PSR-500 keypad issue

[captaincraig44]

So in the last week or two, my 500 has become plagued by what appears to be a stuck key. It's intermittent and I can often remedy the condition by pressing hard on the down arrow (it's the up arrow that appears to stick). When the key, or the contact at least, sticks, the radio will be essentially unusable. It won't stop on any transmissions and you can't change anything in any menu. I just wanted to see if there was anyone else that has come across this issue and if there is a simple DIY solution to it before I ante up and send it to GRE.

 

[SCPD]

So in the last week or two, my 500 has become plagued by what appears to be a stuck key. It's intermittent and I can often remedy the condition by pressing hard on the down arrow (it's the up arrow that appears to stick). When the key, or the contact at least, sticks, the radio will be essentially unusable. It won't stop on any transmissions and you can't change anything in any menu. I just wanted to see if there was anyone else that has come across this issue and if there is a simple DIY solution to it before I ante up and send it to GRE.

You could attempt to clean the contact(s) with rubbing alcohol, but most likely your contact has gone bad.

 

[markab]

How do the keys comparw

Hi Captain,
How does the up arrow feel in relation to the other arrow keys? Does it require the same amount of pressure to close the contacts? Does it bounce back as sharply as the other arrow keys? And finally, have you ever spilt any liquids on the scanner? I've never had my 500 apart before, but given the feel of the keys I believe the keyboard matrix uses a pc board with a series of individual thin flexed pieces of metal for each keyboard button. This design can be both difficult to service and clean.

Mark

So in the last week or two, my 500 has become plagued by what appears to be a stuck key. It's intermittent and I can often remedy the condition by pressing hard on the down arrow (it's the up arrow that appears to stick). When the key, or the contact at least, sticks, the radio will be essentially unusable. It won't stop on any transmissions and you can't change anything in any menu. I just wanted to see if there was anyone else that has come across this issue and if there is a simple DIY solution to it before I ante up and send it to GRE.

 

[radiowatcher_06]

Had the same thing happen with my 500, but it was the "down" arrow key. I just took mine apart real quick and cleaned the board and all is good. Inspection of the keypad showed a lot of carbon wear and tear (I think its carbon). I will need to get a new keypad soon if I still want to use the "down" arrow key because of the wear on that little carbon pad.

 

[scannerhead]

Fix from GRE

My PSR-500 became inoperable with the display changing at a frantic pace. My first thought was that the processor had gone bad or the firmware became corrupted. After thinking it through I realized a key was stuck on. No keys were depressed so I opened up the radio. (If your scanner is still under warranty you would want to call and send it to GRE. Or if you are not handy working with radio internal parts, send it in.) The keys have an electrical grey colored "paint" on the bottom of them. When pressed, this "paint" completes a connection on the circuit board. The paint was flaking off of several keys with the UP, Down, MAN and SCAN keys being the worst. The paint was then sticking to the circuit board contacts and continuously making contact.

I ordered a new keypad from GRE. It was approx $7 but the shipping was about $12. They were great to deal with and I received the keypad in a few days. I blew any remaining debris off the board with some compressed air, installed the new keypad and my PSR-500 works like new.

At that time, GRE reps were surprised about my problem and said they hadn't had any other reports of it happening. My old Pro96 never has had the problem. I do use WIN500 for programming but admit I have done alot of button pushing. Anyway, it was an inexpensive fix and I never had to give up my scanner while waiting for repair.

Keith

 

[captaincraig44]

I got the replacement keypad today. However, I noticed before I even opened up the case that the arrow keys were more rectangular than oval. Turns out they entered it into the system correct as a PSR-500 replacement keypad, but I apparently got a PRO-106 replacement pad, and it won't fit the openings in the 500 case. I did see the "paint" on the backside of the keys and there were a few that were well worn, especially the up arrow and scan buttons. Easy enough to open the case and replace it anyway.

 

[ratboy]

Is your 500 one of the early ones? If so, it would be about the right age to begin showing keypad issues if used a lot. In the past, when I had my Pro-43, probably the most used scanner I have ever had, I was wearing out keypads about once every 18 months or so. I wish they would just quit using the carbon button/paint method and go to the sponge method like a lot of computer keyboards use. I have a keyboard that's 20 years old and it looks horrible, the lettering on many keys is gone, but it functions perfectly.

 

[krokus]

Repairing the failing conductive coating is pretty simple, and inexpensive.

There are "rubber keypad repair" kits available, just use the search engine of your choice to find them. I have purchased one, only to find out it's a "one-time use" system, that is basically a conductive epoxy, without a good way to re-seal the components.

The way I have used the most, which has been on a lot of consumer electronic remote controls, was to use aluminum tape. After disassembly, clean the contact side of the rubber sheet, allow to dry, and apply small sections of the tape. That repair should outlast the rest of the radio.

I'm more likely to replace the keypad sheet in mine due to wearing of the key labels.

 

[texasemt13]

The way I have used the most, which has been on a lot of consumer electronic remote controls, was to use aluminum tape. After disassembly, clean the contact side of the rubber sheet, allow to dry, and apply small sections of the tape. That repair should outlast the rest of the radio.

In the instance of the PSR-500 (I dealt with this problem yesterday here) I would not recommend this. My metal flaking was on the order of 1/64th of an inch thick (maybe not even that thick; if I could find a flake I'd go measure it with some calipers- it was that small) and was causing horrible problems by creating a circuit on the PCB board. Aluminum tape would be way too thick to remedy this situation. The keypad sits way too close to the PCB board to squeeze any tape in. The reverse of the buttons (the metallic side) is not recessed very much to allow for the thickness of aluminum tape.

I do like your conductive epoxy suggestion. I'll look for one of these repair kits.

 

[inigo88]

Resurrecting this old thread since my PSR-500 just suffered the same fate, GRE America is long gone and it's looking doubtful that Whistler will do anything to help us out.

My up arrow got stuck, so I took the scanner apart and sure enough there was a tiny flake of the graphite conductive paint that had gotten lodged between the concentric pcb traces and shorted the button out. I was able to clear the flake and clean the pcb traces with a q-tip and isopropyl alcohol, and the scanner works again - but this will just be a temporary fix.

I'll look into some of the rubber keypad repair kits (examples here and here), but it's pretty embarrassing that a $500 scanner would use such cheesy 1980's remote control manufacturing techniques.

Here are some photos of the underside of the rubber keypad with the flaking conductive paint, along with the short on the pcb traces. Hope this helps fellow PSR-500 owners!