LM317M

[Skeleton Man]

Hi all,

I have a dead Yamaha soundcard with an LM317M chip, and the chip has the middle
leg missing.. just wondering is this a normal thing (ie. delibaretly removed) or
would this be the reason the card is dead ? if so is it easy to get a
replacement ?

Regards,
Chris

 

[John Popelish]

Skeleton Man wrote:

Hi all,

I have a dead Yamaha soundcard with an LM317M chip, and the chip has the middle
leg missing.. just wondering is this a normal thing (ie. delibaretly removed) or
would this be the reason the card is dead ? if so is it easy to get a
replacement ?

Regards,
Chris

No, it is not normal, since the middle pin (on the TO-220 package) is
the output.
See:
http://www.national.com/ds/LM/LM117.pdf page 2.

But the tab is also the output, so if there is a connection to the
tab, then it is possible for it to be used without the middle pin. Is
the pin cut off, or blown (melted) off?

These are quite common and not very expensive.
--
John Popelish

 

[Skeleton Man]

No, it is not normal, since the middle pin (on the TO-220 package) is
the output.
See:
http://www.national.com/ds/LM/LM117.pdf page 2.

But the tab is also the output, so if there is a connection to the
tab, then it is possible for it to be used without the middle pin. Is
the pin cut off, or blown (melted) off?

Looks like it's normal... mine matches the D-Pak package which doesn't use the
middle pin.. and the tab is connected too.. I mistook it for being broken.. tho
why they leave like 1mm of pin still there I'd like to know ?

Thanks for the help... looks like whatver the problem is, isn't visible.. (I do
realise the card is worth all of 10 bux, but next time it might be a $100 card
that goes and you wouldn't just toss that..)

Regards,
Chris

 

[Dominic-Luc Webb]

On Mon, 17 Jan 2005, Skeleton Man wrote:

Hi all,

I have a dead Yamaha soundcard with an LM317M chip, and the chip has the middle
leg missing.. just wondering is this a normal thing (ie. delibaretly removed) or
would this be the reason the card is dead ? if so is it easy to get a
replacement ?

Regards,
Chris

I suspect this is not the famous LM317 voltage regulator, but some
proprietary component.

Dominic