PRO-95: Two Issues

[a1rusty]

My PRO-95, which I have used and abused for the last 3 or 4 years, has developed 2 unrelated (I think) issues, which I would love to get some advice on addressing.
1) When I first got it, I programmed a bank for the Richardson, Texas, EDACS system. It worked great on my infrequent trips there, but some months ago, the audio went silent. It still scans, and still shows talk group information when it locks onto a transmission.... but no audio. The kicker is, that if I go to manual and step through the freq's, I get the audio fine when I happen to hit an active channel. I'm not aware of making any changes to the programming, and the RR database has the same data it always had... so I am frustrated! The scanner works great on Motorola trunked systems. And... speaking of manual operation:
Issue 2) From time to time in manual mode, the scanner just dies. Display goes blank, nothing comes through, except that the audio section apparently still works, because rotating the volume knob gives me the dirty-potentiometer scratchy noise.
Any ideas? And I know, I've gotta replace it with a digital unit eventually, but I'm going crazy over the GRE vs. RS discussions. The two scanners are so different, I can't decide which one is right for me! And I can't afford to buy both! HELP!

 

[gmclam]

Pro-95

My PRO-95, ... 1) When I first got it, I programmed a bank for the Richardson, Texas, EDACS system. It worked great on my infrequent trips there, but some months ago, the audio went silent. It still scans, and still shows talk group information when it locks onto a transmission.... but no audio. The kicker is, that if I go to manual and step through the freq's, I get the audio fine when I happen to hit an active channel. I'm not aware of making any changes to the programming, and the RR database has the same data it always had...

My first thought - are you sure the channels in the PRO-95 are still programmed as they were the last time you used it successfully? Are ALL of the channels still programmed to EDACS? Assuming there were no changes to the system (you could check with folks in the Texas forum here), I'd debug this as if you never had it working in the first place. As you know, you can hear what is on a frequency in MAN mode regardless of the MODE setting; but everything (control channel, bank, voice channel) has to be set correctly for it to trunk track.

2) From time to time in manual mode, the scanner just dies. Display goes blank, nothing comes through, except that the audio section apparently still works, because rotating the volume knob gives me the dirty-potentiometer scratchy noise.
Any ideas?

I am not sure what you mean exactly by "dies". What is your power source? Is the power source "solid" when it dies? Some of the symptoms sound like a bad squelch pot, except for the display going blank. I wonder if it would "die" if the display backlight is on... or if the display backlight would remain lit??? This would be one way to determine that the scanner is still getting power when the display goes out.

 

[a1rusty]

Pro-95

Thanks for the reply, gmclam... much appreciated.

My first thought - are you sure the channels in the PRO-95 are still programmed as they were the last time you used it successfully? Are ALL of the channels still programmed to EDACS? Assuming there were no changes to the system (you could check with folks in the Texas forum here), I'd debug this as if you never had it working in the first place. As you know, you can hear what is on a frequency in MAN mode regardless of the MODE setting; but everything (control channel, bank, voice channel) has to be set correctly for it to trunk track.

I'm pretty sure the channels are still programmed as they were originally, because it still tracks the Richardson system... that is, it stops on an active channel, displays the frequency and the talk group id, then after about the right time for a transmission, goes back to scanning... but no audio. Really weird, huh? The problem only occurs on the one and only EDACS system I have programmed... it scans the four Motorola trunked systems I have in it just fine.

I am not sure what you mean exactly by "dies". What is your power source? Is the power source "solid" when it dies? Some of the symptoms sound like a bad squelch pot, except for the display going blank. I wonder if it would "die" if the display backlight is on... or if the display backlight would remain lit??? This would be one way to determine that the scanner is still getting power when the display goes out.

By "dies", I mean it looks like a complete loss of power.... except, you can still hear a scratchy noise through the speaker when you rotate the volume knob.... this is on battery power... haven't tried it car battery power... but it only happens in manual mode... never in scan mode; and, when it happens, turning it off and back on restores normal operation, although it may or may not "die" again. But again, only in manual mode; if you go back to scan mode, everything works like it should.

Whatcha think?

 

[gmclam]

Broken PRO-95

...that is, it stops on an active channel, displays the frequency and the talk group id, then after about the right time for a transmission, goes back to scanning... but no audio. Really weird, huh? The problem only occurs on the one and only EDACS system I have programmed... it scans the four Motorola trunked systems I have in it just fine.

I've only programmed and listened to one EDACS system on a PRO-95, but if I am thinking correctly; you have to put in all of the frequencies of the trunk and they have to be in the correct "slots". The scanner monitors the control channel, and switches to the correct "slot" to get the voice communication. Now if the channel/frequency in that slot is set for AM (or perhaps even MO), then I wonder if you'd experience what you're (not) hearing. ?

By "dies", I mean it looks like a complete loss of power.... except, you can still hear a scratchy noise through the speaker when you rotate the volume knob.... this is on battery power... haven't tried it car battery power... but it only happens in manual mode... never in scan mode; and, when it happens, turning it off and back on restores normal operation, although it may or may not "die" again. But again, only in manual mode; if you go back to scan mode, everything works like it should.
Whatcha think?

This sounds like the CPU is crashing. What it sounds like is the power (or some other critical signal) is being interrupted to the CPU and it crashes. The CPU runs the display, and sets signals to enable you to hear a transmission. But of course the audio amp is still powered. The most likely things that will cause this condition are PHYSICAL connections - battery contacts, power jack, power switch, interconnects on PC boards. It could be a power or ground circuit. I repaired a PRO-92 not too long ago that turned out to have a loss of ground to one of the circuit boards. It was a weird one.

Did these 2 issues start at the same time? Perhaps they're related. If all of the programming is absolutely correct, then I'd be looking at interconnects within the scanner. The EDACS silence could be either the squelch circuit not opening or perhaps AM mode selected (although whenever I've had AM selected on an FM signal in these scanners I don't get silence).

If you have any more clues that might help. Also, you could download the scanner's contents with WIN95 and send me the file. I can look at it and/or program it into a '95. I know I can't receive the system here, but I might see something. Just thoughts.

 

[SCPD]

get win95, save your stuff, then do a complete reset of the scanner & try again? perhaps

 

[a1rusty]

Pro-95 Issues

gmclam & AlabamaRS: Thanks for your thoughts & recommendations. They have helped me greatly in deciding how to work around these two problems. Regarding the Richardson EDACS system (BTW, I do program my Pro-95 with Win95), I think I'm going to buy a cheap 800 MHz conventional scanner and program it with the Richardson freq's, except for the control channel, which I will leave out. I know I'll lose the talk group ID info, and it won't track responses, but no more frequently than I'm in the Richardson area, I can live with that.

As far as the manual mode shutdown issue, I agree with gmclam that it's probably an intermittent short or open on the circuit that controls manual mode. My solution is just to leave it in scan mode, where it works fine... again, using Win95 for any programming changes.

Thanks again to both of you for taking the time to think about this and for your responses. Definitely helpful.

 

[NoNeOfYoUrBiZnEsS]

I had the same problem and all i did was replace the batteries and the problem went away.
The weak batteries may have messed up your edacs too.

 

[a1rusty]

Well, I use rechargeable batteries at the house, and car power while mobile, so I don't think that's it. But thanks for your reply... every bit of information helps... if not with this problem, with the next one... and there WILL be a next one!