|NOTES||This little telly wants to be a 22" colour set when it grows up.
Without the carry handle to scale it by, it would indeed look like a big
The circuit was a bit of a suprise. Plenty of silicon about, both in integrated circuits and in the lower power transistors, but why the use of the ye olde germanium AU113 in the line output ?
|SERVICE DATA||The chassis looks the same as that for the plastic-cased model MS1212 which is covered by trader service sheet #3128.|
|CURRENT STATE|| Very clean
and tidy. Rather ominously, one of the 2.5A anti-surge fuses was bodged
with an extra bit of wire. Thoughts of trouble ahead I thought. Removing
the wire revealed the fuse was intact.
After checking for shorts and checking the various diodes (particularly in the LOP stage) revealed nothing untoward. So next the CRT base was removed ; like a number of this type of set (including the earlier Philips TVette) the power supply has a linear regulator. If this is faulty then a lot of volts could be shoved into the CRT heater, which would be bad news. With the tube base well wrapped in insulation to avoid possible accidents, power was gradually applied. No smoke, no mains hum, in fact, nothing! There was ~16V DC at the battery input terminal at the back of the set but not on the timebase board. I now know why the fuse had been bypassed - it was intermittent ! Temporarilly replacing the 2.5A anti-surge with a 2A fuse and hey presto we got sound. Checking the voltage regulator showed it was dropping at least 4 volts, so it was power off, replace CRT base, switch on and behold a picture.
Off-station, the picture looked like it might have fold-over at the bottom where there was a bright bar. However this dissappeared when tuned to a station - is this normal ?
The picture is quite good (the crap photo was the best I could get out of my crappy Minolta camera) although there does seem to be faint traces of flyback lines - but no teletext lines.
|WHERE FOUND||BVWS July 2004 Wotton Basset bring-and-buy stall for six quid.|
Rear cover folds down to reveal two main PCB's, the one on the
left (with all the I.C.s) being the tuner and I.F. circuitry and the
one on the left the timebases.
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THE TELLIES GALLERY
15th July 2004