Re: Analogue monitor board repair

2016-11-07 Thread Adrian Graham
Hi folks, Replying to myself here since I've had a bit of a breakthrough but not in the way I'd have liked. A fellow collector who also got one of these machines at the same time opened his up and there was an extra little bridgeboard piggybacked off some resistors next to the teletext display

Re: Analogue monitor board repair

2016-10-31 Thread Adrian Graham
On 31/10/2016 23:14, "drlegendre ." wrote: > "Hence the question - am I wasting my time without a schematic for this > analogue board?" > > Might be helpful if you mentioned exactly what is or isn't wrong with the > unit.. describe the symptom(s), etc. I thought I'd ask

Re: Analogue monitor board repair

2016-10-31 Thread Adrian Graham
On 31/10/2016 22:22, "Peter Coghlan" wrote: >> >> Before I replaced the failed potentiometer (new one seen top left) the >> display looked like its horizonal hold had gone so I reasoned that's what >> the pot controlled. I can *nearly* get a steady picture but the

Re: Analogue monitor board repair

2016-10-31 Thread Adrian Graham
On 31/10/2016 22:29, "tony duell" wrote: > >> Before I replaced the failed potentiometer (new one seen top left) the >> display looked like its horizonal hold had gone so I reasoned that's what > > OK... The TDA1180 is the horizontal oscillator, etc, IC. It's

Re: Analogue monitor board repair

2016-10-31 Thread drlegendre .
"Hence the question - am I wasting my time without a schematic for this analogue board?" Might be helpful if you mentioned exactly what is or isn't wrong with the unit.. describe the symptom(s), etc. On Mon, Oct 31, 2016 at 1:44 PM, Adrian Graham wrote: > Folks,

RE: Analogue monitor board repair

2016-10-31 Thread tony duell
> Before I replaced the failed potentiometer (new one seen top left) the > display looked like its horizonal hold had gone so I reasoned that's what OK... The TDA1180 is the horizontal oscillator, etc, IC. It's well-known. Start by getting its data sheet. Indentify the horizontal oscillator

Re: Analogue monitor board repair

2016-10-31 Thread Peter Coghlan
> > Before I replaced the failed potentiometer (new one seen top left) the > display looked like its horizonal hold had gone so I reasoned that's what > the pot controlled. I can *nearly* get a steady picture but the brightness > is out as well, despite there being working pots for that and

Re: Analogue monitor board repair

2016-10-31 Thread Adrian Graham
On 31/10/2016 20:51, "tony duell" wrote: > >> My recent Executel addition has a 5" screen with associated analogue board >> that seems to be powered from a display chip I can't find any info on, and > > Well, it won't be _powered_ from that IC. My guess is that said

RE: Analogue monitor board repair

2016-10-31 Thread tony duell
> My recent Executel addition has a 5" screen with associated analogue board > that seems to be powered from a display chip I can't find any info on, and Well, it won't be _powered_ from that IC. My guess is that said IC provides the HSync and VSync signals, the video comes from other devices on

Analogue monitor board repair

2016-10-31 Thread Adrian Graham
Folks, I think I know the answer to this before I even ask, and that answer will be 'got a schematic' to which the answer's 'no and I doubt one exists any more' but... My recent Executel addition has a 5" screen with associated analogue board that seems to be powered from a display chip I can't