TN-D710E capacitor replacement


Julian
 

Hi, I have manage to successfully change the ceramic filters on my TM-D710E, but I knocked off C509 in the process. It's way too tiny for my soldering skills and tools so, I was wondering if anyone can help (info wise) with a larger replacement. I am not sure what type of capacitor it is, ceramic or RF. Probably ceramic. Service Manual pg 17, part no CC73HCH1H560J (chip C   56pF   J).
Regards, Julian, MØIPU


Leo Bodnar
 

Julian,
Have you fixed it yet?
It's a cap that passes IF 455/450kHz to the detector so not really "RF" or a critical value.
Leo


Julian
 

Hi Leo. Tnx for info. I have managed to decode what type of cap is, ceramic multilayer, ±5%, SMD 0402. 56pF, 50V. I have done few trials on a test board and successfully soldered few caps of this size under the microscope using hot air. It's crazy. They are under 1mm I believe. If you see them on the wking table you'd think they are specs of dust... I haven't soldered the TM-D710 one as I have run out of free time and also haven't felt that well recently. Maybe next week. 
Unfortunately Kenwood/JVC doesn't make.it easy to decode their part nrs. I would assume, for a trained eye, it's not a problem. With Panasonic for ex, on the other hand, if you ever type one of their part nr in Google you will find a lot of info, specs etc. 
73 regards de J, MØIPU YOЗFCA


Jim Shorney
 

An ordinary soldering iron is just fine for SMD parts and you don't risk blowing the part into your carpet. :)

73

-Jim
NU0C


On Sat, 13 Mar 2021 06:53:43 -0800
"Julian" <iulianp@msn.com> wrote:

I have done few trials on a test board and successfully soldered few caps of this size under the microscope using hot air.


Julian
 

That's true. You mean my lab floor... He he he. I did try the iron, but it's bk to sq 1. Either way, you have got to hold down the SMD. With the iron the SMD gets sucked onto its surface. It's also a nightmare. I waggled the iron and the cap ended - I wish I could tell you, I couldn't find it anymore. It joined the other specks of dust in the room. He he.

73, regards de J, MØIPU YOЗFCA


Leo Bodnar
 

If you are struggling, send the PCB over and I will put in for you. I am in Silverstone.  I have 0402 caps.
The smallest caps I have manually worked with are 0201 - they love falling down PCB vias, heh.

By the way I have replaced a filter on my TM-D710E and found that it had bypass caps already designed in - which I have not expected.
Leo


Julian
 

0201. Don't even go there!
Thanks Leo. Let me see how I will be getting on with this one. For me it is also a bit of a challenge/hobby. I like to do this sort of things myself (within limits...). I have also ordered abt 70 electrolytics for my IC820H. Fingers crossed with that free time.
I'll return with some feedback.

73, regards de J, MØIPU YOЗFCA


Julian
 

Hi agn. Found a bit of a free time tdy and managed to complete the cap job (I still need to put together the TM-D710). Here are some pics. Hot air didn't work in the end, I believe I covered too much area around the cap with Kapton tape (out of fear!). It would not reflow at 350°C (660°F) no matter what. The size of pads are also extremely tiny compared to ones on my test boards (would not heat up, probably). So, I cleaned up with isop, steadied my hand and held the cap on the board (by far the most diff part of the job probably), used a bit of flux, the iron and voila - see pics. Tnx all. I'll probably come back once I'll put together the TM-D710 with some feedback.


Overall pic





Joint view




Matchstick head next to the cap






73, regards de J, MØIPU YOЗFCA






Julian
 

Here is some final feedback. Applied this mod ( link ). All is fine now. Strong audio on all VFO-s all modes (FM, NFM). I haven't got the eqp to actually measure anything (uV, dBm etc) , only by smell ( no magic smoke ), visual ( no flames ), touch ( no intense heat ). I have still got Kapton tape attached to my slippers soles. All good.

Tnx and 73, regards de J, MØIPU YOЗFCA


Leo Bodnar
 

Well done, Julian!
I have replaced 455kHz NFM filter with a sharper slopes one, haven't done much testing either.
Leo


Julian
 

Brilliant, Leo. Glad to hear another happy ending story. For me it was a bit more difficult as it was my first adventure into the SMD world.
Mni tks. 73 de J, MØIPU YOЗFCA