I need to identify this chip in order to replace on an expensive camera lens. The code TF1 and TF2 are printed on the board to signify the issue is with the focus motor control. The core is 1mm thick by 3.5mm length.

photo of component (Image source)

photo of PCB (Image source)

photo of PCB (Image source)

Thanks in advance.

  • \$\begingroup\$ That is an inductor/transformer, not an integrated circuit (hence the TF designation). \$\endgroup\$ – isdi Nov 13 '18 at 14:53
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    \$\begingroup\$ That is a transformer, hence the identifier TF1. Unfortunately, being from a mass produced lens, it is likely to be custom made. However, with a bit of luck we can find out if there is a replacement for it, if you give us some more details of what other parts are around it, for example what chip drives it. If we can find which chip drives this transformer, and we find its datasheet (a very big if), there we might find some hints to what it is. Alternatively, have you searched for a schematic for your lens online? \$\endgroup\$ – Elmesito Nov 13 '18 at 15:00
  • \$\begingroup\$ I have tried finding the data sheet with no avail. The board is from a Sigma EX APO DG 70-200mm 1:2.8 II Macro HSM drive.google.com/open?id=1CAo2hxbUneItw4ao-T-yz4GZ7sgiZLTt drive.google.com/open?id=19SC0EAcDManYIGTpLNsQaSksOqryN5gb i believe the connection comes from the 8202 820 \$\endgroup\$ – Factulas Nov 13 '18 at 15:37
  • \$\begingroup\$ Some size measurements would help in narrowing it down, but as user156047 says, it could well be a custom wind, even if it is on a standard core. \$\endgroup\$ – Phil G Nov 13 '18 at 16:29
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    \$\begingroup\$ What makes you think that those parts are faulty? \$\endgroup\$ – duskwuff Nov 13 '18 at 18:36

Those are transformers and it is very likely the these were custom-made for this circuit (even if the core is standard, the coil windings are unlikely to be). So I doubt you would find a replacement unless you go through an authorized manufacturer/repair channel.

However, being transformers it is very unlikely that these parts are damaged. You have to either burn the coils or crack the insulation to make that happen, both of which are somewhat unlikely in low-power circuitry. Furthermore, the ferrite body does not seem to have undergone any overheating.

If you are so compelled, you can test the continuity of the parts and their impedance with an LCR meter. You should be able to determine if there is an obvious issue (e.g., shorted or open windings). But I would look at other surrounding parts first.


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