Grundig Satellit 800 Video#1 - Broken Volume Control

I banged the volume control by accident on my Grundig Satellit 800 Millennium causing the volume to stick at maximum. My guess is that the volume control potentiometer has lost it's ground connection and it should be easy to repair. No, not really.

[@michaelcherry8952]

The exemplar of "No User Serviceable Parts Inside" :( I admire your courage in tackling something like this. Obviously Grundig assumed that the radio would be scrapped when something like this occurred. Persistence pays off!

[@seasparrow7427]

Even though I'm watching this later, I'm feeling your pain lol!! And now we all know why there's 2 handles on each end of the front. Protecting the knobs and buttons when you're hooking up the antennas or putting batteries in or out.

[@danielmarkleblanc1800]

Very nice job and Brilliant video on a radio that is dear to my heart.

[@mphilipk]

Jim, enjoyed the video. Not your frustration but your patience. I have the same radio and also broke it - also my fault. I put the batteries in while in the dark and inadvertently put them in backards. Blew something instantly-hoping it is a diode or voltage regulator. I’ll be happy if I can get the back off. :)

[@josemesquita603]

Nice work. The stereo volume potentiometer seems to be defective and needs to be replaced. Remove the potentiometer in order to check it with a ohmeter to find what terminals are broken. While it is removed, check the PCB traces with the ohmeter, as broken PCB traces and cold joints should be easy to find this way. The potentiometer should be easy to find as a spare part. If not, dismantling it carefully to find what is broken inside. I have fixed a few of vintage pots by using small amounts of liquid silver paint close to the terminals rivets.

[@graemedavidson499]

Looking at the schematic, it appears the volume control is a stereo pot. I’d not be surprised if the impact travelled through the shaft of the pot and put a hairline crack in the potentiometer's own internal circuit board. The pot looks like one of the ALPS RK14 series.

[@hbmarcott]

2 years late, but the term you were looking for was wave soldering. The entire board with components installed and then floated (sort of) in a bath of solder.

[@johnharris1846]

really enjoyed this Jim! I have one of these on the way and pretty cool to see the innards of it.

[@tommybewick]

Obviously the heat effects it, but I don't think that points to a broken trace, could be the wiper in the potentiometer intermittently breaking contact when the case heats and expands and contracts. There is so much that heat could be doing that you cant see. Since TecSun still makes this radio I would just try to source the potentiometer from them and just replace it.

[@tommybewick]

Oops they don't make it anymore, I'd still try to get one.

[@kennynvake4hve584]

I use a string that goes behind the knob, or the matt that goes under your glass's or silverware in the cabinet. It has a grip to it.

[@edhusak]

I have one of these that went dead completely when I moved it to another shelf the other day. Thus, I get to go through the teardown scenario to figure out what popped inside it. I also need to deoxit the controls while it's apart. However... one thing I noticed in your video was the large opening behind the speaker. Why, oh WHY did they NOT simply put a power tranny and rectifier/filter cap board there instead of relying on a wall wart? Makes zero sense to me! And if these rigs don't have a clean LINEAR supply, they have an S8 noise level across ALL bands.

[@edhusak]

All those terminals on the pot is because it's stereo and not mono.

[@seravenerdi]

For such difficult knobs, it's because the mfg put glue. A simple trick is use a heat gun on low setting and warm it up.

[@johnbellas490]

I am fairly positive that you have all rotary encoders there, they are not easily repairable !! Try reflowing or resoldering all connections to this unit.

[@RuneTheFirst]

The term you were looking for was "Wave Soldering'.

[@davidgadd57]

I just started watching your video. I have the exact same radio and the same problem. Can't turn the volume down to zero. When I use headphones however on the FM stereo band I noticed the right channel works properly but the left is the problem.. I hope I can resolve this problem. I wondering if it's not the volume control and an electronic problem with the circuitry.

[@Darryl603]

Two spoons get under knobs and pry real nice without damage to the face plate...

[@seansoblixe9711]

I have a grundig 800 also. The AM sounded very distorted. After opening the back side and pulling on the three leads that go inside of the PLL metal enclosure and cleaning the lead pins the AM cleaned up, the distortion went away. Now i need to get the HF to pull in some ham stations. The pull up antenna does not do the job. Any suggestions? to my HF sensitivity issue?

[@imscuba]

I just bought a 800 with a similar sounding issue on LSB/USB and AM but only when AM Sync Detect is enabled. It sounds like WAY to much conversion gain, and makes USB/LSB/ SYNC AM 100% unintelligible. I may try this and see if this helps. What did you use to clean the pins? I have yet to pull mine apart. Regular AM is 100% fine, and so is sensitivity on all bands.

[@raghavaisaac5599]

Sir, I have Grundig Satellit 650 professional (bought used one in dead condition)..Display o. K.. While varying volume control pot viper sound is coming.. Means audio stage o. K.. But radio section not working... What could be the problem sir...? Kindly give me an advice...

[@SeanBZA]

Reason those knobs are sticking is that they were assembled while the plastic was fresh, and still outgassing the plasticiser. This then did 2 things, one was bond the plastic knob onto the shaft, and the other was shrink fit the knob as it evaporated away.

[@JimsRadioShop]

So it was not that I was weak. Thanks.

[@radio655]

Jim, the unconnected traces at the volume potentiometer might be vias. Issues like this one are ugly. Did you find a schematic?

[@JimsRadioShop]

By via, I'm guessing you mean there's a sleeve through the board to connect the traces on either side. I've studied the schematic. Scary.

[@mikehines4639]

Those holes are vias, copper plated through holes, used on PCB layouts that have trace routes on more than one layer. It is common for vias to suck up solder from wave soldering. This is a complex board in which wave soldering and reflow soldering (for the SMT parts) may have been used. Thermal profiles are usually run to determine the soldering requirements, producing high reliability connections. Determining all of this is the job of the manufacturing engineer.

[@RuneTheFirst]

"Why so many pins?" (on volume control): It was common some years ago to have stereo available through the headphone jack when on FM. That would explain why so many pins (3 per channel at the volume pot) and there could be more if there is loudness compensation. A look at the headphone jack will tell you if this is the case. The bracket of the volume control was probably being used as a jumper for the ground circuit. There is probably a break on top of the board that joins when it expands, The break is probably where the circuit trace meets the ring on the top of the board. You can access it by removing the nuts on the controls and pulling the board slightly forward.

[@SeanBZA]

7 pins say stereo pot with loudness tap at the point the 2 resistance ratios meet. common ground connection to the 2 tracks at the minimum position, then 2 concentric tracks, with a separate tap at around 1/3 for the loudness taps, then they go to the end at the max position for input connections, then there are 2 wipers. Common for any impact down these Preh pots to either snap the pin off at the board topside, or to snap the internal SRBP board of the pot, as it has the stress transmitted to it. Radio clock running off the residual voltage on the power supply capacitor is not surprising, the internal clock and LCD run off around 10uA when in standby, and if it was not driving the LCD it would probably be around 1uA, as it does not have to drive the display capacitance at 32Hz. Was restarting my radio yesterday, as it had locked up somehow ( SLA battery driving it died, dropped down to 1V during the night and locked up the 3V clock chip) and it took around a half hour for the clock to stop displaying, and another 5 hours later I put in the new battery and it fired right up. Not bad for an Aiwa I bought in 1987, though of course it is really only a radio now, as the tape decks have plastic issues and belt issues, and the CD player needs a new KSS150 laser assembly again. i use it now as a radio alarm clock in the mornings, though when the CD section still worked I modified it to add in auto play for the CD section, using a single CD4066B, to emulate pressing the play button 5 seconds after power on. Cascaded 2 RC delays using 3 sections of the IC, all on a tiny ( 7 holes by 16 holes) bit of Veroboard, tucked up on the back of the main logic board.

[@JimsRadioShop]

I'm suspicious that I simply did not get solder where it's needed.

[@RuneTheFirst]

@@JimsRadioShop You were working against gravity. Try putting the radio top-down/bottom up. Solder will then flow into things.

[@charleshall6033]

I am enjoying your video but I must admit I have gotten a little motion sickness.

[@rarbiart]

on this pcb there is so much manual rework (burned flux, manual resoldering) visible, that it looks like a refurbished (or at least reworked) board.

[@SeanBZA]

No, just that there was work done to manually add things that did not wave solder properly first time, and also things that would not survive the bath. Power IC with soldered heatsink tabs, because the top ground plane is so good at sucking heat from the kovar pin is typical, though those should also have had the standard copper plate fins placed in the holes as well so the IC can be run full volume without overheating. The IC manufacturers had a part number for that in the datasheets, and the "typical" specs included using that in the layout as well, or "equivalent part". Just that it added around half the cost of the IC to the price, and copper on the board is essentially free, though you need a really large ground plane both sides, with continuous pour, and not the hatching seen here, to be as effective.

[@kennynvake4hve584]

THERE IS SO MANY LEADS BECAUSE IT IS AN ENCODER 'NOT' A LINEAR POTENTIOMETER THAT HAS 3 LEGS.

[@widecast]

It could be a rotary encoder. The other controls look similar. It is strange that a jar on the control should cause such a fault. I wonder if that’s just a “red herring” and something else happened.

[@JimsRadioShop]

For now, I'm sticking with the 'hit the knob and broke something inside' theory. It was just a light tap with a lot of momentum behind it. The result was instantaneous so if something else happened, it has to be from the same accidental collision.

[@DAVIDGREGORYKERR]

That radio looks like it has DAB, That radio might use a rotary encoder to set the volume according to a certain value between 0-63 would equate from minimum volume to maximum volume ,as the whole radio is computer controlled just thinking, The volume control is not the type you are used to fixing.

[@rarbiart]

This chassis design screams from every corner _"i am a philips device of the 1990ies"_ so much plastic, so many crews, and all cables insanly short and/or nasty tight connectors.

[@SeanBZA]

Well, Grundig and Phillips shared a lot of stuff, not surprising as they often had the same manufacturing plant making them, and later on IIRC Grundig became part of Phillips, though the Phillips brand is still on consumer equipment, and Grundig is now Turkish owned.

[@ivanigorpollick6690]

you must be more gentle with radio

[@TheGalaxyhopper]

I WANT ONE!!! THE SOLDER GUN THING IS SENDING A RF OR HF DEAD EARTH TO GROUND TO GRUNDIG, JUST A THEORY THOUGH.52:10

[@TheGalaxyhopper]

I THINK YA BROKE 10 ONE INCH OAK PLANKS, WITH THE KNOB TENSION: @6:44

[@TheGalaxyhopper]

your solder test was THOROUGH, GEEZ, LOUISE, SHAKE RATTLE AND ROLL, BIG DADDY!

[@skykingimagery899]

Yes, designed to never be serviced. Typical European design. Like any fine Sports car.