'm certain it's a new one, took pictures of the first panel and comparing with the spare one is another unit. Also, both of them were sealed, i'm pretty sure the seller is being honest and not sendind used/faulty units on purpose.
3) Is there any way to check polarity of pins, ICs and other complex PCB components?
I have a multimeter with basic functions to measure Ohms, Volts, etc and diode mode continuity, which may be useful in this case.
All this looks to me like a faulty design and lack of QA, releasing a bad batch, but i don't have enough knowledge and proof to confirm this.
I can't now but tomorrow i may be able to post pictures, that may be useful for all this hassle.
If someone reachs here and gives any help, clue or suggestion is more than welcome.
Facebook
Twitter
Instagram