I've just this past weekend been to collect a dog-eared example of this set - to put it this way, the pots on the back have fallen off and there seems to be some kind of muck that falls out the bottom with every movement of the set.
Just two questions I can think of before I finish off my Philips 485U (sorry that's stalled, guys, what with Christmas and redecorating and everything):
How do you:
1) Switch the set on? I can't tell whether this stiff switch is a spring-loaded button or a dial.
2) Tune in the presets? Only the 2 and 4 presets will turn (stiffly), so I presume they tune one channel when pressed in and another when out?
OK, so I couldn't resist getting the back off.
This is the rustiest set I've seen for its' age! Could someone verify if the LOPT is a write off? It looks like it will need some work on it as it's caked in rust!
Will post pics in a bit.
Rust sounds like the problem. All 4 tuner knobs should rotate. the on/off switch is ganged with the volume control.
Al
I fixed one of those back in the mid 1980s.
It had a "zit" on the LOPT not far from the EHT cable. The owner agreed to pay up for the part.
The supplier told me that they always go and explained the failure mechanism.
The duff ones were white and the good ones pink so you will need to clean it up to find out if it is a good one. The odd white one did last though.
Pics.
Some back assembly pots have rusted off.
The UHF socket has rusted solid to the aerial cable inserted into it. To get the back off, I had to cut the aerial cable (wincing at the thought of this!) The white block to hold the aerial input in place is present, it's just off-photo.
The LOPT looks like it might have had it!
I don't want to put you off,but it all looks rather rough.. hopefully though after a clean it may look a bit better.
Cheers
Neil.
That looks like a very early LOPT but it is resin potted and may well still be all right.
It looks like it has been in a building that has stood empty for a long time and may well clean up nicely.
I don't want to put you off,but it all looks rather rough.. hopefully though after a clean it may look a bit better.
Cheers
Neil.
You're joking aren't you? Rough is an understatement 
As it is topical it looks like its been caught in a flooded property. I have seen items flood damaged and it looks similair.
Chris
To answer your first 2 questions:
1. The on-off switch is a spring-loaded push button. Press it in to switch on. Press in again to switch off - the button should spring back out. Occasionally I've encountered a broken switch where the button won't stay pressed in.
2. To tune in a channel, press the button you wish to tune e.g. BBC1. Turn the button clockwise to tune to a lower UHF channel (towards ch. 21) ; turn anticlockwise to tune to a higher UHF channel (towards ch. 69). When the knob stops turning, you've reached the end of the tuning range (lowest or highest channel).
It looks a bit of a mess, but don't be too disheartened. I would simply take it outside and brush off the dirt with a paint brush (available from your local pound shop). Take a look at the chassis after cleaning the dirt off. Don't worry about surface corrosion. Just look out for any PCB tracks or components which have corroded away completely. You can check these with a multimeter. If it doesn't look too bad after cleaning, there's nothing to lose by powering it on briefly and seeing what happens. The broken preset pots are cheap to replace, so don't worry too much about them either.
With a set in that state, would it be a good idea to try it out on a bench PSU (assuming it has a 12V socket on the back)? That way you could wind it up slowly, or even limit the current so you hopefully won't blow anything up.
Lloyd.
Well, made a bit of progress on this today. Am searching my stock of caps for replacements, and ordering any not in stock.
Some of the capacitor legs have completely or partially rusted. All suspect-looking and evidently long-gone caps have been ripped out, including all of the ones from the line output stage, all of which were manky!
Core what a load of rusty capacitors.
I bet they would still work if you could make a reliable connection to the tiny rusted stubs of the leads.
There would be little hope of doing anything else but replace the poor old things.
Was this set dredged out the bottom of a river?!
Was this set dredged out the bottom of a river?!
That's what I've been wondering
Added to all this, one of the clips in the anode cap has rusted off, too. The others seem fine.
I hope the IF coils haven't suffered too much...
I hope the IF coils haven't suffered too much...
Blimey, that's a point I hadn't considered!
The majority of the manky caps have been replaced with new or used (but working) 1970s/80s caps. Next up: rusted pots
By the way, one of the tracks has lifted slightly, and another one right next to it has had a "blob" burnt right off by my iron. What's the best way of repairing minor PCB track burns like this? Scraping the copper down and then re-laying the track?
Try scraping any resist off, going back beyond the lifted portion to an undamaged area, then lay a suitable length of tinned copper wire over the entire length and solder.
If you are replacing a component at the same time, as is usually the case, then bend the lead of the new component flat with the board and use that to repair the damaged track, rather than using another piece of wire.
If the track is only a short piece without enough of it remaining glued to the board to hold down the repair, consider removing the entire length of track and replacing with wire - insulated, if necessary.
Really it is up to your judgement to do what is best to restore the set to working condition, the important thing being that the repair is sound and unlikely to cause problems of its own.
When all else fails, read the instructions
