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-   -   Dead Naim remote (https://www.vintage-radio.net/forum/showthread.php?t=167106)

Edwar65 23rd May 2020 8:10 pm

Dead Naim remote
 
3 Attachment(s)
Has anyone had any success in repairing remote handsets for A CD player. Mine has decided to stop working,checked obvious things like batteries and connections etc.
It was working,but dropped it onto hardwood floor and that was it!!!
Looking inside it's just a simple PCB with a few caps,chipset and diode at end,can't think how a drop could damage it.
I wonder if replacing the caps could bring it back to life?? It works on the rc5 protocol and I understand other remotes will do the job,but may not give me the functions of original item.

TonyDuell 23rd May 2020 8:12 pm

Re: dead naim remote
 
Does the chip/chips have a recognisable number?

There is likely to be some kind of clock crystal or ceramic resonator in there (it may look a bit like a capacitor). Those can break if the remote is dropped.

toshiba tony 23rd May 2020 8:41 pm

Re: dead naim remote
 
Should be relatively easy to sort, if it's been dropped that should narrow it down. Often, without impact damage the IR transmitter can go dry. Dab some solder on it, you may be lucky.

Sideband 23rd May 2020 8:47 pm

Re: dead naim remote
 
Quote:

Originally Posted by TonyDuell (Post 1251199)
Does the chip/chips have a recognisable number?

There is likely to be some kind of clock crystal or ceramic resonator in there (it may look a bit like a capacitor). Those can break if the remote is dropped.

Yes and its visible in the photo....looks like a large ceramic cap. If you can, scope it to see if it's oscillating. It should have a frequency printed on the side (for example 10.0 or 106 for 10 Mhz). If its faulty, it should be possible to find a suitable replacement.

Edwar65 23rd May 2020 9:22 pm

Re: Dead Naim remote
 
Can only see what's in pics 4 caps at base a diode and resistor and chip in middle resistor at top next to ir transmitter. Has had issues with it in past,but not completely malfunctioning as now??
No access to scope,I'm afraid. Larger looking ceramic cap marked up 3.64M??

Edwar65 23rd May 2020 9:53 pm

Re: Dead Naim remote
 
Resoldered all joints still no joy I'm afraid??

buggies 23rd May 2020 10:20 pm

Re: Dead Naim remote
 
Quote:

Originally Posted by Edwar65 (Post 1251252)
Can only see what's in pics 4 caps at base a diode and resistor and chip in middle resistor at top next to ir transmitter. Has had issues with it in past,but not completely malfunctioning as now??
No access to scope,I'm afraid. Larger looking ceramic cap marked up 3.64M??

It is a ceramic resonator 3.64MHz.
Quote from a web site:-
"Remote Control IC
Remote controls have increasingly become a common feature for TV’s stereos, VCR’s, and air conditioners.
Oscillation frequency is normally 3.2-4.0MHz, with 3.64MHz being the most popular.
This 3.64MHz is divided by a carrier signal generator so that approximately 38kHz of carrier is generated."

Edwar65 23rd May 2020 10:41 pm

Re: Dead Naim remote
 
Any thoughts on a replacement and where I can get one the other ceramic cas are marked 20 would that be 20uf?? Or would anyone have a second hand marantz or similar remote I can buy,I know the old marantz cd player remotes will do the job??
Ta

Radio Wrangler 23rd May 2020 10:57 pm

Re: Dead Naim remote
 
There are two small cermic capacitors, normal disc shaped ones. They will be small in value, a few tens of pF is normal. They are used to create phase shift and loading for the ceramic resonator.

The ceramic resonator is a piezo-electric mechanical resonator made out of similar stuff to ceramic capacitors and it needs only two legs (some have three). Therefore it looks a lot like a ceramic capacitor. It will be connected across two pins of the IC and one of the two small ceramic capacitors will go to ground/common from each end.

Ceramic resonators (and quartz crystals) can be damaged by shock.

Other possible faults are cracked tracks on the board, bad solder on the battery spring to board joints and the IR LED.

You don't need to start sourcing another remote just yet.

Examine the board in minute detail. You may be lucky.

Try a scope on each end in turn of the ceramic resonator while pressing buttons. You should see it burst into life. It would eat batteries if kept running all the time, so it runs only in a burst when a button is pressed.

If no joy, look on the resonator for markings, they usually have the frequency marked on them.

David

Edwar65 23rd May 2020 11:08 pm

Re: Dead Naim remote
 
Hi radio wrangler. I only have. Scope so unable.to investigate that. The resonator is marked up 3.64M.
I've resoldered the battery and ir legs but still nowt. I'm also unable to locate a resonator of that size on the web???

Radio Wrangler 24th May 2020 5:22 am

Re: Dead Naim remote
 
Does it have three legs?

https://uk.rs-online.com/web/p/ceram...ators/1048550/

But it's no longer stocked.
Farnell have a surface mount one at 3.68MHz which might be within the receiver's tolerance. You can also try Mouser and Digikey.

David

barretter 24th May 2020 12:12 pm

Re: Dead Naim remote
 
You say you've checked all the obvious things but you don't say that you've checked if the IR LED is working. The only time I've had a remote stop working it turned out to be a dead LED. I apologize if you've already done that.

Edwar65 24th May 2020 4:44 pm

Re: Dead Naim remote
 
Resonator has 2 legs. Any ideas as to how to check if it is dead and where to find a suitable replacement,are they all the same

Ambientnoise 24th May 2020 4:53 pm

Re: Dead Naim remote
 
Wouldn’t an old remote control of almost any variety be a likely source of a resonator ?

Edwar65 24th May 2020 5:26 pm

Re: Dead Naim remote
 
Possibly,I have an old dvd remote. Would the resonator have to be same spec and would the it from that be compatible????

Ambientnoise 24th May 2020 5:39 pm

Re: Dead Naim remote
 
Don’t know, best to check for any markings and if it looks physically similar. Nothing to lose if all else fails. I must admit that I think a cracked track (have you looked at the legs on the chip under a magnifier) or the IR diode are more likely culprits. Can you check if it is drawing power ? Some remotes have several modes, could this be in an unwanted mode ? Can you see the diode flash via a phone/digital camera (or hear some hash on a close by AM radio) when you press a button ?

Leon Crampin 24th May 2020 5:41 pm

Re: Dead Naim remote
 
Your controller looks very like a Philips one which I had for a CD player. If you suspect the resonator (a good bet, as they're easily damaged by shock), you could seek out some old Philips controllers of similar vintage. They did at one time have a standard protocol for nearly all their products RC-5? so you could be lucky.

Another favourite site for a broken joint is where the battery contact springs are soldered to the board. If you haven't already been there with a soldering iron, it might be worth a good look.

Leon.

Edwar65 24th May 2020 6:17 pm

Re: Dead Naim remote
 
Yes it's based around rc5 protocol. As you say,I will check what other unused remotes I have for parts and try checking joints and tracks again with a magnifier

Sideband 24th May 2020 6:34 pm

Re: Dead Naim remote
 
I used to find the IR transmit diode used to go dry jointed. No idea why. Good idea to seek out other RC5 remotes. Probably use a similar/same ceramic resonator.

Edwar65 24th May 2020 10:29 pm

Re: Dead Naim remote
 
Hi all.
I found a disused Toshiba dvd remote ,took out the ir transmitter and put it into the naim unit and it worked,bingo!!!
Many thanks for the guidance,always an experienced tech on here that can help out,very greatful for the help.


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