SVT 7 pro no speaker output

[lowell]

JPB,
Isn't it? Thanks for the link!! I'm gonna give this a shot I think. Once I get the main pcb board out I'll have better access to the IC. If ANYONE has any tips I'm all ears!

[MarkusBass]

IRS20955 is available from the first local shop I checked. But it would be too difficult to send it to the States.
If you are not feeling good about SMD parts soldering, I suggest finding a company in your neighbourhood that does it on a daily basis. If you search something like: "smt soldering services Chicago" in google, I'm sure you will find it. There must be thousands companies that do it and you don't have to reinvent the wheel.

Mark

[lowell]

Markus,
Do you do smd repairs? If so how do you go about it?

[MarkusBass]

Markus,
Do you do smd repairs? If so how do you go about it?

I do it if I have to. I just desolder parts, clean the board and solder new parts. As you already know, desoldering is the most difficult step. But you have all the information available on the internet (there are many videos on youtube). In general you need a hot air gun (or Chip quick), magnifiyng glass and skilled hands. Believe me that there are thousands companies that do it on a daily basis. For example: Rework/Repair Expert | Hand Soldering of PCBs | 847-797-9250 - is it in your neighbourhood? They also provide trainings: SMT Assembly Training Boot Camp Class | 847-797-9250

Mark

[Steve Conner]

I thought somebody mentioned earlier that the chip was obsolete and replaced by the IRS20957. This seems to be a drop-in replacement, and it's in stock at Digikey.

I would agree, if you have no experience in SMT work, get someone else to do it!

[MarkusBass]

I thought somebody mentioned earlier that the chip was obsolete and replaced by the IRS20957. This seems to be a drop-in replacement, and it's in stock at Digikey.

I mentioned this but the application note states that there are some differences in voltages required by each IC. Since this may require some modifications to the amp and modifying an amp before fixing it is a bad habit, I recommended to solder the original chip. Of course Lowell can read the application note and analyse how important are the differences between the old and the new chip. And it's up to him what to do with the amp.

Mark

[lowell]

At this stage I'm gonna fix it with the original chi to keep things simple. If the amp comes back or I get another in I will be more confident in SMD .... assuming I'm successful here. as long as I get my iron the rifht temp and use that quick chip it actually looks quite simple. I'm considering flowing QC over all pins for removal... then cleanup, flux paste, installation.

[lowell]

Got the IC out. Wasn't so bad! New IC should be here tomorrow.

[Jazz P Bass]

I take it you used the Chip Quick, huh?

[lowell]

Yep! Great stuff!

[MarkusBass]

Lowell,

Before soldering a new IC, you have to clean the pads. The surface for SMD components has to be flat. And it's not in your amp as least as far I can see on the photo.

Mark

[lowell]

I did, it just looks weird in the picture.

[lowell]

Thank you Chip Quik. I got the new 20955 in there and it's working and sounds great. Thanks Markus, Steve, JM and friends... thank you thank you! I now feel more confident in SMD repairs... even excited to perform them. Yay, electronics is fun!

[Jazz P Bass]

Glad to hear that you got it, Lowell.
I think we all learned a lot.
I can't wait for one of these to come in.

[lowell]

Sh*t I forgot to thank you too JPB. Right on.