Dimming the Pro78/XTR-690's alert LEDs...

[MEM-TEK]

Hi everyone,

Jag42 asked how he could dim his Pro78's alert LEDs to more or less match the brightness of his Pro78's display. Thus this post is to answer his question and to provide info for others who might wish to do the same.

NOTES: OPENING UP YOUR RADAR DETECTOR COULD VOID ITS WARRANTY! THIS PROCEDURE REQUIRES OPENING UP YOUR RADAR DETECTOR. DO NOT DO THIS IF YOU ARE NOT FAMILIAR WITH HOW TO TAKE PROPER PRECAUTIONS AGAINST ELECTROSTATIC DISCHARGE (ESD) OR IF YOU ARE NOT WILLING TO FOLLOW MY SPECIFIC INSTRUCTIONS. ALSO NOTE THAT THE FOLLOWING INFORMATION IS "FOR INFORMATIONAL PURPOSES ONLY" AND THAT I SHALL NOT BE HELD LIABLE IN ANY FASHION REGARDING THE ACCURACY OF THE INFORMATION PROVIDED.

Items which you will need:

-- A 110V AC to 12DC adapter which has a built-in cigarette lighter socket. RS used to sell #273-1675 which is ideal. I don't know if RS still sells this item. Whatever AC to DC adapter which you use, be sure that it features regulated DC output. This is important! The point of the AC to DC adapter is to allow you to easily test this display modification indoors so that you can be sure that you are satisfied with your results.
-- A small PH1 Phillips head screw driver.
-- A large piece of aluminum foil or a large aluminized mylar anti-static bag which has been cut open to expose the anti-static bag's internal aluminized surface. This will serve as the work surface (WS).
-- A Sharpie fine point red permanent marker. (I tried several other Sharpie colors but found that red works the best.
-- Denatured alcohol (toxic, read precautions) and some cotton ear swabs in case you mess up and need to start over or need to "undo" this modification.

Alrighty! Here is how to dim your Pro7/XTR-690's alert LEDs...

Setting up for work:

1. Make sure that you are not wearing any synthetic clothing. All your clothing should be cotton. If you are like Dave, you probably are already naked, which would be ideal!

2. Do not work at a table and/or chair which is atop carpet since carpet is a huge static electricity generator. Instead, work at a table which is on either a hardwood floor or linoleum floor. A table surface in most people's kitchens should suffice since I doubt that you have carpet in your kitchen!

3. Do not work on a glass surfaced table. Any other table is better than a glass surfaced table since glass is a near perfect insulator and can accumulate a very strong static charge.

4. Place either a sheet of aluminum foil or a cut-open aluminized mylar anti-static bag atop your work table. If you are using an opened up mylar anti-static bag, be sure that the insides of the cut-open bag is face up.

5. Plug in your regulated AC to 12VDC power supply and then plug in your Pro78/XTR-690 (RD) power cord. Plug the power cord into your RD so that your RD turns on.

6. Use the Menu button to get into the menu mode and cycle through until you get to the LED settings. Set the LEDs to be always on so that you can check how much you have dimmed the LEDs while you work.

7. Unplug the RD power cord from the RD.

Opening up the RD for the actual display dimming modifications:

1. Set the RD face down atop the aluminum foil or aluminized mylar work surface (WS).

2. Using the Phillips screwdriver, remove the screws on the RD's bottom case.

3. Once the case screws are removed, flip the RD over.

4. While keeping part of a hand or arm resting on the WS, gently lift off the RD's top cover and then pivot it upside down and adjacent to the rest of the RD. As you lift it off and peek inside, you will see that there are two sets of cables between the top case and the RD's main circuit board. One cable is for the speaker which is mounted in the top case, and the other cable is for the push buttons which are also mounted in the top case. The pivot point for flipping over the top part of the case is the side of the RD where the power plug is located. There is no need or reason to touch anything inside while lifting up and flipping over the RD's top case. Yet, if you have kept either part of a hand or arm resting on the WS, then there is no way that you will damage the RD internals via ESD.

Alrighty! You have your RD opened up such that its top case is now resting alongside the RD's bottom case and internal main board and radar horn.

Performing the actual LED display dimming modifications:

First, have a look at where the blue alert LEDs are installed upon the RD's main circuit board:


Here is a close-up shot of where the right alert LED is installed on the RD main board near the power jack:


Here is a close-up shot of where the left alert LED is installed within the shielded chamber for the RD's laser circuitry:


Now, have a look at the plastic light pipes used inside of the RD:


Here is a closeup of the right light pipe (already colored to dim it):


Here is a closeup of the left light pipe (already colored to dim it):



1. Working with just one light pipe at a time, use the red Sharpie to darken the areas as shown for both the left and right light pipes. Don't overdo the amount of application of the red Sharpie color. Use the Sharpie marker sparingly, temporarily reinstall the RD's top cover, plug the RD into its power cord, and then visually inspect how much you have dimmed the particular alert LED which you are working on.

2. If you overdo the dimming of an alert LED, use a cotton ear swab (Q-tip) lightly soaked in denatured alcohol to remove the red Sharpie marks and then start over.

3. While you won't be able to get the alert LED's color to exactly match the color of the Pro78's alphanumeric display, you should easily, by trial and error, be able to get each alert LED's intensity to match the Pro78's alphanumeric display.

Here are the results which I got. Note that, although visually, the alert LEDs appeared to be just as dim as my Pro78's display, my digital camera recorded the intensities a bit differently:


4. Once you are done, and most importantly, make sure that the speaker wires are positioned so that there is no chance that they will get pinched underneath the RD's windshield bracket quick release mechanism as you close up the RD case for the final time:


5. Reinstall the RD's case screws. You are done.

Well, there you have it!

[Jag42]

wow ! I feel special thanks Mem-Tek.

[MEM-TEK]

wow ! I feel special thanks Mem-Tek.

I wanted to come up with something simpler, using colored acetate instead, yet the components of the Pro78/690 fit so perfectly together that there was no other option other than using a Sharpie to dim the light pipes.

[stray444]

If you are like Dave, you probably are already naked, which would be ideal!

haha


Thanks for the post, great read....

[Jag42]

did u try a purple sharpie? seems like it would dull the color to a darker blue. thanks for all the hard work. But if you don't want to worry about static electricity why not strip naked right? LOL

[Whistler1]

Mem-Tek,

After using the Pro78 for a while I have deactivated the voice and LED periscopes on my Detector. I found that at night I was drawing to much attention to myself. I might give the sharpie idea a try although, I concerned about taking the PRo78 apart voidin the warranty. You have already satisfied my curiosity by taking the in your possession apart.

Whistler 1

[Jag42]

I agree i have never opened mine up. but i might give it a try.

[MEM-TEK]

I agree i have never opened mine up. but i might give it a try.

Its no big deal to open it up and have a look inside. Just follow my instructions to avoid ESD. Other than being careful to follow the ESD precautions I mentioned, opening up a Pro78 is a piece of cake. You will even note how easy it is to replace the speaker yourself if the speaker ever blows. The speaker is secured with a clip and a single screw, and the speaker wires have a plug which plugs into the main circuit board.

[Ck15]

i did this with mine except with blue touchup paint i had laying in my glove box