[SOLVED] Identify TVS Diode and Best Way to Test 2.5 SATA

[Lee_Bee]

Hi there,

Can anyone help me identify the TVS diode on my Hitachi 2.5 SATA PCB? And also tell me the best way to test it?Thank you in advance.

https://imgur.com/a/M4kApOi

View: https://imgur.com/a/M4kApOi

 

[fzabkar]

Measure the resistances of the marked components:

http://www.users.on.net/~fzabkar/HDD/0A90269/TVS_diode_fuse.jpg

See my FAQ for more info.

TVS Diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86

 

[Lee_Bee]

Measure the resistances of the marked components:

http://www.users.on.net/~fzabkar/HDD/0A90269/TVS_diode_fuse.jpg

See my FAQ for more info.

TVS Diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86

Thank you. I will give this a try tomorrow.

 

[Lee_Bee]

Measure the resistances of the marked components:

http://www.users.on.net/~fzabkar/HDD/0A90269/TVS_diode_fuse.jpg

See my FAQ for more info.

TVS Diode FAQ:
http://www.hddoracle.com/viewtopic.php?f=100&t=86

Thank you so much for your help so far. After testing the diodes and fuse it appears to be the fuse that has blown - when first turned on the multimeter I have has 1 on the display all the time until I tested the diodes and it changed, the readingnever changed when I tested the fuse. From reading your FAQ it appears that I can replace this with a piece of wire or blob of solder - the drive will not be going back in the machine where it blew, it will only be going in an external enclosure so that I can retrieve the data. Do you have any recommendations as to the type of wire or power of the soldering iron I should use?

 

[fzabkar]

You need to be very sure that there are no other problems. What are your diode readings? You say that you "tested the diodes and it changed" ... to what?

The best solution would be to replace the fuse, although I understand that this is not a practical DIY solution for most people, especially as you are asking about soldering irons. If you are happy to accept the risks, and if the diode resistances are OK, then any low wattage iron should be sufficient.

 

[Lee_Bee]

You need to be very sure that there are no other problems. What are your diode readings? You say that you "tested the diodes and it changed" ... to what?

The best solution would be to replace the fuse, although I understand that this is not a practical DIY solution for most people, especially as you are asking about soldering irons. If you are happy to accept the risks, and if the diode resistances are OK, then any low wattage iron should be sufficient.
[/QUOTEa

You need to be very sure that there are no other problems. What are your diode readings? You say that you "tested the diodes and it changed" ... to what?

The best solution would be to replace the fuse, although I understand that this is not a practical DIY solution for most people, especially as you are asking about soldering irons. If you are happy to accept the risks, and if the diode resistances are OK, then any low wattage iron should be sufficient.

Apologies, I should have put the readings in my previous post. The two on the right are 96.6 (top one in picture) & 97.8 (larger one just below it). The very tiny one over on the left is 00.4. I think I would be able to replace the fuse if necessary, but, I thought it would be ok just to form a bridge where the fuse is to enable me to fire the drive up and pull the data off in an external enclosure. Thank you for any help with this.

 

[fzabkar]

The diodes appear to be OK. I'm not sure if 100 ohms is OK for the rest of the circuit, though.

There are two inductors. One is marked "AG1" and is located below the TLS2601 motor controller IC. The other is above this IC. Measure the resistance between each inductor and a screw hole.

 

[Lee_Bee]

The diodes appear to be OK. I'm not sure if 100 ohms is OK for the rest of the circuit, though.

There are two inductors. One is marked "AG1" and is located below the TLS2601 motor controller IC. The other is above this IC. Measure the resistance between each inductor and a screw hole.

AG1 to screw hole 158.7 the other I can't seem to get a reading to the screw hole.

 

[fzabkar]

Seems OK to me. I still don't like the 100 ohm reading, but without a good board for comparison I don't know if this is OK.

Be aware that you must not damage the 8-pin chip at the bottom left corner. This chip must be transferred to a replacement PCB, if you decide to go that way.

 

[Lee_Bee]

Seems OK to me. I still don't like the 100 ohm reading, but without a good board for comparison I don't know if this is OK.

Be aware that you must not damage the 8-pin chip at the bottom left corner. This chip must be transferred to a replacement PCB, if you decide to go that way.

Thank you. I will attempt to bridge the fuse - what gauge wire would be suitable? Out of curiosity, what reading would you expect on the TVS?

 

[fzabkar]

Just flow a blob of solder over the fuse. The voltage at the TVS diode should be 5V.

 

[Lee_Bee]

Thank you, I will do that. The reading of the TVS diode I meant in comparison to the 100 ohms.