Faulty Roberts R900 Radio [Repair Cafe] | Can I Fix It?

[@chrissavage5966]

Capacitors have been the root of so many issues over the years. A long time ago when I first started as an engineer with a certain broadcasting corporation in Britain, our studio had a bunch of Link 110 TV cameras and almost all the faults ended up being a shorted tantalum capacitor. The game was 'spot the tanty'. Usually pretty easy as they often had a small split on the case where they tended to eject a little splat of melted tantalum. The aroma as pretty distinctive too, so you could sometimes just follow your nose. The cameras had a very modular layout with plug-in boards and each had small inductors on the supply rails, these tended to act as fuses so it was invariably swap the dead tanty, replace the burnt inductors. Roll on a few years, another camera, this time Thomson 1530. The most common issue on these was a 0.1uF chip cap going short. The problem with these was Thomson used lots of things they called a 'PL' (it's french for something I can't recall), which were small hybrid circuit blocks on ceramic substrates and covered in a hard conformal coat, so we often had to play 'black box' and try to figure which cap was short from the outside. Then, of course, the whole 'fake' capacitor plague that hit lots of PCs. Lost count of how many motherboard re-caps I did to rescue some cranky old Dell or the like.

[@BuyitFixit]

Interesting. Thanks for sharing Chris 👍

[@technodaz]

I had one in the shop a few months back , old man loved his old roberts radio and while in the hospital a friend of his brought it to me for repair. Turned out to be the most simple thing ever , a little bit of plastic had broken off inside the socket that switched it from Battery to AC. It took me about 15 mins in total and even my boss jumped in with "no charge".....it was so nice to be able to fix something so old , inside was so nice to look at and so much hand wired and hand made , lovely break from the digital world.

[@BuyitFixit]

Nice story, thanks for sharing 👍🙂 and very nice of your boss too!

[@tonydarby9096]

I also volunteer in a repair club in Chingford NE London its very satisfying to help people keep their electronics going for virtually no cost. We only charge for parts that need ordering.

[@BuyitFixit]

Nice 👍yes pretty much same as ours although people can make a donation if they wish, to help with the rental costs of the building and tea coffee, and most importantly biscuits 😂👍

[@EuroScot2023]

Took me less than 1 minute to get the Roberts manual for the R900. Makes life so much easier, rather than probing around in the dark. Sophisticated radio with 3 ceramic filters and 3 ICs doing all the heavy lifting. Roberts have kept the same style for their tabletop portables for 50= years while the guts have moved with the times.

[@BuyitFixit]

Thanks for letting me know👍 About 95% of the devices I've looked at, there isn't a schematic or manual available so I probably forgot to have a search. I've since bought a job lot of 3 Roberts radios which are all different models, but I've yet to look at them.

[@steveosshenanigans]

Same over here in Australia, I volunteer at a local repair cafe its very rewarding to be able to fix items and keep them out of the land fill / tip

[@BuyitFixit]

Nice 👍We need more people like us 🙂

[@terrym1065]

Capacitors...need I say more? Gotta be the number one replaced component in audio repair. Great trouble shooting sir, always straight forward and easy to follow. Your patience is beyond reproach, a skill not many have. Thanks for the work and video, much appreciated, well done. Stay safe.

[@UnCoolDad]

And contact cleaner.

[@terrym1065]

@@UnCoolDad Yep!

[@BuyitFixit]

Thank you 👍

[@AppliedCryogenics]

I'd never heard of a "repair café" before. It sounds like a magical place!

[@BuyitFixit]

It's a world wide thing. It's where people can bring their broken items and volunteers such as myself try to repair them. www.repaircafe.org/en/visit/

[@bellytripper-nh8ox]

@@BuyitFixit IN A FUTURE VIDEO YOU SAY **I FINALLY FIXED THIS RADIO. IT IS WORKING GREAT ON ALL BANDS!! TOOK ME A WHILE, BUT MY DILIGENCE PAID OFF!!**

[@Dime_Bar]

I bet them capacitors were dryer than a nuns, you know what lol. I'm amazed you were able to find a circuit diagram for something that old.

[@BuyitFixit]

😂😂😂😂👍

[@generaldisarray]

It's always the caps, or the diodes... OK it's always 85% the caps, or maybe the diodes, oh wait, it could be the IC... Alright, it's always 65% the caps, or the diodes, or the IC... Bugger, it could be the transistor... Fine, it's always 35% the caps, or the diodes, or the IC, or the transistor... OK, look, we can say with some level of certainty, a level "UP TO" 100% that it's ALWAYS the caps...🤣🤣🤣 Ah the good old, reliable Roberts radio, the radio of choice to sit by in the 80's and await instructions if the Russians ever dropped the big one... Think Threads, or The Fourth Protocol. Outstanding detective work and repair, as always, Mick.

[@micronetwork]

🤣😆😁

[@BuyitFixit]

Cheers mate 😂😂👍

[@chrisbartlett6022]

I have a similar radio, used to be my Grans, have not been brave enough to turn it on for ages, need a neighbour like you 🙂

[@BuyitFixit]

@@chrisbartlett6022 😂😂😂😂I won a lot of 3 of similar radios fro Ebay. All slightly different models. I've yet to look at them.

[@MikeB_UK]

Great fix. Good to see an old British radio given another lease of life. It's always much more fun when we get to see the 'scope in use. Love watching your diagnostic process. Keep up the great videos.

[@BuyitFixit]

Cheers Mike 👍

[@raygianelli3612]

Nice job as always, Mick! Been my experience that 6.3 and 10 volt electrolytics are far more failure prone than their higher voltage cousins.

[@BuyitFixit]

@@raygianelli3612 Thanks Ray, and cheers for the info 👍

[@gsp911]

I love the idea of ​​a repair cafe, it's so cool. 😁 I wish we had something like this where I live. I'd sign up right away. Loves fixing old things.

[@gsp911]

Btw, I think it's a PP9 connector.

[@BuyitFixit]

There might be one near you already 🙂www.repaircafe.org/en/visit/ 👍

[@gsp911]

@@BuyitFixit Not a single one in Denmark. 🙁

[@BuyitFixit]

It could be an opportunity for you to start the first one in Denmark...🙂

[@gsp911]

@@BuyitFixit I've already thought about it. 😁 That could be fun.

[@Gazzyb2071]

It's amazing how you diagnosed the fault, especially for me as a newbie to electronics. Very interesting, well done, mate. 👍

[@BuyitFixit]

Thank you 👍🙂

[@Malmes999]

1985 thats the day we went Back To The Future! 1.21 jig A watts! good repair as always👍

[@BuyitFixit]

😂😂😂😂Thanks 👍🙂

[@steventalmakkies6015]

This reminded me of the radio my grandmother used to have, she loved that radio.

[@BuyitFixit]

Nice 👍

[@greg6172]

Yes electrolytics and other caps can be a real problem. Back in the days of Astor and Classic valve based TVs a complete cap change was usually the fix. Thanks for the thorough diagnostic approach and I look forward to the next one. All the best from Oz.

[@BuyitFixit]

Thanks and best wishes from the UK 🙃

[@joseph_donovan]

Sweet repair. Made my ear lobes tingle with delight. Thank you for making and sharing. Best wishes.

[@BuyitFixit]

Thanks Joseph 👍

[@allenrusselljr]

Your videos are always clean, positive and i actually learn something. Thank you

[@BuyitFixit]

Thanks 👍

[@barendnortje9382]

Love the video, please do some more audio repairs. Thanks for always being so polite

[@BuyitFixit]

Thanks 👍I've bought a sony XPLOD car amp which is faulty so that will be a future video...

[@shawnphenry]

I enjoy watching the repair process and troubleshooting steps. I retrieve failed POE injectors from my work and am currently trying to diagnose and repair them for fun. Thanks for showing us how you do it!

[@BuyitFixit]

Thanks and good luck with the POEs!

[@ThriftyToolShed]

Those electrolytics... they will sit and get dry and bite us for sure. Excellent repair. I am jealous of the 2 ft thick stone walls. I bet the house is much cooler in the hot weather. I live in the southerm US, and it's been nearly 100⁰F much of the last month 🥵 🫠😅

[@BuyitFixit]

Thanks 👍Yes cooler in the hot weather, but also freezing in the winter!

[@joelkist6493]

I Like the way you trouble shoot; very nice work!🙂

[@BuyitFixit]

Thank you 👍

[@phildxyz]

Had a Roberts years ago - lovely bit of kit.

[@BuyitFixit]

Yes I'm pretty impressed with the sound quality 👍

[@HE-pu3nt]

Roberts use to make some serious HiFi equipment. You could have easily spent £10,000 on a system before you bought a turntable, speakers and leads. But that was 25 years ago. I use to work there in Heckmondwike. It's just a shell company now, selling Chinese crap.

[@BuyitFixit]

Interesting. Thanks for sharing 👍

[@uhd25ca85]

Another brilliant video, this channel is awesome. Thank you for making the content!

[@BuyitFixit]

And thank you too for letting me know 👍

[@smbrob]

Smart to repair this one..... the way your country is going, you might need a battery radio soon.

[@BuyitFixit]

Yeah 👍Luckily I live pretty far away from any cities, and we're pretty self sufficient with water / power etc.

[@lmwlmw4468]

Resembles a lot like an old ´´Grundig´´. Yeahp, these old electrolytic caps always fail to stay in good health ....!!! Great video.

[@BuyitFixit]

Thanks 👍

[@ibrahimkocaalioglu]

Well done as usual. I watched all your videos in one week. 👏👍

[@BuyitFixit]

Awesome, thank you!👍

[@neiltheplayer]

Thanks for posting once again. Cheers! I was playing catch-up today, was out of town for just over a week

[@BuyitFixit]

Cheers Neil 👍

[@darrenwardell3079]

“I’m raving” Great vid on how caps seem to be the number one culprit 👍

[@BuyitFixit]

Thanks Darren 👍

[@sean9595]

You make it look so easy,Mick 👍🏼👍🏼

[@BuyitFixit]

Cheers Sean 👍

[@lawrencemonaghan926]

I've got an R606-MB, nice sound 😊

[@BuyitFixit]

Nice 👍 The sound on this one was pretty good too.

[@brianwood5220]

Great video, Mick. Love the diagnostics and your patients. Thanks for sharing.

[@BuyitFixit]

Cheers Brian 👍

[@leonardgucciardo8386]

I wish they had repair cafes in the USA. Sounds like a great idea and I would love to volunteer.

[@BuyitFixit]

They do indeed have them in the USA! although the US is quite a bit bigger than the UK. There is an interactive map of locations here: www.repaircafe.org/en/visit/

[@leonardgucciardo8386]

Thank you so much for the info. You are and inspiration to us all.

[@TheElectronicDilettante]

Great repair as always. In my ongoing journey to learn electronics, I’ve recently delved into curve tracers. I started with a cheap, subpar version from Amazon, which only fueled my desire to seek out a more reliable tool. I ended up building a couple of basic curve tracer circuits from old electronics texts, which actually worked better than expected. Through this experience, I realized how valuable curve tracers can be. They allow you to quickly test components in-circuit, often eliminating potential faults just by observing the visual representation on the display. Additionally, they can detect faults at higher frequencies or under conditions that a DVOM might miss. Finally, allows for the timely testing of RF circuitry that can contain transistor, inductors, capacitors in bulk. All the while, we get to see the oscilloscope in use. You should check one out, or build one. I bet it would help streamline your process. Thanks, as always, for the video.

[@BuyitFixit]

Thanks 👍I might look into that, although the problem with using things like scopes and thermal cameras is that not everyone has them or knows how to use them. The spirit of the channel when I created it was to help people repair their own items, or help them diagnose problems. I normally resort to my trusty meter most of the time 😂

[@Zodliness]

I found capacitors and variable pots are the two most serviced/replaced components second only to batteries. 😉👍

[@craftsman123456]

Across the pond here I've never seen that radio I really like the style of it

[@BuyitFixit]

Yes made in England, it has pretty good sound too!

[@JustInspiredKent]

Thanks for sharing! I really enjoy your videos. With all the brilliant tech repair KZbinrs about, I've learned quite a lot and now able to fix even more stuff for my customers. ♥

[@BuyitFixit]

Nice, Thank you 👍🙂

[@millzee60]

I had a Grundig of the same era and style. Beautiful sound and covered in kitchen grime too:)

[@BuyitFixit]

😂😂😂👍

[@richardtaylor7199]

Hey not bad for a Sand Dancer, great vid.

[@BuyitFixit]

😂😂😂😂

[@wicklowmountains8618]

Thank you for sharing your great talent, You have giving me the bug now.

[@BuyitFixit]

Nice 👍Good luck on your repairs! I've repaired quite a lot of items on here so hopefully you'll like some of my other videos too!

[@wicklowmountains8618]

@@BuyitFixit I have seen a lot of your videos from the last year and you do a great job explaining how to find and fix problems. Cheers.

[@ralphj4012]

Good to see a classic brought back to life. Odd to see shorted electrolytics, a leakage current test would have been interesting.

[@BuyitFixit]

Thanks Ralph, yes I thought it was odd to see a shorted electrolytic I can't recall coming across that before.

[@johnwatson8820]

As always a great and interesting fix ,great watching you ,best wishes take care!!

[@BuyitFixit]

Thanks, you too 👍

[@mikecass8306]

Well done again, thanks Mick 😀

[@BuyitFixit]

Cheers Mike 👍

[@EsssTeeeBeee]

Great video, love the random repairs. I routinely change all caps when servicing a radio of this vintage, I know this is controversial though!

[@BuyitFixit]

Thanks 👍Yes I do try to mix it up a bit. Just repairing one type of thing like console, console, console for instance gets a bit boring. I also like doing weird items that no one else has looked at or tried to repair before. Sometimes it just depends on what comes my way 😂😂😂

[@jumboegg5845]

Satisfying to watch you think. Sometimes can be useful to switch the multimeter to ac voltage, gives you an idea if there is any ripple on a dc rail. When you got those low dc voltage measurements, (for example the power rail to the big am/fm chip) would have interesting to see how much ac voltage was on it.

[@BuyitFixit]

Thanks, and good idea on the AC. I hadn't thought of that!

[@jumboegg5845]

@@BuyitFixitYeah its easier than getting the scope on to it. Just sharing knowledge that I picked up from other people, it makes the world go round! I've learnt heaps from you.

[@stevedebeukelaer1424]

Nice work

[@BuyitFixit]

Thanks 👍

[@mrjsv4935]

Nice fault finding and repairs. Classic looking radio, looks to me at bit more like 60's - 70 s product than typical 80's radio, or boombox :)

[@paultasker7788]

Think they made them into the 80s. My dad had one. Sound quality was surprisingly decent.

[@BuyitFixit]

Thanks Mr Jsv 👍

[@jasejj]

@@mrjsv4935 Just typical British product of the time. Technologically backward and quite expensive for what it was, but well-made and usually decent-performing. It's why most of them went bust, unfortunately.

[@alfredocuomo1546]

I have a bunch of old CB's and that's the first thing they all need is every electrolytic Capacitor replaced before even look to fire them up. Best part is you can smell them they're so bad. lol

[@BuyitFixit]

Hmmm.. smells a bit fishy to me 😂😂👍

[@ianhuxstep211]

There are service manuals available on the internet for all Roberts radios. I have them. Roberts radios usually use the positive as chassis not negative as you would think. If you ever get a really old Radio with AF series transistors these usually suffer from tin whiskers, there are methods to clear it.

[@BuyitFixit]

Interesting. Thank you for sharing 👍

[@andygardiner6526]

Years ago (in the late 80's) we used get boxes of non-working Roberts radios from the local Institute for the Blind and fix them up for free. Very few major faults - most often it was a battery replacement (they ran them on batteries for ease of use) or switches/pots needed sorting out.

[@BuyitFixit]

Nice story, thanks for sharing 👍🙂

[@fredwooding599]

A perfect example of how age can kill caps. Nice job Mick.

[@patrickcallahan2210]

A possible option for testing radios in the future when you don't have signal might be one of those bluetooth FM transmitters for cars that don't have bluetooth or USB. They do a low power FM transmission which is bluetooth tethered to a phone/device.

[@BuyitFixit]

Thanks 👍Yes, I had thought about that. I've got a USB FM transmitter that I used to use for my Xmas light show I built a few years back, although it would only be good for testing the one band.

[@mainecoonman]

If you can't access the bottom of the capacitor you can cut the wires and solder the replacement cap to the cut wires on the top of the board.

[@BuyitFixit]

True, good idea 👍

[@Bloke-in-Stoke]

Well done and I don't blame you one little bit for avoiding the tuning cord rigmarole... they were the bane of my early career. You do that little bugger will fail next week don't you? 🤣👍Cheers 🍺

[@BuyitFixit]

Thanks 👍😂😂😂😂

[@jasejj]

I refused to believe that an electrolytic could go short, until I found one on a Toshiba cassette deck a few years back. So I was screaming "cap" at the TV here! 😂

[@BuyitFixit]

Yes, I've can't remember having one go dead short like that before. They just usually go open circuit and have no capacitance 👍

[@Ragnar8504]

@@BuyitFixit Some are known for shorting, like golden/yellow/orange Frako ones. I think these grey ones have a pretty bad track record too.

[@wisher21uk]

Brilliant repair Mick, I was wondering if you were going to change all the caps, I learnt the hard way too I did a tv repair and on the power supply there were 2 capacitors in parallel and I only changed the bloated one, yes! You guessed it a week later it came back and the original one of the two was bloated and caused the same fault!

[@BuyitFixit]

Cheers Gary. If they are linked in parallel then I would have changed both, but I've done quite a few TVs where there has only been something like the bootstrap cap has failed and replacing it brought it back to life and it was still working years later. I think it depends on how much abuse the caps are taking in the circuit.

[@wisher21uk]

@@BuyitFixit true and the quality of capacitors count, you can get say Ashchem ones cheap and might last a year or Panasonic ones that last for years and years. And using a higher voltage rating is always a good move

[@gerardcarson2779]

Neat diagnostics and a good fix. For future reference Radiomusuem and the Roberts Radio Group are good (and free!) sources of schematics and technical information on these types of radios. The R900 is a nice radio and always worth saving. :-) Gerry

[@BuyitFixit]

Thanks Gerry 👍The schematic I found came from radio museum 🙂

[@luckywetland]

Great fix, Mick :)

[@BuyitFixit]

Cheers Mate 👍

[@TC_here]

If its old tech its going to be the caps. Nice repair.

[@BuyitFixit]

Thank you 👍🙂

[@599miata]

Great job, mate. I always do a complete recap on such a job. You guarantee yourself for no comebacks. Good work. I like your moves, mate😂😂

[@BuyitFixit]

😂😂😂Thanks mate 👍🙂

[@Georgeolddrones]

You can’t get a signal on the radio because of where you are, but we can get one from Mars 😂

[@BuyitFixit]

😂😂😂I don't think the walls are 2ft thick stone on Mars though 🙂👍

[@elsaarmstrong-zp6ng]

You need a good outside aerial if fm poor reception because thick walls! Esr meter best for caps! I have found some eletrolites read capacitances ok but esr still high! Some show low capacity which means parallel internal resistance I think! I got esr meter off Amazon for £40 . Well worth it as it injects 100Khz and measures impedance which shows up as esr! Also measures impedance of coils and shows up shorted coils in transformers! Fraser! p.s. video of this Roberts very good and they are sought after radios!

[@BuyitFixit]

Thanks for that 👍The little component tester I've got shows the ESR although I'm not sure how good it is.

[@RobbiePohlmann]

Mick, may want to test electrolytics for ESR in future repair projects. Nice repair.

[@BuyitFixit]

Thanks, the little tester I tested the main smoother cap shows the ESR.

[@richb419]

Hi, when I work on something that old, I found it's always a good idea to change the electrolytics out.

[@chrisprobert6]

Good practice, but what a ballache😅

[@BuyitFixit]

Yes, bit of a ballache 👍😂😂😂

[@Lightrunner.]

18:08🤣🤣🤣🤣🤣 that happened to me too. The best mistakes are the ones you make yourself👍👍 Usually after 25 years there is a capacitor massacre. 99 percent can be exchanged You are working in a Repair Cafe ??? Me too 🤗🤗🤗 Amazing 👌🖖🖖🖖

[@BuyitFixit]

Cheers mate, yes our repair cafe is only on once a month. I've got a few other items still to look at but sometimes easier to bring items home to work on, as some items I have to order parts or require microscope etc to work on. If it's a simple repair and we have parts we just normally do it there and then.

[@xzytqweo3538]

Doesn't surprise me the "caps" went bad or were going bad. My Mate Vince worked on several Roberts components and his were "cap" related problems as well.Great job trouble shooting.

[@BuyitFixit]

Thanks 👍

[@zx85]

19:09 "I think the mains lead's pulled out" .. *sticks fingers into the case of the radio* Had me panicking there for a minute..!

[@BuyitFixit]

😂😂😂yes I meant the low voltage lead from the mains transformer. Sometimes it's hard keep talking and sharing your thoughts while recording, and troubleshooting at the same time 🙂

[@zx85]

@@BuyitFixit 😁😁 you do a brilliant job!

[@digihorse6730]

Nice job but i was cringing at the end as you were moving the solder sucker with the AC in end of the pcb. One point don’t try and tune AM LW with the radio resting on the turned on multimeter, the noise from the multimeter will kill the reception. Love your videos keep up the good work.

[@BuyitFixit]

Thanks, luckily no shorted out solder sucker 😂😂

[@DifficultyEasy]

At 22:16 it looks like you shorted the positive battery input to ground IF it's not diode protected. Wonder if that blew the second cap?

[@BuyitFixit]

No, there's a diode there (first diode that I checked on the video when looking for shorts). It was playing happily for about 30 mins before the second cap failed (which gets its power via a 1K resistor and feeds the audio amplifier).

[@StewartAlsop-g5l]

Where is the repair cafe you volunteer at?

[@BuyitFixit]

It's at a place called Alston in the Northwest Cumbria.

[@LovelyFish-wg1dq]

Always good sounding radios the Roberts. What would recapping a similar model normally cost? Thanks

[@BuyitFixit]

I would have thought the capacitors would cost somewhere in the region of £10?

[@esbenarndt5703]

Nice radio

[@KericthePally]

Actually have this exact radio but it's got red "leather" instead of black. I have a few different Roberts radios that I bought when I wanted an old radio to modify. It's weird knowing what the solder points you're probing are connected to. I had to do the same investigation to work out how the buttons and sound could be used for modding.

[@BuyitFixit]

Interesting. Out of interest what modification where you doing?

[@eugenijusjanuskevicius2292]

Try to revive the cap. They age without a voltage applied and loose their oxide layer, which is coincidentally the isolator between the poles.

[@Ragnar8504]

This radio must have been quite a retro design back in the mid-80s, the outside looks more like mid-60s to me! Did you have a look at C53? It seems to be a different brand but it might fail as well. The size difference between the footprint on the silkscreen and the actual cap is crazy 😂

[@BuyitFixit]

I did notice that cap seemed to be a different brand and the footprint seemed to be a lot larger on the silk screen. I didn't change that one, wasn't sure if it was a factory modification or a prior repair.

[@Ragnar8504]

@@BuyitFixit It looks to be the right age to be original, I've seen some 80s equipment with the same mix of grey and lilac-coloured electrolytics. Could still be a later replacement though.

[@BuyitFixit]

@@Ragnar8504 Someone mentioned it's a mod that they did to stop the power switch burning out which started happening on earlier models.

[@user-dj3nq8ty1o]

This is a little off topic, but how many and what kinds of anti repair things have you run into

[@BuyitFixit]

Good question, well FLIR were not very helpful when I wanted to order a part (video on here fixing a thermal camera) and a solar inverter company weren't very helpful when I repaired a solar inverter and needed a password to adjust a setting (so I had to resort to reverse engineering their software and writing my own password tool) video is also on here (no password no problem). The starlink router wasn't a very repairable item.

[@Harfinou]

First rule : when trying to fix old old old gizmos, check the caps first. 😃

[@BuyitFixit]

Great tip 👍

[@paultasker7788]

Pretty much guaranteed to have faulty caps if it's this old. They may have already been replaced once before?

[@BuyitFixit]

I'm not sure if any had been replaced before. There was one small cap in a large footprint so but not sure if that was a factory modification or not.

[@Dutch_off_grid_homesteading]

Heya, after some time does caps wil go bad. have a simiilar kind of radio standing here were the batteries leak on the pcb I'm afraid to open it lol

[@BuyitFixit]

Yes, the electrolyte in the capacitors dries out over time, I'd not be afraid to open your radio as it's only going to get worse the longer you leave it...

[@idontneedaname85]

@mrcarlsonslab would be proud!

[@BuyitFixit]

😂😂👍

[@Alberto_Alletto]

I like radio repair 😃

[@BuyitFixit]

I've got a Sony XPLOD car amplifier which I bought from eBay to look at for a future video 👍

[@Alberto_Alletto]

@@BuyitFixit 💪

[@elsaarmstrong-zp6ng]

Is the mains cable coming in at 240 V or is it off a adaptor 9 - 12 volt ? I have worked on Roberts long time ago! You have to watch some of these old radios with 2 pin 240 V raw mains and caps at DC! I have had a few belts during my 50+ years in electronics but still here with my 80th birthday coming up this year!😂Fraser

[@elsaarmstrong-zp6ng]

You have to be careful switching on old valve gear that hasn’t been on for years! I had an old vox amplifier like the Beatles used to use - stupidly switched it on straight off the mains - silence then burning smell. - BANG! Like a grenade ! I almost s..t myself! Big Capacitor exploded electrolyte the all over the chassis! Got a 60 watt filament bulb and amp meter now in serious with whatever I am going to work on! Yes you live and learn! Fraser😂

[@BuyitFixit]

Yes I had something like that with a Starlink router so I've since built a dim bulb tester too 😂😂👍

[@BuyitFixit]

Yes, had a few belts myself over the years, most recent was a motor startup cap that failed on our boiler. I used another to verify it was the cap, and just connected it briefly until the motor span up. Picked it up a bit later and forgot it was charged..

[@elsaarmstrong-zp6ng]

@@BuyitFixit Yes you have to watch these capacitors! I remember crt’s as well still charges left on them after being off several weeks! I always strap the anode to ground before I touch anything like that nowadays!

[@GapRecordingsNamibia]

The only reason for a cap going short would be the slow boiling off of the electrolyte and then charing of the insulator, the only thing that causes that as far as I know is a slightly higher voltage but one that is not high enough to cause physical failer, it might be a good idea to check the transformers output, in the 80's the grid voltage was closer to 215 or 220VAC now - a - days it is closer to 245VAC. I think the slow increase in grid voltage a has caused those caps to fail, it might be wise to replace those caps with higher voltage rated caps, eg. 16V ones for just in case it is a higher voltage that is causing it...

[@BuyitFixit]

Good idea with the mains voltage 👍I actually replaced all of the caps with higher voltage rated anyway as most of the caps I had were either 16V or 25V 🙂

[@audibell]

Good

[@BuyitFixit]

Cheers 👍

[@eliotmansfield]

wasn’t lying when he said walls are two feet thick 😂

[@BuyitFixit]

Yep, you can see them on the windowsill the radio is on 👍😂

[@twotone3070]

I've only done a couple of sessions at our repair cafe and it's been mechanical repairs so far, so I haven't had the pleasure of an electronics fix. Having said that I wouldn't want to be bringing things home and we don't have spares on site, so I'm not sure what will happen.

[@BuyitFixit]

Good on you mate 👍There are a couple of us do electronics at our cafe. Some do things like toasters / lamps / lawnmowers, and I usually get the more harder stuff. I sometimes offer to take stuff home because if it's an interesting item, it saves me having to buy a broken item to make a video, so it's a kind of win-win for me 🙂

[@RichardV318]

The battery connector is for a PP9 9V battery (no longer made).

[@BuyitFixit]

Yes, I put it up on the video as was curious. I did find them on Amazon www.amazon.co.uk/Eveready-Silver-Battery-GP1603S-MN1603/dp/B000LMQ3SK

[@lt200420]

Holy shit :) could someone tell me the name of that Bittersweet Symphony remix we hear for a moment at near the end of video? Also nice repair.

[@ThermalRunaway]

kzbin.info/www/bejne/mWa3eJWtiZZle6ssi=ax7BPJZOSfvU2ifk - maybe? Not 100% sure though.

[@BuyitFixit]

Thanks 👍Not sure about the remix, it was BBC Radio1 as that's pretty much the only FM radio station I can receive around here 😂😂

[@pjmelect]

When you discovered the first Capacitor was short I thought that you did a lot of unnecessary tests I sussed that it was the cap that was short straight away and I was surprised that you did not. Did you do the unnecessary tests to try and make the video more intresting?

[@BuyitFixit]

I'm not too sure what you mean. I've never came across an electolytic that has shorted like that before, only surface mount capacitors.

[@pjmelect]

@@BuyitFixit It is not that uncommon to find that an electrolytic capacitor has gone short, as electrolytic capacitors often go very leaky. When is a capacitor very leaky or a short? That is open to debate and depends on the circuit it is in. I find that old computer power supplies produce the most “short” capacitors, however if you were to measure them they are often a few ohms. In the video I thought that you did unnecessary test and that you should have found the problem almost straight away.

[@EssGeeSee]

Parents had a Roberts valve radio.

[@BuyitFixit]

Nice 👍No doubt one will end up on my bench at some point 😂😂

[@dominicwebb8000]

The electrolytic’s always breakdown with age. If you cut them open you will see they are thin metal sheet separated by a greasy type of paper. I think they dry out over time. How do I know, well as a kid I used to reverse polarity these, they then explode with a decent bang, it also blows out the inside, easy to work out their construction when it’s littered over your bedroom carpet.

[@BuyitFixit]

Yes, the electrolyte dries out over time. I too used to do that with old PCB's etc when I was a kid too! Tantalum bead caps were quite energetic too, you ended up with a red hot piece exploding off that usually resulted in a small burn on the carpet where it landed 😂😂😂😂

[@dominicwebb8000]

I seem to remember they made a real stink when they popped too. Glad to see someone else had a misspent childhood too.

[@BuyitFixit]

😂😂😂😂👍

[@modernelectricelectronics4896]

Hi There C 53 supposed to be a big cap not sure a TINY soldered , i.e, should be 1000uf 25V

[@BuyitFixit]

Yes I noticed that there was a small cap in a big footprint. I thought it must be a mod from the factory as I don't think anyone else has looked at it as far as I know. I didn't change that one actually.

[@paulwomack5866]

@@BuyitFixit Check out the power switch mod in the official service manual

[@BuyitFixit]

Thanks, yes I guess they reduced the size of the cap for the current inrush.

[@Andreas_Straub]

Replacing the electrolytic caps should always be the first thing to do with such old devices ....

[@elsaarmstrong-zp6ng]

I think capacitor troubles are due to heat! Look at guitar amplifiers like Fenders ! They are mounted upside down with hot valves pouring out high temperatures which heats the chassis up to rediculous levels! Uncle doug replaces most of the caps before he switches on to check the amp!😂

[@BuyitFixit]

Heat and high frequencies. Heat in old devices but switch mode PSUs usually fail a lot quicker due to the high frequencies being used.

[@elsaarmstrong-zp6ng]

@@BuyitFixit I have noticed that as well. I don’t think capacitors like high frequence spikes especially electrolite types! I have a old psu out of a telephone exchange and capacitors like beer cans ! Heavy loaded there is no ripple on the 48 volt dc output ! It must be about 70 years old! Transformer very heavyweight! 😂

[@tarzanjungle-king8634]

Can you rewire/shorten/join a headphone lead, razor headset? Dog chewed the lead.

[@BuyitFixit]

If it's not something you can do yourself, you could try one of the repair cafes like the one I volunteer at. It would be a fairly straight forward repair. I'm not sure where you are located but there may be one near you. www.repaircafe.org/en/visit/

[@tarzanjungle-king8634]

@@BuyitFixit in Ireland, unfortunately there are no repair cafes like that near that I'm aware of. I did look at myself and tried to join but there are 5-7 fibre type wires. Probably not possible, just said I'd enquire after watching your tractor and baler repair videos. Thanks for replying. Keep up the grrat videos.

[@LawpickingLocksmith]

It must be the Fluke?

[@BuyitFixit]

😂😂

[@RobSwan-y5y]

For my understanding. - you measure 9.7 ohms across a cap and "its short". Daft question but what would you expect?

[@BuyitFixit]

I'd expect the resistance to fall and then slowly rise as the capacitor charged from the meter.

[@esbenarndt5703]

A signal tracer would be nice here