Identifying Component - SATA Drive Bay

[mrdavies2066]

Hi All,

I'ming trying to repair a pc sata 5.25" drive bay that used to allow me to slide 3.5" drives into the front of my PC. I put a friends old hard drive in my PC to see if I could recover the data for him and there was a smell of burning and it hasn't worked since.

The small circuit inside seems quite simple the sata connection is just straight through from the socket to the drive and there is one small smd chip on the power side. At first i though it was a voltage regulator but not sure that would make sense as device is powered via a molex connector which would provide the 5v and 12v a drive would need.

From what I can make out the chip says 4801 beon47 on but it is a touch chard, I have of course searched the web but cant really find anything on this. Does anyone have any idea of what this might be and if/where I could get a replacement I C?

Its an 8 pin IC, I have uploaded a picture.

Hope someone can help, thanks in advance.

Mark




[image edited by moderator]

 

[Kabelsalat]

Can you elaborate a bit more excactly where this chip is mounted? Inside a drive bay? Is that a variant that is not attached to the rest of the casing? Do you have a bigger picture - one that show the whole case included the placement of the bay you're talking about.

 

[davenn]

At first i though it was a voltage regulator but not sure that would make sense as device is powered via a molex connector which would provide the 5v and 12v a drive would need.

Still suggest it is probably a v-reg .... maybe it takes the 5V rail down to 3.3V or similar?

and has been asked, please confirm .....

is this board on the drive or ..... ?

 

[mrdavies2066]

Hi,

Yes the chip is inside the drive bay on what is the only small pcb inside the unit, I think the new picture i have attached shows better what I mean (old one wasn't ideal sorry).

The second picture shows the casing of the whole unit to give you a better idea its function.

Thanks for your reply.

Mark

 

[73's de Edd]

Sir mrdavies2066 . . . . .


Yer fotie-grafs weren't defining enufs to let me pick out case/ pin indexing for its pin 1.
But looking at the specific hea-vee foil paths used on some of its connections . . . . .

Good probability of it being one of Alfa Omegas’ AO4801 dual FET's.

With that burnt area, see if you now are finding a Drain-Source direct short between pins 1 and 8 or possibly 4 and 5 also.

Its Da-Da Sheet:

https://www.digchip.com/datasheets/parts/datasheet/854/AO4801-pdf.php

73’s de Edd

 

[mrdavies2066]

Hi All,

I was just looking at a pinout for a sata power connector (attached) I had never realised it had a 3.3volt connector, I have done some reading and apparently there are very few drives which use his 3.3v line and if 3.3v is required this is done via the PCB on the disk.

I did somehow miss your post the first time Davenn so to confirm this is not a board from a hard disk but out of the bay itself which houses them.

I am quite a novice when it comes to electronics but think I follow the quote below. Use my continuity tester to check for shorts between pins 1 and 8 and possibly 4 and 5? I can do this when I get in from work and let you know the result. Please let me know if I am misunderstanding.

Good probability of it being one of Alfa Omegas’ AO4801 dual FET's.

With that burnt area, see if you now are finding a Drain-Source direct short between pins 1 and 8 or possibly 4 and 5 also.

Thanks for your help all

 

[mrdavies2066]

Hi All,

I have tested using my continuity tester and believe the components to be connected as per the attached image (there is continuity between these points). The connector labelled as "small white" can be seen on one end of the board and has 5 mins two of which go to a basic toggle switch the other three to a dual colour LED which indicates power and disk access.

Hopefully this helps shed a bit more light on what the IC is? Or confirms De Edd's suggestion that its a dual FET?

Thanks

Mark

 

[73's de Edd]

Sir davies2066 . . . . .

Taking your last forthcoming info and my having “drewed” in your +12 and +5 lines, upwardly from the Drain 1 and Drain 2, to the top of the page.

It then seems that the device perfectly fits the function of performing the +12 and +5 line voltage buss switching.

You have the C1-2 bypassing caps at the top, as well as some possibly being expected on the +12 buss.

You also had some draw in changes down in the R1-2 areas. All of that info and the resistor values could be rechecked.

As drawn, it would be expecting the R1 resistor to be giving adequate gate drive to BOTH gates for turn on, BUT with the lower resistance value of R2 going back to connect to a logic LOW.

Then, If the left R2 side receives a logic HI, both the power supplies then get switched on.

Not being able to see the cavitated chip any closer, does its relative position on the chip suggest whether the 12 or 5 V section seems to be the burnt up / failed side ?

DUAL REFERENCING:



73’s de Edd

 

[Kabelsalat]

I have a couple of thoughts about this after seing the pictures, about what might be the reason - if there is any exept for internal failure of chip or simple overheating because of no working fan.

What in my mind seems to be the biggest possible cause, is that the little circuit board must have touched something metallic, and caused a short. Maybe there have being a harddrive that didn't quite fit in the box, or a screw or mounting bracet have fallen inside.

Second culprit: Voltage spike when disconnecting harddrive. Normally it won't happend, but if using long wires from psu it is theoretically possible.

 

[mrdavies2066]

Hi All,

I purchased a AO4801 which arrived over the weekend and replace the IC and the unit is now fully operational again, the chip only cost me £5 and i'm really glad to have this working again. Thanks for all your help

In answer to your question Edd, yes it was PIN1 (S1) which has 12V connected which was clearly the burnt area of the IC. And Kabelsalat it seems it was just the particular HDD which had failed and caused a short somewhere on the board when I plugged this into a PC PSU directly it overloaded it and made it switch off instantly.

I have attached a picture of my handy work this is only the 2nd time I have used my hot air soldering gun so wasnt feeling too confident but think it went quite well.

 

[davenn]

I purchased a AO4801 which arrived over the weekend and replace the IC and the unit is now fully operational again, the chip only cost me £5 and i'm really glad to have this working again. Thanks for all your help

That's awesome .... well done

 

[73's de Edd]

Sir davies2066 . . . . .


Use a conventional soldering iron with a small tip and put a drop of rosin flux atop a / each pin and then take a perfectly tinned tip and do a quich touch . . . just long enough to see solder melt and reflow. Then move to a pin 180 degrees away and do its reflow. You work that same alternating technique until the last pin is reflowed.
Then, while the pins are still warm , use a cotton Q tip soaked in ethyl or denatured alcohol to clean off all rosin residue. If any areas are resistant, use a bristled acid brush with alcohol and then do a a final Q tip cleaning.
Finally . . . buff and burnish the joints with dry Q tips.
If you have used 60/40 solder . . . . . and following all of this procedure . . . .you will then have observers that query of you . . . Who does yer chrome plating?

73's de Edd

 

[davenn]

Use a conventional soldering iron with a small tip and put a drop of rosin flux atop a / each pin and then take a perfectly tinned tip and do a quich touch . . . just long enough to see solder melt and reflow.

did you miss the fact that he had already put in the new chip and it was working ??

maybe so, as you didn't ackn or congratulate him on his success