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Could it be that stock faults in radios were relatively rare, Chris? The only one that springs to my mind is the contact cooled selenium HT rectifier used in a wide range of Bush radios but, on the other hand, I don't recall it being used by anybody else. 

I think there was so much similarity in the circuitry of all radios that, barring specific component faults like this, just about any fault could occur in any set from any manufacturer. TV design philosophy, on the other hand, varied considerably so that many faults were unique to specific sets.

Are you considering extending this to anything else - tape recorders, say? Take the Grundig TK20, for example. Open circuit w/w resistor in the feed to the record/playback relay. A common fault but unique to this model. Crackling on record caused by a leaky Wima cap allowing the capacitor microphone's polarising voltage through to the grid of the input stage. I'm sure that there was another common fault caused by one of these Wima caps but can't for the life remember what it was now!

Posted by: @terrykc

Could it be that stock faults in radios were relatively rare, Chris?

Hi Terry, I must admit I hadn't but did start to think it odd.

"Somewhere" I have a large amount of "Electrical and Radio Trading" extracts, these were full of "real-world" UK radio faults and included the solution to fix. Unfortunately  sods law dictates I cannot find them, no doubt I stored them in a safe place even from me. ? 

Posted by: @terrykc

Are you considering extending this to anything else - tape recorders, say? Take the Grundig TK20, for example

I don't see why not ?

What I may do, due to the lack of radio material, is turn the third category from "Radio" into a generic "Other" category which can be a catch-all.

Stock faults on UK 1950/60’s radios were pretty mediocre, capacitors, mainly paper or electrolytic, occasionally resistors or valves, dirty controls all very straightforward.

The transistors radios were in the main very reliable until the AF115 series came along, they were a stock fault themselves.

Mains operated transistor radios using the Ac128/AC176 range were another stock fault, usually with burned out emitter resistors.

These were in general very simple radios so were easy to fix, internal access to some was perhaps more of a problem.

After 50-60 years the same items will give problems plus others due to age.

A 1960 Ekco radio I fixed about 5 years ago, there is a thread on the site. I checked the resistors and changed a couple out of spec, replaced the 3 or 4 electrolytic caps and the half a dozen Hunts capacitors, turned it on and that was it fixed and still working.

Posted by: @nuvistor

Stock faults on UK 1950/60’s radios were pretty mediocre, capacitors, mainly paper or electrolytic, occasionally resistors or valves, dirty controls all very straightforward.

What you are describing are the everyday run-of-the-mill faults that could, and did, affect everything that you handled. To me, stock faults are repetitive faults that only affected individual models or ranges of models, the type of fault that you could go to right away - provided you were familiar with that particular set and its tricks - because you knew from the customer's description what was wrong before you even took the back off in many cases.

E.g.: 21Ω w/w resistors in the HT mains voltage setting of the Bush TV75, 85 and 95 series. Replace with the higher rated 5W RS type and always replace both! The CZ19 thermistor problem in the Bush TV125 series (reverse the positions of the new CZ19 and the adjacent 10Ω w/w to prevent a recurrence).

The unique faults I previously mentioned on the TK20. Only Grundig used a capacitor microphone - the input capacitor (if one even existed) on any other make of machine could have gone fully short circuit and nobody would have been any the wiser.

Hi Terry,

That was what I was trying to say, obviously not very well, it’s just I don’t recall those radios having the type of stock faults TV’s had.

Hi Frank,

What I was querying is that you stated - four times! -  that  everyday run-of-the-mill faults were 'stock faults' but they are not what I understand is meant by the expression. No doubt others will have there own ideas about it.

I doubt it is clearly defined anywhere. I tried a Google search and ended up with lots of railway rolling stock faults! Removing 'rolling' brought up a mix of farming and geological fault replies. I've seen lots of electrolytics erupt but that's not the same thing. At that point, I gave up!

Where we differ is that you seem to class any common fault as a stock fault whereas to me they are two different types entirely (although they are, of course, all faults.)

I like the google search returning farming, railways etc. Made me smile on the wet dismal morning.

Chris, just looked at /bush-tv105/ and found this reference to a resistor "coloured orange, orange, orange (331(52)"

Obviously 331 is a typo for 333 which I assume should be followed by (33k) but I can't see how this could end up as 52! 

Cheers Terry, the joys of spurious OCR errors. Now amended. 

Whilst sending a piece of kit I've sold on eBay, I've found several Bush "service notes" for various TV and radio receivers that detailed stock faults. They'll be scanned in due course.