Hello, I have a 4200 and have falling out channels... after cleaning the relais contacts it works for maybe 1 or 2 days... then the same...
I have already looked for one but cant find a substitute... its 24V...
Somebody firm in this matter?
Christoph
I have already looked for one but cant find a substitute... its 24V...
Somebody firm in this matter?
Christoph
I would say make absolutely sure the relay is at fault first... yes they are common issues but they usually respond to cleaning. Make sure you clean the contacts correctly and effectively. If it seems OK for a while and then goes faulty again then don't discount the possibility the fault is elsewhere and it is just the action of disturbing things that temporarily 'fixes' it. Look for dries and that kind of thing.
Yes, bad or cold joints. They often look like this:
Clean the relay contacts by pulling paper or card soaked in alcohol through the contacts. Make sure you clean the correct contacts which will be the normally open ones.
Clean the relay contacts by pulling paper or card soaked in alcohol through the contacts. Make sure you clean the correct contacts which will be the normally open ones.
The first relay looks more substantial, the second seems more like a small signal type. If yours is like the first then I would be surprised if the contacts would not clean.
Bridging the contacts is 100% definitive test but remember you may get unwanted thumps and noise from the speakers at power on and off. If you leave the top off the relay you can just gentle touch the contacts when the fault occurs and see if the contacts seem intermittent.
The coil resistance should be similar to the original, a little lower is normally OK, so 900 ohms, 700 ohms, all OK but not something like 300 ohm unless you clould be sure the relay driver stage is OK with that.
Bridging the contacts is 100% definitive test but remember you may get unwanted thumps and noise from the speakers at power on and off. If you leave the top off the relay you can just gentle touch the contacts when the fault occurs and see if the contacts seem intermittent.
The coil resistance should be similar to the original, a little lower is normally OK, so 900 ohms, 700 ohms, all OK but not something like 300 ohm unless you clould be sure the relay driver stage is OK with that.
Careful alignment of the contacts is mandatory.
During cleaning, if the contacts are bent from original shape, they won't close tightly.
Also, the wires to the moving contacts should allow free movement.
It's a delicate process, something that non-techs don't understand.
During cleaning, if the contacts are bent from original shape, they won't close tightly.
Also, the wires to the moving contacts should allow free movement.
It's a delicate process, something that non-techs don't understand.
Well, the evidence is pointing towards the relay. The one you link to looks OK, they are fairly generic as long as you get one of the correct pin outline.
Yeah... thanks! I will try a new one... But how will I know if the pinout is identical?
The coil is obvious... measuring 1,2KOhms...
They often 'just are' as they are pretty generic. Look at your amp and check though. It should be easy to see which pin is which.
Using a magnifying glass or goggles and a good ruler with MM and measure the pins underside view.
Reputable things like relays usually have a detailed PDF diagram with actual measurements for comparison.
Reputable things like relays usually have a detailed PDF diagram with actual measurements for comparison.
Whats the diode in the plan for? Should I put it on the new one? Or a new one? IN4007 or something?
All the best!
All the best!
So, A1 and A2 is the coil... 14, 24 and 11, 21 are connected... 12 and 22 or not connected... I know on the foto they are together with 11 and 21...
That should be it... I ordered today... will give feedback soon!
Thankyou very much for all the help! Great forum! Thanks!
That should be it... I ordered today... will give feedback soon!
Thankyou very much for all the help! Great forum! Thanks!
The diode is to absorb back emf generated by the abrupt switch off of current in the relay coil. As the magnetic field collapses it will induce a (possibly) high reverse voltage cross the coil. The reverse biased diode absorbs it.
A 1N4002/3/4/7 is fine but watch the polarity.
A 1N4002/3/4/7 is fine but watch the polarity.