Is this the end of my radio tuner?

Fogmatic

I have a Sony compact hi-fi system (XO-D501CD), vintage 1980s I think but still sounding fine. The radio gets the main BBC stations (in Donegal, with just an indoor antenna).

It did until yesterday that is, when the radio sound (together with its illuminated display) abruptly went off about a minute after turning it on. It lasts about a minute every time I turn it on, if it's been off for long enough. It's as if something warming up breaks a connection - if I turn it on & off in quick succession, it works for fewer & fewer seconds, then won't come on at all (unless a few minutes have elapsed).
I can hear CD & tape OK.

Does anyone know why this is, and/or if it's fixable?
I don't know much about electronics, but would rather go the d-i-y route. I don't know any electronics buffs in this country, and the only way to have stuff checked round here is to lug it to a shop, which has to send it away for weeks even to get an initial opinion.
I haven't had to open up this particular hi-fi yet, but opening it looks simple and I'm quite happy having a go at this sort of thing (no guarantee worries with this one!). I've often looked inside failed radios etc and found an obvious broken wire, for instance.
The radio, tape decks & amplifier are in one box around 1ft cube (no record player on top; they were separate units, like the CD player).
If there's a fix, and any component is needed, I'd probably start by trying Maplins (their mail order's probably quicker than reaching other shops from here).

If the tuner's dead, it's shopping-around time (I'd miss my Jazz Record Requests etc!).

crosstownk

I'm no expert but it sounds like a possible problem with power supply to the tuner/display. You'll need a set a of schematics and a multimeter to do basic checks. You'll also need a lot of Googling and some knowledge of electronics.

Fogmatic

Thanks crosstownk.
I always wanted to know a bit about electronics, and did buy Electronics For Dummies about 2 years ago. I've only skimmed through it so far, but gathered a few specialist tools would be needed to go beyond finding obvious mechanical faults. I'm undecided; buying the tools wouldn't be a problem, it depends on how much time would need investing to master the basics.
I tried Googling (just briefly) for a schematic, but it seemed a bit of a closed shop.
I haven't looked inside the hi-fi yet, but there just might be one there (some 1980s radios etc I had came with circuit diagrams).
I was going to open up the unit today for the first time, just in case there was anything visibly loose. However, before disconnecting it I tried the radio again (for the first time since the last posting), and it worked for 2 hours, until I had to turn it off to go somewhere else. Mysterious!
There's a fair bit of humidity in our house, and the associated CD player needs drying out sometimes before it'll work (by leaving it on for a while). I wondered about humidity re the radio fault, but that seems rather counter-intuitive. Perhaps there could be some connection though? (no pun intended!)