[Pro2006] What to do!

[Bob Whiston]

At 21:32 15-06-04, you wrote:
>Hello Laird and other fans of these great Radio Shack scanners,
>
>1.  I have a couple of Pro-2004s that don't work, and display some weird 
>symptoms.  When he was alive, Bill Cheek emailed me that many of the 
>problems were related to bad soldering on the motherboard.  I got the 
>scanners used, and it looks like someone has tried some repair or 
>modification of the radios.

         OK...  The PRO-2004s suffered from a bit more than *just* `poor' 
solder jobs.  They also have poor through plated holes on the assorted 
circuit boards.  (I've got a pair of them myself and have `fought with' 
them quite a bit over the years.  I also finally just through in the towel 
a couple years ago and basically let both of them `die' and went and dug 
out a pair of 2006s I had stashed away.  I figured that until I could 
actually get a *real* `repair bench' back up and running, having children 
and needing that `spare bedroom' that was originally one's `lab' is *where* 
my `lab' went, I could `get by' for a while.  {WAN GRIN!})  Anyway...  What 
you will need to be able to do is first get youself both a good schematic 
*and* board layouts.  Next...  You will have to *CAREFULLY* go through 
*each* board, starting with the power supply section then proceding to the 
audio section, and then the digital section, and finally the RF section, 
*CAREFULLY* wiggling all the wires followed by all the `wired' components 
noting the results.  Put a marker on those points where you find a 
problem.  After you've got a board full of markers the next thing will be 
to carefully touch-up the solder joints on those points taking care to keep 
from overheating whatever it is you are resoldering.  This phase will 
probably entail several passes through before one can be halfway assured 
they have gotten all those bad spots.  Be especially careful about getting 
*both* sides of each connection!  (Remember I mentioned problems with 
through plated holes!)

         OK...  Now that you've pretty much taken care of *most* of the 
`problems' it is time to go after the next set, `sour traces'.  For these 
this is where having access to *both* a schematic and board layouts come in 
handy.  The main places *I* found `sour traces' were between 
interconnection `cables' and components.  IE: A ribbon cable is attached to 
the board in one place but it doesn't go directly to the components it 
shows on the schematic and instead goes to a set of `pads' that then have 
traces that *do* go to the components.  (One of my 2004s actually has about 
1 & 1/2 dozen jumper wires with `micro-clips' running from either cable to 
component or bypassing the cable and going directly from component on one 
board to component on another board!  Amazingly enough I actually managed 
to get quite a few years of use out of it this way and the only reason it 
was `retired' along with it's `mate' was that I was going to use it as an 
example to fix the `mate'. [Just as soon as I could get a `bench' back up. 
{WAN GRIN!}])  Anyway...  I figure that *if* one *takes their time* and 
*carefully* goes through with just the resoldering and installing jumpers 
as needed one can get a 2004 pretty much back up and running in a few 
weeks.  (I say `few weeks' because, as I keep emphasizing, *careful* is the 
`trick'!  You *have* to check out *everything* and not just stop when it 
first flickers back to life because you've gotten the ones that have 
already `gone' and not the ones getting ready to go.)

         After that you can then address the display backlight problem.  In 
both of mine I didn't replace the backlights with new EL panels even though 
I could have done so at the time.  Bill and I had discussed the basic 
problems of the EL panels and it was decided that I would try to see if 
there might be a way to use LEDs instead.  I managed to locate some `milk 
white' plastic that was thin enough to fit where the EL panel was mounted, 
trimmed a couple pieces to fit with some extra sticking out to provide a 
place to mount some LEDs, then I carefully *inset* the LEDs into the 
plastic so that the majority of the light from the LEDs would be difused 
through the plastic.  (One *has* to be *very* careful about getting the 
original panel out from behind the readout *and* also careful that the 
plastic is thin enough to fit back behind because those readouts are 
irreplaceable and one doesn't want to crack them or in any other way damage 
it!)  My first attempt didn't quite fully illuminate the whole display and 
I had to eventually carefully glue some thin foil to the backside to 
reflect back the light that was escaping out the backside.  {GRIN!}  (I 
also tried several different colours of LEDs eventually settling on yellow 
ones because they were the brightest I could find at the time that were 
also small enough.  Today I suppose that one could pretty much choose most 
any colour since they have made some pretty serious advances in LED 
`tech-no-golly' and one can get some very small and bright ones in just 
about every colour.)  The other `route' that one can also take now is 
replacing the EL panel with another one since EL panel `tech-no-golly' 
these days has also made some decent advances and one can get `experimenter 
kits' that one can pretty much cut out whatever size one may need.  Either 
way, just like going through the boards and cables, the operative `word' is 
*still* *carefully*.  As much as you'd like to get that `old friend' back 
up and running as quickly as possible it isn't something to rush.

         Having said all that I've said I think that if one just takes 
one's time and doesn't rush most anyone can repair and get running their 
2004 *unless* one actually is one of those very few that are absolute 
`ditzes' when it comes to basic electronics and soldering.  (If one *is* 
worried about their soldering abilities there actually are still some DIY 
kits out there that one can build first to get some soldering experience 
`under their belts' before attacking something like a 2004!  They, like the 
2004, call for something around a 25 or so watt soldering iron with a 
fairly `small' / `fine' tip along with being patient and not 
rushing.)  Personally I would suggest that one acquire a `soldering 
station' that has the ability to use assorted different sized tips and use 
the smallest tip possible to do the job.  In my case I am used to using an 
UNGAR adjustable temp soldering station but since it's not something that 
one can just go out and buy any old place I'd recommend that one try and 
find something along the lines of a WELLER WLC100 soldering station or 
WES51 `Electronic' soldering station and adjusting either one such that the 
tip you've selected will easily melt the solder without spattering and 
burning.  (These `stations' can effectively give one an iron that can be as 
`light' as 10 watts and as `heavy' as approximately 50 watts depending upon 
both the adjustment and `job' without having to have a whole `collection' 
of irons!  All one has to do is just pick a tip and and then adjust for 
proper solder melting.)  As for solder...  Again, *personally*, I use ERSIN 
`Multicore' solder but, any *quality* .040" dia. *rosin* core solder should 
work.  (It shouldn't take all that much, just a `smiddgen', solder to fix 
most of the joint problems and *maybe* a tiny bit more for some of the 
`heavier' joints.)


>2.  I have some Pro-2006s that have the dim display problem, and need to 
>have the EL panel replaced.  That is a lot of expense and work to do.  I 
>don't have the time to attempt this repair myself.  I was wondering if 
>there is a way to use a couple of LEDs to light the display.

         The 2006s shouldn't be any harder to fix than the 2004s and 
actually could be the first ones you *might* want to `attack'.  All you 
have to do is remember that operative word *carefully* when you go in to 
`diddle' with that backlight.  {GRIN!}  I'd sure hate to hear that you've 
cracked the readout and are now looking for a replacement because you 
resorted to `brute force' to free the EL panel from behind the 
display!  (By now *both* the 2004s and the 2006s `glue' has hardened and 
you *will* have to pick it away, slowly, piece by piece.)

         I'm *not* trying to scare you!  I just want to let you know that 
it *can* be done but, you *do* have to exercise some reasonable caution and 
*not* try and `hurry' things along.  Like Bill used to say...  "Most anyone 
can do this stuff as long as they realize this *isn't* an old `hotrod' one 
is `cobbling together' out under the old shade tree in the backyard using 
the `cowboy', if it doesn't go get a bigger hammer, method."  {VBSE 
GRIN!}  I really wish that I had a bench back up so that I could try and 
help you by working on mine and talking you through the steps as we got to 
them!


---
     Doleo ergo sum,
        Bob Whiston

        "Too late to work within the system, too early to shoot them all."