PSR-500 wacky problem resolved

[texasemt13]

Folks, I wanted to pass on a problem I was experiencing with my PSR-500 over the past 24 hours. It is resolved now, thank goodness.

Explanation: A few days ago I started noticing that when pressing the backlight button, the light would take a few button presses before illuminating. I figured, no problem, the backlight might be going out. However, yesterday afternoon the situation worsened as my backlight would not illuminate while pressing the key at all, but would light up when I pressed any other key. The situation only got worse. As I turned the scanner on and off (replacing power sources from different battery packs to a wall-wart also) the scanner would show the boot up screen then go straight into the "Prog>Glob>Light" menu. Any key I pressed would not function (including soft keys) but would illuminate the backlight (or turn it off). A few times I was able to start the scanner normally by holding "Pgm" during startup. I was able to load another win500 program from the computer. But all these would start in the the backlight menu also.

Resolution: On the advice of another member, I disassembled the unit to check on the keypad (I've disassembled this thing plenty of times to fix other issues). Once removed I could see that the metal backing on the rear of the keypad (seen below in picture 1) was flaking off on the most used buttons. I could also see on the PCB board where the keys would make contact, that a small flake was centered on the "light" key making contact with the twist (as you can see "flake-less" in picture 2). This small flake was causing a continuous connection to be made to the light key (and was causing all the above associated problems). I promptly removed the flake with some high pressure air, and cleaned the other flakes off the PCB board. I then tried to gently remove the flakings off the back off the keypad. After reassembling and turning back on, the scanner is working perfectly. Might be time to order a new keypad though.

 

[tobarger]

Thanks for taking the time to share your experience.
I haven't had to disassemble my PSR-500 to this degree yet but eventually I'm sure I will have to.
Always good to know what to expect ahead of time.
Nice pictures, they speak 1000 words.
Looks just like a TV remote control only alot more expensive.

 

[scannerhead]

PSR-500 Keypad problem

Agreed. The pictures are great and show what we were talking about in this thread... http://forums.radioreference.com/gre-scanners/173245-psr-500-keypad-issue.html
Depending on which key is being affected will make a difference on the weird behavior of the scanner. I ordered a new rubber keypad from GRE (under $10... shipping was more than the keypad) and that fixed it.

Keith

 

[DaveIN]

Folks, I wanted to pass on a problem I was experiencing with my PSR-500 over the past 24 hours. It is resolved now, thank goodness.

Explanation: A few days ago I started noticing that when pressing the backlight button, the light would take a few button presses before illuminating. I figured, no problem, the backlight might be going out. However, yesterday afternoon the situation worsened as my backlight would not illuminate while pressing the key at all, but would light up when I pressed any other key. The situation only got worse. As I turned the scanner on and off (replacing power sources from different battery packs to a wall-wart also) the scanner would show the boot up screen then go straight into the "Prog>Glob>Light" menu. Any key I pressed would not function (including soft keys) but would illuminate the backlight (or turn it off). A few times I was able to start the scanner normally by holding "Pgm" during startup. I was able to load another win500 program from the computer. But all these would start in the the backlight menu also.

Resolution: On the advice of another member, I disassembled the unit to check on the keypad (I've disassembled this thing plenty of times to fix other issues). Once removed I could see that the metal backing on the rear of the keypad (seen below in picture 1) was flaking off on the most used buttons. I could also see on the PCB board where the keys would make contact, that a small flake was centered on the "light" key making contact with the twist (as you can see "flake-less" in picture 2). This small flake was causing a continuous connection to be made to the light key (and was causing all the above associated problems). I promptly removed the flake with some high pressure air, and cleaned the other flakes off the PCB board. I then tried to gently remove the flakings off the back off the keypad. After reassembling and turning back on, the scanner is working perfectly. Might be time to order a new keypad though.

Jut to be sure, was this material coming off the contact pads, or the PCB itself?

 

[tobarger]

These conductive "flakes" always come from the backside of the keypad buttons.
You can tell from the top photo which buttons on this particular scanner are most used.
In this case the UP and DOWN arrows, FUNC, MAN, SCAN and BACKLIGHT keys.
The whitish areas are where the conductive material has flaked off.
The more a particular button is used, the sooner it will begin to flake.
The only solution is to cleanup the flakes and replace the keypad.

 

[texasemt13]

Jut to be sure, was this material coming off the contact pads, or the PCB itself?

tobarger hit it on the head. It's the metallic backing on the back of the rubber keypad itself, that is flaking off and causing a constant circuit to be created (instead of the instantaneous one required for a button command).

scannerhead- thanks, I hadn't seen that thread. This is definitely the issue. My scanner has been working fine since, but this reminds me I need to call GRE.

 

[krokus]

I just posted a reply in the other keypad item, that lists two options for repairs of the keypads.

http://forums.radioreference.com/gr...500-keypad-issue-post1298904.html#post1298904

 

[texasemt13]

I just posted a reply in the other keypad item, that lists two options for repairs of the keypads.

On it now.

 

[Oldglide]

Can you help with this problem?

You've obviously had your head inside your 500 as much as I have. 1) most electronic stores and suppliers have a conductive coating to fix this problem without buying a new keypad. I have a 500 that works perfect but the display has gone berserk, mirror image, upside down, upside down mirror image, weird characters etc. Do you know of a power reset for the CPU, powering up, down in some sequence? 0,1,ent doesn't help. I posted a new topic called "Power reset for a PSR 500" If you have any suggestions please respond to that topic. Try MCM for the coating for the keypad. Thanks.

 

[tobarger]

Power-On Resets

Here are the three power-on reset sequences taken from the PSR-500 User Guide:

The following table lists the power-on key sequences available in the PSR-500.
Each sequence is invoked by pressing and releasing each key in sequence, one at a time.
The first key must be pressed while the Welcome/Owner screen is being displayed:

0, 1 Destructive, clears working memory and resets all Global settings to factory defaults. Does not affect V-Scanners.

0, 2 Destructive, resets all Global settings to factory defaults. Does not affect working memory or V-Scanners.

0, 5 Destructive, executes EEPROM memory test, then clears working memory and resets all Global settings to factory defaults. Does not affect V-Scanners.

 

[Eng74]

You've obviously had your head inside your 500 as much as I have. 1) most electronic stores and suppliers have a conductive coating to fix this problem without buying a new keypad. I have a 500 that works perfect but the display has gone berserk, mirror image, upside down, upside down mirror image, weird characters etc. Do you know of a power reset for the CPU, powering up, down in some sequence? 0,1,ent doesn't help. I posted a new topic called "Power reset for a PSR 500" If you have any suggestions please respond to that topic. Try MCM for the coating for the keypad. Thanks.

The last firmware update had a fix for the mirror image problem. Have you done the newest firmware update?

 

[grumpy_hermit]

Try MCM for the coating for the keypad. Thanks.

Is this what you are referring to?

Rubber Keypad Repair Kit

 

[Oldglide]

One of the many

There are lots of these type of repair kits available. You might find some cheaper on flea bay. Good luck.

 

[grumpy_hermit]

There are lots of these type of repair kits available. You might find some cheaper on flea bay. Good luck.

OK, thanks. I generally avoid eBay unless the price is dramatically lower.