Before I give up, I thought I'd just ask here in case anybody has a bright idea.
My 616 PBX has suddenly started cycling the green Day Mode light. It'll be on and stay that way for a long time, but then it'll give a hard click, the light'll go off, and Day Mode is off.
It still works, more or less, because when the Day Mode light is off I still get the dial tone for CO1.
However, the other CO lines are unavailable.
Any ideas for a simple fix?
I'm afraid I don't know much about these things. I just found one that seemed to work, plugged it in, attached some lines and have just been enjoying myself for a while. :-)
Extension 1 has too many phones on it, but that has never been a problem before.
Odd behaviour like that could indicate capacitors dying (depending on manufacture date, it could be 20-something years old), but I'd reduce the load on Ext.1 first, just incase it's that overloading the system's board... :)
The problem sounds familiar.
I think one of mine was doing this or something very similar when I first got it.
I believe the fault in my unit was a poorly operating relay. I seem to recall that it was a little bit depended on the position of the unit. I am not perfectly sure what actually removed the problem, but I applied to each relay inside a good mechanical jolt with a hard object.
Btw, all six CO lines should be accessible while the unit is off or in power-fail mode.
The C.O. lines each map to the first six station ports.
So, C.O. line 1 is available on port 1, C.O. line 2 on port 2 and so on.
The function of this is controlled by six power fail relays that are held when power is on; if it fails, they release and connect the station ports directly to the C.O. lines coming in.
Removed a bunch of phones from extension 1, put the fax machine on extension 2, and reset it...and now the Day Mode won't come on at all.
I believe it's probably done for, or beyond what I know to fix it.
Oh, well. It was cheap.
I believe it lasted almost 2 years, too.
Right now it's just converting pulse to tone and giving me CO1...so I'll probably disconnect it and do something else.
Thanks very much for trying to help.
I'd still say capacitors, not too hard to replace, just fiddly & time consuming, but worth it, I need to replace the capacitors in my two Amiga A600 computers (they're about the same age as my own 616) as they've belched out their electrolyte in a few places, and will be replaced with Tantalum equivalents, the only reason I noticed the caps were going bad was one of them was acting very oddly (not starting up, then randomly starting on it's own, and the FDD sending sounds through the audio output, etc.), so odd behaviour of electronics can often be those annoying little barrels of paper, metal and goop... :)
Quote from: unbeldi on November 26, 2014, 02:21:00 PM
Btw, all six CO lines should be accessible while the unit is off or in power-fail mode.
The C.O. lines each map to the first six station ports.
So, C.O. line 1 is available on port 1, C.O. line 2 on port 2 and so on.
This may vary by model; I think mine KX-TA616 has line 1 to port 1, line 4 to port 9.
Quote from: Owain on November 28, 2014, 03:19:38 PM
Quote from: unbeldi on November 26, 2014, 02:21:00 PM
Btw, all six CO lines should be accessible while the unit is off or in power-fail mode.
The C.O. lines each map to the first six station ports.
So, C.O. line 1 is available on port 1, C.O. line 2 on port 2 and so on.
This may vary by model; I think mine KX-TA616 has line 1 to port 1, line 4 to port 9.
Yes, it varies by EASAPHONE model line. The TA line is quite different from the T line.
The T line had discrete implementations of each CO and station port on the PCB, while the 'Hybrid' TA systems were modular in design and had plug-in cards for groups of station ports. Only the first port of each card mapped to a CO line, whence CO1-->1, CO4-->9
I think most collectors here are using the much cheaper and older models KX-T308(10) and KX-T616(10).
My 616 is having the same problem. After I switch it on it works for up to a few minutes, then the I/O IC switches it to power failure mode. I did some poking around and the only thing I could find, so far, is that the 1 farad capacitor isn't holding a charge. So, I'm going to try replacing that capacitor and see if that helps any.
Looks like we revived an old thread.
I thought my 616 died a few months ago, but it came back to life.
Issue was that we had a power failure. Once the power came back on, the 616 went nuts. Phones ringing in cadence as if there was an incoming call, and the relays inside the box were cycling through with a definite rhythm. I powered it off again and back on. Same thing. Powered it off for about a half hour and back on. Same thing. Brought it back up in programming mode. Same thing. Frustrated, I pronounced it dead and turned it off thinking that the power failure had also produced a surge. I have a power strip ahead of the 616, but who knows how good it might be as a surge protector. Maybe not at all.
So, after several months of it being turned off, I could not resist one more try. Viola! It worked and has continued to work now for a couple weeks. I have no clue as to what killed it in the first place, and I guess what ever it was had to fully discharge any memory in the chips that may have been kept alive by some capacitor buried deep within, but after sitting for so long un-plugged it came to life. Like Dr. Frankenstein: "It's Alive!!!"
If it has a battery, you could just pull that and reset it's memory, but if it has the supercap (a capacitor that holds a charge for quite a while) instead of a battery then that takes a bit more to discharge it, which is probably what yours did in either case (either dead battery or drained supercap)... :)
I never power mine down....it is always running...Doug
Quote from: twocvbloke on September 29, 2017, 07:14:26 PM
If it has a battery, you could just pull that and reset it's memory, but if it has the supercap (a capacitor that holds a charge for quite a while) instead of a battery then that takes a bit more to discharge it, which is probably what yours did in either case (either dead battery or drained supercap)... :)
I did pull the battery, and so, I suspect it was a cap. Like Doug, I never turn it off normally unless the power goes off, which is maybe an average of once or twice a year.
If you don't program your 616, there is no need for a battery, which is backup power to keep your programming while line power is out, and as such can just leave it out. Without a battery, it boots up to whatever the factory default settings were set to be.
If you have a battery, then you don't have that huge capacitor on the pc board playing battery until it is discharged.
I agree about not having a battery fitted. I have a couple of units that I use occasionally at shows. When I got them I hard reset them both to factory deffaults, which works ok for me. There is a place to fig a battery bu I never bothered and they work fine.
Remember caps don't always bulge on the top when they go bad. I've had some in LCD monitors that needed replacing but looked perfecly ok to the eye.
I find it odd that, according to the diagram in the service manual, there's another capacitor in parallel with the 1 farad capacitor but with the polarity the other way around. I've never seen anything like that before. I wonder if that might be an error in the service manual.
Quote from: James on October 01, 2017, 01:30:13 PM
. . . according to the diagram in the service manual, there's another capacitor in parallel with the 1 farad capacitor but with the polarity the other way around. I've never seen anything like that before. I wonder if that might be an error in the service manual.
Can you scan or clip that diagram and post it?
And, is that diagram for a 616 with a battery backup or the newer 616 with the battery replaced by a large capacitor?
The diagram is for the 616. It uses both a backup battery and the 1 farad capacitor. I had to make a copy by hand of the part of the circuit that I mentioned because the pdf file won't let me make a straight image copy.
I replaced the 1 farad capacitor and it seems to be running fine. It hasn't gone into power failure mode yet. I've only been running it for about half an hour though. I'll keep running it for a few more hours to see if there are any changes.
Unfortunately, it went into power failure mode after about an hour of being on. So, it looks like something else is causing the problem.
Could potentially be other capacitors in the system or power supply acting up, could be the "goo" they slopped about (assuming it's not been peeled off by now) that turns conductive as it ages causing the processor to go into power fail mode even if the power hasn't failed...
I didn't notice any goo on mine. It seems that the longer I leave it powered off, the longer it goes before tripping in to power failure mode.
In that case it sounds like another capacitor has copped it somewhere inside the system, only way to reliably test them is to remove them one by one and test them with an ESR meter as capacitors can look physically okay on the outside, but internally be completely stuffed, quite an involved task really... :-\
I wonder if it's worth it. I could end up paying more for capacitors than what I paid for the pbx.
I got a load of dead LCD monitors once which I brought back to life by changing the capacitors. About half the caps were obviously blown (the tops bulged upwards and goo spilling out. The problem was the other half though. They looked ok on a visual inspection but were in fact equally dead.
Just get a big bag of caps from your local electronics shop and replace them all. It's definitely worth doing because once completed the PBX should effectively have a new life. However if you buy another working PBX it might only be a few months before the old caps in that one start failing.
It's funny that if I leave it off for long enough, it will run for a long time before it goes into power failure mode. It makes me suspect that it has something to do with the 10,000 mfd capacitor in the power regulator. That one takes a really long time to discharge.
You could well be right. It sounds logical to me. Try changing that one and see what happens then.
I replaced the 10,000 mfd capacitor and the two 6,800 mfd ones in the power regulator and I've been running the pbx for almost 5 hours so far without any problems. I'm going to keep it on overnight and see if there are any changes. This is the longest it's been working since I got it so it looks promising.
Fingers crossed those were the culprits, like I said before, they can look fine on the outside, but be dead (or almost dead) on the inside... :)
I think I can safely say now that I think it's fixed. It's been running for 20 hours with no problems. I'll keep running it for a while more just to be really sure.
I have a tip for anyone else that needs to replace capacitors in a 616. Take measurements of the old capacitors so you can order ones that you're sure will fit. I made the mistake of not doing that so I had to be creative installing the new ones. I had to install one horizontally, otherwise it would have stuck out too much for me to put the front panel back on.
Thanks James, I have a couple 616s that need work. Your experience gives me hope I can fix mine.
I'm glad I could help. The only other thing I would recommend is don't use lead free solder. I tried lead free solder years ago and could never get a decent solder joint with it, so I went back to 60/40 rosin core solder.
Quote from: James on November 06, 2017, 03:01:38 PM
The only other thing I would recommend is don't use lead free solder. I tried lead free solder years ago and could never get a decent solder joint with it, so I went back to 60/40 rosin core solder.
Never used it in that it requires a higher temperature (188 vs 220 degrees F) melting point, and I think (IIRC) it also needs a special flux.
Melting point is a function of the metals used and their concentrations in the mix. They use a really low melting point solder (Wood's metal) to capture crystals in it for crystal radios, almost hot water temperatures with it 158° melting point.
Nothing better than 60/40 rosin core for electrical and tin lantern work except today's price for a 1 pound spool.
That explains why it never worked for me. I remember reading somewhere that it can also develop tin whiskers over time.
I've used tin solder in the past and I hated it, never worked right, never flowed properly (bearing in mind I wasn't going to buy a new iron just for a new type of solder that nobody in their right mind would use!!), went right back to proper 60/40 leaded solder, it just works... :)
Thermal stress cracking is an issue for tin solder too, it's a problem a lot of modern electronics suffer, particularly ball-grid array chips, such as integrated CPUs, graphics chips and general integrated circuits used on various modern electronic things, where you can't even get to the solder to reflow it by hand and have to use careful and directed heat to get the solder to melt, reflow and reconnect, and if that doesn't work, you have to remove, clean and re-ball the chips to get them back in, all very fiddly work and requiring some expensive equipment...
And the tin whiskers, that's been known about for years, particularly where metal pins or contacts have been tin coated, but not covered with solder, resulting in the growth of crystalline tin oxides that are conductive, and when they reach an adjacent pin, POP, there goes your component...