What is this resistor?

[Nozzleman]

I am trying to identify and source this resistor. I talked to Mouser tech and when the part number did not cross they were done. As I was sitting there, another customer took pity on me and came over and said it was a snubber resistor for an actuator circuit.

The capacitors were smoked (not uncommon) and this resistor. Before I drop ~$250 for a reman ECM, I thought I would attempt a repair.

It is marked
476M
+10K ]

In this picture it is the gold blob to the left of the blue capacitor.
https://www.supermotors.net/registry/media/861031

I have successfully swapped the capacitors and ended up with working ECM's for less than a dollar.

Thanks in advance.

 

[jpanhalt]

It is probably a 47 uF tantalum capacitor, not a resistor..

John

 

[Nozzleman]

There are others on the board marked:
105K
+25K]

I see no ohm symbols.

 

[jpanhalt]

This might help you: https://www.wikihow.com/Read-Capacitor

John

 

[Nozzleman]

Thank you for your help.

 

[debe]

Heres a pic of one on a Ford Falcon ECU. Its a 47uf Tant cap.

 

[fezder]

my vote goes too to tantalum they are pretty reliable, i mean they don't fail often, right? at least compared to electrolytics

 

[jpanhalt]

Modern tantalums are quite reliable (Source: https://www.cde.com/catalogs/AEappGUIDE.pdf ):

But you must pay attention to the sometimes low ripple current rating of tantalums: **broken link removed**
When they fail, particularly with reversed polarity, it can be spectacular.

John

 

[dr pepper]

105k 25k a 1uF 25v tanatlum

As mentioned unlikely to be the fault, tants are very reliable, and often when they go they go bang.

Also 'snubber' isnt something I'd call it allthough maybe not altogether wrong, its more likely to be a bypass capacitor for filtering the supply to one or more of the ic's.

Be very carefull soldering t

 

[Nigel Goodwin]

my vote goes too to tantalum they are pretty reliable, i mean they don't fail often, right? at least compared to electrolytics

People keep claiming this, but in the years when they were used in TV's they were spectacularly unreliable - with people here claiming that was because they 'only' used 25V rated ones on a 12V regulated rail.

They have certainly been rare in domestic gear ever since - which made fault finding more difficult, as you could just look for any tants in a set

Buy on a plus point, they don't dry out or go high ESR, they just go S/C or explode.

 

[fezder]

ah, thanks nigel, didn't know about that.

 

[KeepItSimpleStupid]

FWIW:

Some of the early Tantalum capacitors had problems. This info basically comes from the TekScopes yahoo groups. I think we are looking at the 80's time frame.

 

[tvtech]

This is funny for me since ETO changed to the xenForo Format...

Anyways, Tantalum Caps were mostly designed for timing applications...hopeless for any smoothing stuff or handling any kind of ripple.

I built a Linear PSU once and relied on a little bit of help from them....they were continiously cross and angry with me and at the output of my PSU. Fair enough it was a 10A Linear supply that had 20000MF of smoothing.....all the Tants had to do was stop any crap at the Output of the PSU....

They always caught alight.....That was is the early Eighties. I have learn't a bit more since then....

I hope you enjoyed this guys

My fulckups can maybe....just may maybe help others learn.

All the best,
tvtech

 

[debe]

If they are so unreliable, how come a large company like Bosch use them in engine management computers?

 

[jpanhalt]

The key word is "used to be." That is why in my post (#5), I qualified my comment by referring to modern tantalums. You still need to watch for the ripple current. And reversed polarity is a bang.

John

 

[dr pepper]

In the early 90's they dried up and were difficult to get, I wonder of that was the time when they were unreliable in telly's.

 

[Brevor]

The key word is "used to be." That is why in my post (#5), I qualified my comment by referring to modern tantalums. You still need to watch for the ripple current. And reversed polarity is a bang.

I agree with John, working with this stuff for over 35 years I find modern tantalum caps to be very reliable.

 

[tvtech]

Tants excel in some applications.

In others, they fail with spectacular results...

I agree with John, working with this stuff for over 35 years I find modern tantalum caps to be very reliable.

I know already this post is screwed up

What I am(was) trying to say is Tants are good for certain applications.
Don't stress them with any kind of ripple though or put any kind of pressure on them. They don't like that. Way too small to do any serious work other than minor applications that require lots of Microfarad's in a very small package.

They are great at helping to provide stable Voltage rails close to IC's. Because they are small and have a large capacity and thus can be placed close to the IC/rail they are serving.

The real hard work is done "upstream" from them. Be the design SMPS or Analogue, the old and trustworthy bulky Electrolytic is the workhorse that handles all the bulk smoothing.

I feel better now

Regards,
tvtech

 

[Brevor]

Tvtech, as usual you are correct. I should have said "modern tantalum caps are very reliable when used properly.
Thanks.
brevor

 

[tvtech]

Hi Brevor

I never mean to be clever or full of intelligence.....my posts here are all the stuff I have been through. First hand.
You will never find tvtech talking about stuff he knows nothing about. Or guessing.

Put in a nutshell, I hope I encompass what ETO stands for....

Truth
Honesty
Facts

Three little words that will ensure this sites survival. Times are hard Worldwide now.
Lot's of older sites are taking strain. Absolutely accurate info draws people.

Not guessing games like many sites out there....Try this or just do this and see if this helps...nah. ETO is a proud community of good people that give their very best. I know I do as cranky as I am

Thanks Brevor for your post above. Much appreciated but not really necessary.

Just tvtech telling things the way they are

All the best
tvtech

 

[fezder]

tech, wise words, think about it ''try it, you might lose expensive components or not, you might even lose your life or not, but i warned.'' Here people say right away if i'm not enought qualified, and that is nothing to do with personal opinions, just because no-one wants other get hurt...this is the way i see it. Like microwave ovens, no way i try to repair those beasts, even thought they are ''simple'' in ways of component quantity.

cranky or not, knowledge presses far more. of course, if person is complete POS, no-one listens him/her because of attitude. But, feedback is between listeners ear. I even don't remember when i would have gotten angry from other persons opinions.

feedback welcome ;D

ps, tech, what is your avatar? looks interesting

 

[tvtech]

Hi Fez

Avatar is the final X2 design. Have more testing to do even though my heart says its bulletproof.

Around three of these being used for all kinds of stuff. Watching daily how well they stand up to use/abuse. Circuitry is 100%...label can be better though.

Release will be early January 2014. Wish me luck Buddy.

Regards,
tvtech

 

[fezder]

sadly x2 doesn't ring bell...

still, thumbs up for ya!