Trying to fix remote for Sony TV

[Nigel Goodwin]

I only have avaliable 1/4 watt.

I doubt they would fit - you might have to buy tiny ones - you'd have to buy SM ones anyway, so makes no difference buying tiny wire ended ones.

Space isn't an issue - you don't have to fit the resistor on the same footprint - available height between PCB and keypad is likely to be the issue, hence my suggestion of tiny wire ended resistors.

 

[starLED]

I doubt they would fit - you might have to buy tiny ones - you'd have to buy SM ones anyway, so makes no difference buying tiny wire ended ones.

Space isn't an issue - you don't have to fit the resistor on the same footprint - available height between PCB and keypad is likely to be the issue, hence my suggestion of tiny wire ended resistors.

I saw an interesting product, adhesive conductive silver paste, to be used for repairing PCB traces.
Can I use this to repair pads for resistors?

 

[starLED]

Maybe the best would be to buy some conductive glue and glue all resistors and traces , without soldering, because the area is too small, I doubt that I can solder eveything without melting again.

 

[Nigel Goodwin]

Maybe the best would be to buy some conductive glue and glue all resistors and traces , without soldering, because the area is too small, I doubt that I can solder eveything without melting again.

Soldering is easy, and accurate - gluing (if it would even work) is going to be a LOT more difficult.

 

[starLED]

Soldering is easy, and accurate - gluing (if it would even work) is going to be a LOT more difficult.

Look at the picture how close are R2 i R1, how to solder either one without melting the other one?
That's happened to me.
I still have to glue some traces and pads on spot in order to put SMD resistors.
I saw this silver conductive pen, is it possible to repair with this?

 

[starLED]

I have laid out my repair setup.
I have put copper adhesive tape on traces so that I can solder traces and tape and then SMD resistors.
I will put R0806 R1 resistor 2R70 instead of R1206, hope that's ok.
Any advice would be appreciated.
Here is the setup:

 

[M.Joshi]

That's not a bad job. You may find it harder to solder smaller components. There still appears to be some sticky residue next to R2.

How secure is the tape? You may want to add a drop of superglue at points where you won't be soldering.

If the top of R2 goes to the bottom-right leg of Q1, you might be able to solder the resistor between that leg and the adjacent track. Just check that it won't clash with the button membrane once it's in place.

 

[JimB]

I am impressed, looks good for a first attempt.

I will put R0806 R1 resistor 2R70 instead of R1206, hope that's ok.

Yes that should be OK, as long as there is not a big current flowing in the resistor when the control is operated.

One thing that I do notice, originally the small resistor was marked 101, this would suggest that the value of that resistor was 100 Ohm.
Your new resistor is marked 1000, this may be OK ie 100 and no zeroes, rather than 1000 Ohm.
Maybe worth checking with your multimeter.

JimB

 

[starLED]

Tape is very sticky, it is secured.

 

[starLED]

I am impressed, looks good for a first attempt.


Yes that should be OK, as long as there is not a big current flowing in the resistor when the control is operated.

One thing that I do notice, originally the small resistor was marked 101, this would suggest that the value of that resistor was 100 Ohm.
Your new resistor is marked 1000, this may be OK ie 100 and no zeroes, rather than 1000 Ohm.
Maybe worth checking with your multimeter.

JimB

I checked with multimeter, it is 100 Ohms, it's just a different marking.
Previous R1 resistor was marked 2R7, and this one is 2R70.

 

[JimB]

I checked with multimeter, it is 100 Ohms, it's just a different marking.

OK sounds good.

Previous R2 resistor was marked 2R7, and this one is 2R70.

Yes, I had already sussed that one, no problem.

JimB

 

[starLED]

If the top of R2 goes to the bottom-right leg of Q1, you might be able to solder the resistor between that leg and the adjacent track.

I am not sure that is supposed to go to right leg.

 

[starLED]

There still appears to be some sticky residue next to R2.

That's not residue, it's R letter scraped off accidentaly.

 

[Nigel Goodwin]

I am not sure that is supposed to go directly to leg.

I would suggest it goes to the bottom left leg of the transistor, which should be the base - the bottom right leg is the emitter, and goes down the board somewhere. The 2.7 ohm goes to the top connection (collector) and is the current limiter for the IR LED.

 

[M.Joshi]

That's not residue, it's R letter scraped off accidentaly.

This:

 

[starLED]

This:

View attachment 128528

There isn't residue there.

 

[M.Joshi]

There isn't residue there.

It looks like some sort or adhesive possibly from the foil tape backing?

 

[starLED]

It looks like some sort or adhesive possibly from the foil tape backing?

No, there's nothing there, I am not sure what you see, but I cleaned it with acetone.

 

[starLED]

Here is the end of remote saga.
I have tried to solder copper tape to trace, but with no success. Tape came off beacuse of iron heat, and I couldn't hold it in place, it was just too small. Perhaps I should've used super glue.
I decided to use 1/4 watt resistor of 100 Ohms and I joined it from lower trace to left leg of transistor. Because of that I couldn't use mute button because resistor is over the button switch.
Then I soldered SMD 2R70 resistor from pad to trace, but for some reason it didn't conduct, so I soldered directly upper leg of transistor to trace using resistor as bridge, considering resistor was just 2,7 Ohms, so probably wouldn't be problem.
And it worked, remote works now, so I am happy.
Here are pictures, it looks ugly, but I cleaned residue afterwards.

 

[KeepItSimpleStupid]

Perhaps I should've used super glue.

I think I mentioned it somewhere that it isn't a good choice because of temperature. it can be used to temporarily secure a component though.