DNT M40FM squelch stuck open
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DNT M40FM squelch stuck open
A while ago i bought a joblot of radios that wasn't working and DNT M40FM was one of them. The fault on it is the squelch stays open even when turned all the way up. I can't find a clear diagram on this radio does anyone have any idea ?
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Re: DNT M40FM squelch stuck open
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Re: DNT M40FM squelch stuck open
Thanks alot. r47 was missing so i replaced that but still not working.I'll have another look when i get the time.
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Re: DNT M40FM squelch stuck open
Notorious for dry joints especially on the through hole pcb links. It will more than likely be the MC3357 if chip at fault.
My lovely boss back in the day bought a thousand of them all returns that i had to look at when no other repairs came in the door
My lovely boss back in the day bought a thousand of them all returns that i had to look at when no other repairs came in the door
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Re: DNT M40FM squelch stuck open
This one has missing parts and wires cut. Any change you have a photo of one open the top side ?
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Re: DNT M40FM squelch stuck open
Hello
Photos
@+
Claude
Photos
@+
Claude
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Photo Collector CB RADIO
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Re: DNT M40FM squelch stuck open
Hello
Only this one
@+
Claude
Only this one
@+
Claude
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Re: DNT M40FM squelch stuck open
Thanks for that it looks like i'm missing a few parts.
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Re: DNT M40FM squelch stuck open
All the arrows are the part i'm missing along with a few missing wires. Do you know the value of these parts ?
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Re: DNT M40FM squelch stuck open
Anyone ?
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Re: DNT M40FM squelch stuck open
Not all of the M40's have this modification, I have seen ones with no components on the solder side, a couple of parts and the full modification as per what Claude has posted. There are also component changes on the other side too. Just in case you have one with a different modification.
The values on a M40 I have here (which is identical to Claude's) are:
Hope this helps.
The values on a M40 I have here (which is identical to Claude's) are:
Hope this helps.
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Re: DNT M40FM squelch stuck open
Thanks mate i'll put them parts in and see if there is any difference.bitbang wrote: ↑18 Aug 2023, 11:54 Not all of the M40's have this modification, I have seen ones with no components on the solder side, a couple of parts and the full modification as per what Claude has posted. There are also component changes on the other side too. Just in case you have one with a different modification.
The values on a M40 I have here (which is identical to Claude's) are:
M40_an.jpg
Hope this helps.