please help id this part and help fix

[ronnelldotson]

hello i have a small practice amp that i have had for a while. today i went to plug it in and i heard a slight pop and it stoped working and smelled funny. i opened it up and did not see anything at first. then i noticed that this little thing was damaged. the amps power light still comes on but does not put out any sound. so i figure this has to be the issue ....... i found a lm18752 5 pin out put module. i was wondering if they all hook up the same or is their any diff. mine has a red wire on one side and white wire on the other side of a lil electric board the module is linked to .... can you please help id and find the part i need ..... i sent a pic as well so you can see what it lookes like ... i can not see numbers on it cause it is melted

https://i1235.photobucket.com/albums/ff424/godsbassplayer/th_IMG_20110720_133611.jpg

 

[KJ6EAD]

It's an audio amplifier chip of course, but which one. A well-lit picture of just the dead part taken with a camera with a few megapixels would help. Do you know the brand and model of the amplifier? Do you know what the DC supply voltage is? Why did you mention the LM18752?

 

[ronnelldotson]

it is a ibanez model sw15 and i mention the lm18--- cause i was messing around on the net and saw a part that looked like the part thats in my amp thats busted ... as u can tell i dont have a clue as to what this stuff really is ... i can understand well and if i had the right part sure i could fix it ...
i have a photobucket link above with a pic of the dead part.... and im unsure what the dc supply is i still have all of my paper work for it would it be in the user manual or on the amp

 

[KJ6EAD]

It's a TDA2040 by ST Microelectronics.
http://www.st.com/stonline/products/literature/ds/1460.pdf

If you have a local electronics supplier, they may stock this or:

$1.72 at http://www.newark.com/stmicroelectronics/tda2040v/ic-audio-pwr-amp-ab-22w-pentawattv/dp/89K1046

$2.25 at http://www.jameco.com/webapp/wcs/st...amecoall&ddkey=http:StoreCatalogDrillDownView

$3.70 at http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=497-3027-5-ND

$3.70 at http://www.mouser.com/ProductDetail/STMicroelectronics/TDA2040V/?qs=sGAEpiMZZMtxdzBvM0rKcY7UJTcHiRVJU%252bJjCFkyL8E%3d

It will probably come down to a comparison of shipping costs for you.

 

[ronnelldotson]

is it any diff between the TDA2040 and TDA2040v

 

[KJ6EAD]

is it any diff between the TDA2040 and TDA2040v

Yes, but it is of little relevance for your application since yours is chassis mounted. The vertical (V) and horizontal (H) designations only differ in the way their leads are bent for mounting on a PCB.

https://www.electro-tech-online.com/custompdfs/2011/07/CD00004635.pdf
https://www.electro-tech-online.com/custompdfs/2011/07/CD00004758.pdf

Be sure to follow the mounting guidelines and use heat sink compound.

https://www.electro-tech-online.com/custompdfs/2011/07/CD00003783.pdf

 

[ronnelldotson]

ok thanks

 

[Ziddik]

hello i have a small practice amp that i have had for a

https://i1235.photobucket.com/albums/ff424/godsbassplayer/th_IMG_20110720_133611.jpg

looks like its TDA2030A or Higher nor lower of TDA series.. Do u know the output voltage of its transformer? It must be tda2030 If the transformer is 12V but the tda2040 will also work on 12v supply..

 

[ronnelldotson]

ok so i looked at it .... i see a lil box deal that has a spool of wires inside its also on the same side as the power cable ... on it the sticker says
input 120vac 60hz
output 14x2 aco-4a

 

[ronnelldotson]

i work on cars as my hobby and this stuff you guys deal with is ruff.... i would take it to a shop but im in iraq and i cant practice with out it ...lol.... im really bored when im not being shot at so if i get lucky and fix it ..... ill be good if not ill just send it back home and dig fox holes till its time for me to come home ...lol

 

[Ziddik]

ok so i looked at it .... i see a lil box deal that has a spool of wires inside its also on the same side as the power cable ... on it the sticker says
input 120vac 60hz
output 14x2 aco-4a

if you are sure its a transformer then the output voltage will be 14x2=28V, can u post a picture of that thing?

 

[ronnelldotson]

im sure it is so does this mean that the part listed will work

 

[KJ6EAD]

I'd think some of your local techies could help or just have someone send you the TDA2040. There's no guarantee that replacing that part will solve the problem. It's a tough part with a built in thermal protection circuit so you should make sure the speaker isn't shorted before you replace the TDA2040.

 

[Ziddik]

..and u need to laminate the tda Ic between heatsink, dont touch the ic to heatsink directly

 

[ronnelldotson]

what do ineed to laminate it with

 

[KJ6EAD]

He's just talking about using heat sink compound to get a good thermal interface between the TDA2040 and the heat sink. I mentioned that in post #6. It's sometimes called heat sink grease, thermal compound or thermal grease.

 

[ronnelldotson]

ok yes i saw that ... i was thinking he was saying some thing else but ok got it ...

 

[Ziddik]

the ic will burn instantly if u did't laminate it and u might need to buy a new one!

 

[killivolt]

Wouldn't the laminate be between the old part and the sink he could just re-use it. Still you heat sink compound.

 

[KJ6EAD]

There are no mica or other thermal pads made for the pentawatt package, just use heat sink compound.