Pro-162 Display Problem-Again

[Engine104]

Hi Guys,
Last year, I posted about a blank display on my Pro-162. The display came back on several days later and it was fine for the last year. Now, as you can see in the photos below, it intermittently goes from blank to scrambled letters. I took the radio apart and checked and cleaned the solder joints where the display is connected to the circuit board (There is no ribbon cable on this handheld). I inspected all of the solder joints with my jeweler's magnifying glass and by trying to see if any connection was loose, but it appears to be fine. The radio receives fine, but the display issue remains. I may try to go over all of the display board solder joints with my iron just in case. Any ideas would be appreciated. Thanks.

 

[Engine104]

Follow Up..I am thinking this a capacitor issue. I left the batteries out overnight and this morning the display is back to being fine. Has anyone else had this happen with any handheld scanner?

 

[KE5MC]

Leaving batteries out suggests a temperature related issue to me. Normal operating temperature with batteries in heating up circuit boards. Hairline cracks can be very hard to spot. Hair dryer and freeze mist might be a good avenue to pursue to make the problem come and go.
Best of luck!

 

[Engine104]

Leaving batteries out suggests a temperature related issue to me. Normal operating temperature with batteries in heating up circuit boards. Hairline cracks can be very hard to spot. Hair dryer and freeze mist might be a good avenue to pursue to make the problem come and go.
Best of luck!

That could be. I'll give that a try. Thanks!

 

[crazyretrotech]

likely not as your seem scrambled and as you stated did it and worked for a year? I would still double check the flex going to the display, older ones used a FPC connector towards top and reseating it typically resolves issue, later one if I remember used conductive glue and you need to heat the flat flex to board connections. If no change then something like a failing capacitor, as can be affected by temperature. It could be a dodgy connection, or hairline crack as others stated, but then you have to heat and cool the board to find crack, or dodgy connection, or failing component. The display flex is also affected by temperature as had older one with FPC on top the connection get oxidized over the years do similar behavior with scrambled charctors and even display completely when out, I had to trim edge of flat flex put back in FPC and work fine for 2 years afterwards. Worst it could be the display controller going bad? The fact it worked for a year kind of odd

 

[tvengr]

Solder connections in a scanner that old are a common problem. A solder connection can be bad even though it looks OK. Metal expands and contracts with temperature change and can cause a solder connection to fail. I suggest reheating all of the solder connections going to the display and adding a dab of new solder. It could be a solder connection to any components feeding the display. You can try flexing, heating, and chilling the circuit board to locate the area of trouble. Electrolytic capacitors are the most likely components to fail.

 

[Engine104]

Thanks Tvengr..The display is now out completely. A week or so ago, I went over all of the solder connections with my iron, but that didn't help. I have a feeling it is a capacitor that's gone bad.

 

[Tim-Elyria]

In the past i have had luck cleaning up the connection where the display attaches to the board with the small rubber like pads( connector strips ) between the display and the PCB

 

[tvengr]

Your problem could still be a solder connection somewhere on the circuit board. It has been my experience that solder connections on circuit boards tend to fail after about 10 or 15 years. Try heating the circuit board with a hair dryer. If the display comes back, try hitting components with chill spray to see if it goes out again. You can try pressing and pulling up on components to see if it makes a difference. You may find a lead pulls out. Just be careful not to disturb coils or any other components which could affect tuning. We had several hair dryers in the maintenance shop at our TV station. You can't imagine some of the comments I received from reporters when they saw me working on a studio camera in the newsroom using a hair dryer. Heating and chilling is a common method of servicing electronic equipment.

 

[Engine104]

Thanks so much. I'll give that the hair dryer a try.

 

[tvengr]

Another note: Old electrolytic capacitors can drastically change value with a change in temperature. Equipment will start or stop working as it heats up.