BAND+ push button failure...
Locked
 
|
I just did the AF-Gain-Control Mod on my older K2 sn 2289. After
reassembly, the gray BAND+ is starting to fail. It is used a lot for KDSP2 programming and does always recognize a push and hold function now. It often interprets it as a momentary push. I could and should just order the new part from Elecraft. I wonder if some contact cleaner spray would help? I have some Radio Shack spray cleaner already. I would like to hear from others on this reflector first. It is odd that the failure started just after completely removing the front panel and reassembling it. 73, Steve N6VL K2/100 sn 2289 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: BAND+ push button failure...
|
|
Steve,
As you said is only started after disassembling the front panel, I would suggest looking for some other cause than the button itself. Check the soldering of the pushbutton well. If you do disassemble the board from the front panel again, you might try soldering the pushbutton from the top - the leads do not stick very far through the holes and it may not have been heated adequately in the initial soldering process. Pushbutton failures are rare. They are sealed, so I do not think the cleaner spray would be effective, but it may be worth a try. If you remove the left side panel, you can get to the edge of the pushbutton without disassembling anything else. The microprocessor interprets the tap/hold selection, not the pushbutton itself - of course the contacts could be bouncing and causing the problem, but a bad solder connection might also behave that way too. Steve Kallal wrote: > I just did the AF-Gain-Control Mod on my older K2 sn 2289. After > reassembly, the gray BAND+ is starting to fail. It is used a lot for > KDSP2 programming and does always recognize a push and hold function > now. It often interprets it as a momentary push. > > I could and should just order the new part from Elecraft. I wonder if > some contact cleaner spray would help? I have some Radio Shack spray > cleaner already. I would like to hear from others on this reflector > first. It is odd that the failure started just after completely > removing the front panel and reassembling it. > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: BAND+ push button failure...
|
|
Don,
I just spent most of the afternoon going over every trace that is part of the connection between the Front Panel, RF, & Control boards looking for solder bridges and frayed wires. Remember this started as a volume control mod requiring cuts and jumpers on all the above boards. That said, I noticed the BAND+ tap/hold works every time if I push the button differently. I normally push the button horizontally, that is towards the rear of the rig. The tap/hold function works every thing if I press vertically towards the bottom of the rig. That makes me suspect the switch is going bad. It doesn't explain why the problem just started after my other volume control mod. I will probably order some switches from Elecraft and see if that fixes it. 73, Steve N6VL Don Wilhelm wrote: > Steve, > > As you said is only started after disassembling the front panel, I > would suggest looking for some other cause than the button itself. > Check the soldering of the pushbutton well. If you do disassemble the > board from the front panel again, you might try soldering the > pushbutton from the top - the leads do not stick very far through the > holes and it may not have been heated adequately in the initial > soldering process. > > Pushbutton failures are rare. They are sealed, so I do not think the > cleaner spray would be effective, but it may be worth a try. If you > remove the left side panel, you can get to the edge of the pushbutton > without disassembling anything else. > > The microprocessor interprets the tap/hold selection, not the > pushbutton itself - of course the contacts could be bouncing and > causing the problem, but a bad solder connection might also behave > that way too. Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: BAND+ push button failure...
|
|
Steve,
That certainly sounds like you have one of those rare occurrences - a bad switch. It certainly can happen - actually most any part can fail at times, but a bad switch is quite low on my list of usual suspects. 73, Don W3FPR Steve Kallal wrote: > Don, > > I just spent most of the afternoon going over every trace that is part > of the connection between the Front Panel, RF, & Control boards > looking for solder bridges and frayed wires. Remember this started as > a volume control mod requiring cuts and jumpers on all the above boards. > > That said, I noticed the BAND+ tap/hold works every time if I push the > button differently. I normally push the button horizontally, that is > towards the rear of the rig. The tap/hold function works every thing > if I press vertically towards the bottom of the rig. That makes me > suspect the switch is going bad. It doesn't explain why the problem > just started after my other volume control mod. > > I will probably order some switches from Elecraft and see if that > fixes it. > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
On Sun, 2008-07-13 at 18:26, Don Wilhelm wrote:
> Steve, > > That certainly sounds like you have one of those rare occurrences - a > bad switch. It certainly can happen - actually most any part can fail > at times, but a bad switch is quite low on my list of usual suspects. > > 73, > Don W3FPR I have a 20-year-old Advantest R4136 microwave spectrum analyzer that I acquired several years ago in non-working condition. The sympton was that every one of the fifty (!) pushbutton switches on the front panel did not work. Initially, I was sure it couldn't be that every switch had gone bad - it had to be a bad interface IC, unseated connector, malfunctioning microprocessor, etc. You guessed it - every single one of those 50 switches had indeed failed. (Confirmed by the fact that I could toggle each switch function by bridging each pair of contacts with a clip lead.) I ended up disassembling every switch, cleaning the internal contacts with a Q-tip dipped in alcohol and reassembling. It took me a couple hours to do all 50 switches. The instrument works great now. Al N1AL _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: BAND+ push button failure...
|
|
In reply to this post by Don Wilhelm-4
Don,
I am about to change my mind. Now I am having a flaky response from the XFIL button, much the same symptoms. I already went through the Front Panel, Control, & RF boards earlier today. Now I am out of ideas. I must of jarred something loose when do the volume control mod. 73, Steve Kallal Don Wilhelm wrote: > Steve, > > That certainly sounds like you have one of those rare occurrences - a > bad switch. It certainly can happen - actually most any part can fail > at times, but a bad switch is quite low on my list of usual suspects. > > 73, > Don W3FPR _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
Steve Kallal wrote:
> Don, > > I am about to change my mind. Now I am having a flaky response from the > XFIL button, much the same symptoms. > > I already went through the Front Panel, Control, & RF boards earlier > today. Now I am out of ideas. I must of jarred something loose when do > the volume control mod. Don probably already suggested this, but I bet you forgot to solder something somewhere. When the board flexes, the connection opens and closes. It doesn't need to be the front panel board; it could be the connectors on the RF board since you said that pushing downward has an effect. It didn't have to be something you did during the mod. An unsoldered connection can work for a long time! -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
In reply to this post by Don Wilhelm-4
The most frequently used push button switches (for me they are BAND+, BAND-, MENU, MODE, XFIL, A/B, A=B) do go bad after a while. I own a pair of K2/100's and I've had to replace all of the switches I've already mentioned on each rig.
I'm friends with a couple of other local hams and they have had to replace some their frequently used switches on their K2's as well. So its not really that rare of an occurrence as they do start to malfunction after a while. 73, Ian - K8MM
|
|
|
Switches do fail, especially if only taking a light current. Advantest spectrum analysers were famous for it. You might try some switch cleaner but replacement may be the only option if the switch is sealed. The other possibility is the solder contacts have failed somewhere through repeated flexing. This may well be completely invisible on inspection. The cure is to re-melt the solder on all the joints. The most likely contacts are those on the switch, but also check the multiway headers.
Mike
|
|
|
In reply to this post by K8MM
Not at all rare on a well used K2!
On two K2s I changed Mode, A/B, A=B, PRE/ATT, AGC, & XFIL and a couple others. The A/B and A=B were the worst (and most frustrating when they would bounce). On one of them a new switch bounces, but only occasionally. I bought 24 switches and have about a half dozen left. 73 Hank K8DD <quote author="K8MM"> The most frequently used push button switches (for me they are BAND+, BAND-, MENU, MODE, XFIL, A/B, A=B) do go bad after a while. I own a pair of K2/100's and I've had to replace all of the switches I've already mentioned on each rig. I'm friends with a couple of other local hams and they have had to replace some their frequently used switches on their K2's as well. So its not really that rare of an occurrence as they do start to malfunction after a while. 73, Ian - K8MM |
|
|
In reply to this post by AD6XY
Reheating the solder joints was the first thing it tried to fix it, but bad solder joints weren't causing the problem. Replacing the switches was an easy fix.
I use my K2/100's almost daily for dx'ing and contesting so they get a very good workout. The only thing I've ever had to fix in 8 years, that wasn't caused by me doing something stupid, was to replace the worn out switches. I can't say the same for my previous radios from the big 3, that's why I have a pair of K2's sitting on my desk. That and the fact they were the only radios that can stand up to the AM BCB overload problem I had at my location with other rigs. Ian <quote author="AD6XY"> Switches do fail, especially if only taking a light current. Advantest spectrum analysers were famous for it. You might try some switch cleaner but replacement may be the only option if the switch is sealed. The other possibility is the solder contacts have failed somewhere through repeated flexing. This may well be completely invisible on inspection. The cure is to re-melt the solder on all the joints. The most likely contacts are those on the switch, but also check the multiway headers. Mike |
«
Return to [K2]
|
1 view|%1 views
| Free forum by Nabble | Edit this page |