Original List Price : £000.00 ( to be ascertained)
Integrated Circuits: Yes
This is a recent addition, in immaculate condition. I powered it up and it instantly came on. My first observation was the raster seemed rather washed out, I expected to see the usual no signal static snow. I then connected a test signal and started tuning in. At which point there was a medium loud PHUT….. and a plume of smoke.
I believed this was the across the line mains filter cap expiring, as the set continued to happily work and the smoke soon dissipated. When I checked, indeed it was one of those RIFAs.
I continued to tune and eventually found a very poor rolling picture of the test signal.
As I suspected, the washed out blank raster I first saw doe indicate a fault. The brightness, contrast and colour controls appear to have no effect on the picture. Looks like I have a fault in the brightness circuit.
I checked the voltage out of pins 11 and 7 of the TDA3561A, they were correct. I also checked the brightness control varies in voltage swing, it does low is 1.7V and high is around 7.5V
GEC McMichael Full Circuit; Click on Image To Enlarge, Then Click Again To Zoom
All is pointing towards the TDA3561A being at fault, which seems unthinkable. These ic’s were so reliable back in the day, but we are talking 36+ years later, so I guess it cannot be ruled out.
As Sherlock might once have said, “When you’ve eliminated all the probable cause of your fault, what remains, however improbable, must be the cause.”
Watch this space!
Well, after 37-years I guess anything is possible, and we have to rewrite the book on reliability of once bulletproof components. The TDA3561A had developed a fault, a replacement fitted and normal service is resumed.
The remote control for this set had long been lost, however, I could not believe my luck. I looked on eBay and there was not only one but two GEC McMichael remotes up for sale. One was ratty, with most of the control identifiers rubbed off. The second, was in pristine condition, so I shelled out £25, and it arrived today, and it works. Now I can at least access Teletext functions as well as all the usual TV options.
The TV is now complete, I also have almost the exact stand it would have come with and a GEC McMichael CED disc player to go underneath. I’m very pleased with this and the repair, it will make a nice addition to the 80s section of the museum.