How to quickly fix a SANGEAN PR-D5 Power Button malfunction -- and other easy fixes

The Sangean PR-D5, an excellent MW/AM and FM mini boombox radio.

About two years ago I bought a Sangean PR-D5, which I have mentioned several times on several posts here on this blog. I have a blog post about the radio, describing a slight modification I did to my PR-D5 to add a mono jack for better headphone volume, where I also describe the qualities of the radio.

It is an excellent radio -- my best overall performer on MW/AM, and it is very pleasant to use to listen to FM stereo. I use mine for several hours every night while creative writing.

About half a year ago or so, I noticed that sometimes when I hit the power button, the radio would not turn on as instantly as it used to. At first, I ignored it. Then, I tried changing the batteries, thinking perhaps lower voltage messed with the button function somehow -- lower voltage can cause the SiLabs DSP IF chip to not want to fire up, according to the SiLabs datasheet.

Switching to new batteries helped temporarily.

Then after a couple weeks the issue cropped up again. I squirted tuner cleaner down the sides of the power button. It seemed to help, but perhaps it was just me thinking that. The glitch would still happen now and then: I would hit the power button, and the radio would turn to the 'Alarm' setting function. I would hit the power button again, and the radio would turn on.

Finally, I did some research. There is one other guy who mentioned in a review that his STEP/BAND button will sometimes not switch bands but instead will switch stations in memory -- it is as if when he hits one button, the radio thinks he is hitting a different button in the lower row.

That was the same issue my radio had, except when I hit the Power button the radio thought I was hitting another button in the top row -- the 'Alarm' button.

The fact we both were having some button malfunctions -- but the buttons still actually worked -- pointed to a firmware issue, instead of a physical button issue.

THE PROBLEM ISN'T THE BUTTONS THEMSELVES

The buttons themselves still feel solid -- just as solid as they did the day I bought my PR-D5.

As for the buttons, they are installed in a button plate, that is secured to the front panel of the radio, which you can see in this Sangean photo of the CLEAR PR-D5:

Here you can see the button plate, secured to the front of the radio. It appears to be one solid plate, with the buttons embedded in it. Clear PR-D5's sure look cool! (Sangean photo)

The button panel is that white plate in the front-center of the radio. It is fairly well secured to the front of the radio.

Naturally, whenever you press a button and something goes awry, you're going to think it's the button itself. But buttons on digital radios like the Sangean PR-D5 are little more than software toggles.

Because the buttons on the PR-D5 actually work, even when they act up, I don't think the issue is the buttons themselves. If they were to stop working, they would be completely dead. But that isn't the case. The buttons themselves are indeed working. When I hit the power button -- something happens. When the guy on that review hit the STEP/BAND button, something happened. The problem is that what happened wasn't what was supposed to happen.

Here you can see the series of buttons used by the PR-D5 (schematic provided by kind courtesy of Sangean). They can be seen in the upper left center of the schematic here (two 'rails', KEY1 and KEY2). As can be seen here, the buttons work off of resistors. The software 'sees' the change in resistance, which is the way it knows which button is pressed. There is very little that can break. If a button breaks, it's not going to work, period. If a resistor breaks, it's not going to work, period. The fact that the buttons work indicates the firmware can glitch if powered up for months, and all it needs is a periodic reboot.

The front buttons on the PR-D5 are a series of switches, that work with resistors. The microprocessor 'reads' the resistance and then performs the function you want the radio to do. I recently was able to receive a schematic of the PR-D5 from Sangean, and as one can see, the 'Alarm' button is right next to the "Power" button. Unless the switch is actually broken (it isn't) or the resistor is broken (it isn't), the problem is the microprocessor's reading the resistance wrong. 

PROBABLY A FIRMWARE GLITCH WHEN RADIO IS POWERED FOR MONTHS

This hints at a firmware problem -- a glitch with the program in the microprocessor that runs the radio. Perhaps when the PR-D5 is powered up for a long time -- whether you have batteries in it for a while, or have the AC adaptor plugged in for a long time, the firmware can act up.

Re-setting the Sangean PR-D5 is as simple as pulling the AC adaptor plug and removing one battery, and letting it sit for maybe 30 seconds. This fixes button glitches -- at least, it has fixed my radio. The extra jack in the center-left of my PR-D5 is the mono headphone jack I installed -- there is a blog post on that minor modification elsewhere on this blog.

RE-SET / RE-BOOT YOUR RADIO!

The other night, when the radio's power button lagged again, I RE-SET MY RADIO.

I unplugged the AC adaptor, and removed a battery, and I gave it about 30 seconds with no power available to the radio whatsoever. As soon as I plugged in the battery, the radio beeped, the readout went through its re-set phase, and then the clock went blank (it does this during a re-set).

Then I plugged the battery back in and tried the Power button.

The radio came on instantly. Just like the first time I fired it up when I got it at the store! And it has come on instantly the past four days since then (there still is a lag for the audio to come up, which is normal -- the SiLabs chip itself takes 110 milliseconds to initialise).

When you RE-SET the radio, it resets everything, except apparently the memories. My 10 memories are still the same after RE-SETTING it.

To ensure you've had a re-set of your radio, you'll be able to tell because you will see a "POWER FAIL" notice on the LCD readout, and you will hear a BEEP when you re-engage the power to the radio. The display will fill with alpha-numerics, and then give you four dashes (with a colon in between them), or the time (depending on whether the time was set). On mine, because I don't have the clock set, I get a " - - : - - " on the LCD readout when done resetting my radio.

So far, my PR-D5 has no new power button issues. There is no lag before it fires up.  It doesn't show the 'alarm set' icon on the display.

My guess is that the radio needs to be RE-SET now and then. The 'brain' needs its registers cleared.

So, if you are one of the people whose PR-D5's (or PR-D15's, for that matter) have buttons that act up, try RE-SETTING your radio by pulling the AC adaptor plug from the side of the radio, and pulling out the batteries (or even one battery), and give it 30 seconds or more. This fix might work for other similar Sangean and Sangean-made radios with SiLabs chips inside.

I still think the PR-D5 is an excellent MW/AM and FM radio, and worth the money. It seems to be solidly built, and I use mine every night. I would recommend it to any MW/DXer or person who wants a good radio to listen to AM and FM stereo on, whether at work or at home.

THE MICROPROCESSOR IS ALWAYS ON, EVEN WHEN THE RADIO IS 'OFF'

We DXers and radio enthusiasts tend to leave batteries in our radios for long periods of time, or keep them plugged into the wall for a long time -- sometimes the radio is seeing power for months. I know my PR-D5 was. It's been plugged in, or had batteries in it for months. This last time around, it had batteries in it, or the AC adaptor plugged into it, continuously since the Solar Eclipse on August 21st, nearly two months to the day.

This means the radio's microprocessor / 'brain' chip is always working, because with these kinds of radios, the microprocessor has to be already working for the radio to be switched on.

The power button on these radios is always 'on', in a way. The brain of the radio is ON so long as the radio is seeing power, and when you press the Power button, the brain of the radio is reading it and then it actually switches the rest of the radio on when you hit the power button. The power function is a firmware function. All the Power button is, is a toggle which the firmware in the microprocessor 'sees' -- and when the microprocessor 'sees' the button pressed, the microprocessor turns the radio on.

It's possible that some radios just need to be RE-SET now and then, and the newer PR-D5's may be one of those radios. The brain, or the firmware needs a short respite, and a re-boot accomplishes that task.

I'm no expert but that's my guess. And so far this RE-SET fixed has worked with my radio.

The Sangean PR-D5 is a bit bassy at times through some headphones designed for extra bass response. I mostly use a cheap set of dollar store headphones that have a flat response. The station the radio is tuned to in this picture, 790 KJRB The Bear, is an active rock station out of Spokane, Washington that comes in very well most nights.

A pic of my mono headphone jack in use. I have another blog post on the easy installation of a mono jack onto a PR-D5, for easier MW/AM DXing -- but I never placed a pic of the jack in use. Here 'tis. :-)

The blog post on adding a mono headphone jack (along with an overview of the PR-D5) can be found here:

https://interrocknation.blogspot.com/2015/10/fixing-sangean-pr-d5s-low-headphone.html

RE-SET MAY HELP WITH OTHER RADIOS WITH SIMILAR BUTTON GLITCHES

RE-SETTING / RE-BOOTING the radio may work with other Sangean and Sangean-built models that have similar button issues (the famous CCRadio is a Sangean-made model, and I've seen at least one review where a guy said the power button on his CCRadio was acting up).

Remember, we DXers usually have batteries in our radios 24/7, or have them plugged in 24/7. Perhaps re-booting the radios now and then help them act better. :-)

USING JUST BATTERIES MAY PREVENT THE BUTTON ISSUE FROM HAPPENING

For those who run their PR-D5's just off of batteries, this malfunction may not happen at all, because I have found that with frequent use, a set of batteries in a PR-D5 lasts maybe 3 weeks at best. If you're only using batteries, every time you change them, you're resetting the radio. That would mean you are re-setting the radio every three weeks or so. This may explain why many PR-D5 users don't have such issues. For those of us who have our PR-D5's plugged in a lot, and also have batteries in the radio -- the microprocessor may be seeing power for months. Hence, a need to re-boot the radio now and then....

A picture of the two shims I cut out of a bottle lid (from a large bottle of protein powder) using a pair of small shrub cutting shears. The shims keep the C cells from moving around inside the battery compartment, which can cause crackles on the low MW band when you move the PR-D5 around, nulling out stations. I have the shims offset because the battery door closes better, without forcing it shut, and they still get the job done. :-)

USE PLASTIC SHIMS TO REDUCE BATTERY MOVEMENT CRACKLE ON LOW MW CHANNELS

The past few evenings I have used the PR-D5 for DXing the MW/AM band for an hour or so, and I've had two new loggings on the lower end of the band, during partially Auroral conditions (590 KSUB Cedar City, Utah; and 540 KVIP, Redding, California).

While turning the radio to null some stations and increase the signals of others I noticed some crackling during movement of the radio. I opened the battery box and found that a couple of the C cells had shifted.

It turns out it was the batteries -- not all C batteries are the same size, and some can move around inside the radio's compartment. I added two small plastic shims inside the back of the battery compartment, and it eliminated the problem. To allow for the battery door to shut without forcing it I set them a little off center of each other. PROBLEM SOLVED.

Overall, this MW DX season has started oddly. I have heard some unusual stations here and there, but the band fades out way early.

FALL FINALLY ARRIVES

The cold weather began to hit at night during the last week of September, but our Autumn here in the Seattle area hasn't started hitting until the last two weeks or so. September gave us some warm weather, with some days in the 70's F -- but the nights started getting cold, more around 45 or so F.

While the good weather held out, I finished up on some yard maintenance, trimming hedges and brush and cutting some tree limbs with an electric chainsaw. The leaves in the hills didn't start turning until about a week ago -- which is about 2 weeks late. But then, the trees greened out about a week late this Spring, so I guess in a way everything is on schedule. :-)

Here are a few pictures from September and early October. I will put more in another blog post later this week:

Earlier this year, in September, the weather was fine enough outside to do yardwork and listen to a football game on my Sony Sports Walkman, while out cutting brush and a few tree limbs. I had the Sony Sports boombox blasting the game on my front porch, also.

The leaves on an ornamental maple just outside the office I work in, in Seattle. Within a week they were gone, because of wind.

The Oregon Big Leaf maples alongside the Cedar River Trail were more colorful. I took this pic about a week ago. Fall has finally arrived, about a week or two late.

I put up my Mickey Mouse pumpkin early this year.

The leaves are beginning to turn on the trees alongside a muddy Cedar River. Photo taken one week ago, on a Canon digital snapshot camera.

A pumpkin from Halloween 2016.

I hope this article may help some Sangean PR-D5 owners, and I hope all you PR-D5 aficionados out there have a good DX season in the Northern Hemisphere. Also, hope all of you are having a good start of your holiday season. Here in the U.S., Halloween beckons!

Ball Cat says have a great Autumn!

CC 10-27-2017

Addendum, 10-29-2017.
So far the 'fix' for my PR-D5 is still holding -- my power button still works excellently. I am certain that the re-set/re-boot solved the Power button issue on my radio.

Addendum, 11-2-2017.
So far the fix is still working. The power button still goes instantly on.

Addendum, 11-7-2017.
So far the fix is still working. I'm 99% certain re-booting the PR-D5 solved the issue.

Addendum, 11-16-2017.
Fix is still working.... Hope all are having a good November.

Addendum, 5-27-2018.
I added a little clarification to the caption under the schematic, to make it easier to understand how the buttons on the radio works. Also, I have re-set my radio probably twice in the eight months, when I noticed small lags in the radio firing up after pushing the power button. It clears the problem for a few more months.... I still use the PR-D5 nightly and have had no other issues with the radio. :-)

ADDENDUM, 4-20-2022.

I have had this same Power Button issue with my Sangean PR-D14, a radio which is quite similar to the PR-D5, both in performance and operation. A re-set (pull the batteries, pull the AC plug, wait a minute or so, plug back in, making sure all the characters on the LCD display light up and the radio beeps) fixed the problem.

In the case of my PR-D14, the Power Button would tune the radio down a frequency instead of turning the radio off. A second or third push would turn the radio off. Re-setting the radio fixed it.

As with my PR-D5, I was using my PR-D14 a lot and had it either running 24/7 or always plugged in.

To me, these Power Button issues are minor, and easily fixed with a re-set. They probably aren't encountered by most PR-D5 and PR-D14 users. 

I would still recommend these radios to anyone who wants an AM DX radio with excellent FM performance (and in the case of the PR-D5, it's a stereo mini-boombox!).