Satellite Workshop 24

Customers!

The telephone rang and a voice said "I'm looking at your advert - 'Satellite receivers repaired for 39' - and I want to know what it would cost to fix my MSS200?"
"Erm.... 39" I replied.
"Oh, as much as that? Thanks." Click. Brrrrrrrrrrrr.
Immediately it rang again and when I picked up the receiver a voice said:
"I threw out the User Handbook for my SVS300 by mistake. Have you got one I can buy?"
"I have only my workshop copy."
"I've spent two hours on the phone. British Telecom gave me another number. I rang that and was given another number. When I rang that I was given the first number. Then I started phoning all the advertisers in "Wot? Satellite" magazine till someone suggested you might help."
"I have only my workshop copy," I repeated.
"Well, can you photocopy it and post it to me?"
"I suppose so, although that would be a breach of copyright, but if nobody actually stocks the original and if BT themselves can't help....."
"How much?"
"I guess ten pounds should cover it. I'll have to drive into town, pay the travel agent to use her photocopier, drive to the Post Office....."
"HOW much???!! " Click. Brrrrrrrrrrrrr.
These guys have no idea. I can usually earn around 1 per minute at the workbench. If I take the time to go off on a jolly jaunt in the van, I think they should pay me for a reasonable percentage of that time. This man had probably spent more than £10 in phone calls already. Ho hum.

Ferguson SRD6

"Installed it myself, I did, but I got problems, to be sure."
"Huh?" I turned around but there was nobody there. Just a Ferguson SRD6 on my counter and a woollen bobble hat.
The hat moved. "Installed it myself, to be sure."
I peered over the counter to be confronted by an extremely short person in a green anorak, green trousers and green bobble hat. Could this be my very first leprechaun? Perhaps not. He was wearing bicycle clips round his trouser legs.
"Hi. What seems to be the problem?" (I almost said "sonny.")
"No picture, to be sure. Will you be looking at it now or shall I wait outside? It's probably just the crystal. What time will it be? Where's the nearest pub?"
"It's in Church Street," I replied, answering the last question first," and it's three-thirty. Come back at five."
"God bless you, thur, and where would that be?"
"Well, Church street is easy to find," I replied. Turn left out of here and it's on your right just half a mile before you see the bus stop."
He accepted these misdirections with gleeful thanks and bobbed out of the shop. I carried the receiver into the workshop where I discovered there was no LNB voltage. Obviously it was switched "OFF" in the secret installation menu but, no, it wasn't! Pressing "menu" then "4" and holding "9" for five seconds revealed the LNB installation menu which showed the LNB voltage to be "ON." The Local Oscillator was set to "10.000."
I thought, perhaps, since he'd installed it himself, he might have shorted something out. In fact, there was a genuine fault which I traced to a surface mount transistor, TP59, a BC848. Replacing this got rid of the green screen and restored the picture. Channel one was tuned to Sky News. I looked at the channel frequency which was completely wrong for that channel. I was using a Universal LNB but the menu was set to 10.000. Somebody had retuned every single channel instead of setting the LNB local oscillator to 09.750.
I get a lot of enquiries about this model because it incorporates a 22kHz tone generator which is not mentioned in the on-screen menus or in the User Instructions. It actually works like this: You access the LNB installation menu, as I described, and you set the local oscillator to "00.000" which tells the receiver you are using a "Universal" LNB with 9.75 and 10.6 GHz local oscillators. Now, when you enter a channel frequency of 11.649 or less, the receiver assumes it's connected to an "Enhanced" (9.75GHz) LNB. If you enter a channel frequency of 11.650 or higher, the receiver switches on the 22kHz tone and assumes a 10.6 GHz local oscillator LNB. In this way the Hi/Lo band switching becomes automatic. A clever idea but I defy anybody to use it with an external tone-operated switching box! By the way, it took me an hour of poking buttons, with the oscilloscope attached to the LNB supply, to figure this out. Even the Service Manual fails to explain it clearly.

Amstrad SRD510

Four SRD510 receivers arrived from another shop which employs an "engineer." In fact I'm sure he has no "Eng." after his name and would be lucky to be classed as "technician." Judging by the state of the receivers, he never learned to solder.
The first one did not light up and the reason was immediately obvious: someone had fitted an IP3842 I.C. instead of a UC3842 or similar. Most 3842 power supply chips will work in this model but the "IP" version refuses to.
The second SRD510 was also "dead." A power supply kit had evidently been fitted but the UC3842 was the original one - easy to see because there was no brown flux around its solder joints. I fitted a new IC and the unit worked perfectly.
The third SRD510 lit up but the picture was intermittent. Tapping the receiver would make the picture come and go. I've seen this fault so many times that it now bores me! Capacitor C55 sits near the edge of the board and has one wire not soldered. It seems to me that the PCB was probably held in a frame for passing over the solder bath during manufacture. The frame caused "shadowing" of this particular capacitor wire and created a poor solder joint.
The fourth receiver failed to light up but my oscilloscope showed that the ouput was pulsing weakly. The output rectifiers were not short-circuit and replacing the primary capacitors failed to make any difference. Next stop was the transformer, itself, which was, indeed, the culprit. As I had no LLP001 or LLP004 transformer in stock, I used the LLP006. The LLP006 and LLP007, used interchangeably in the SRD540/545/550, give 28 volts for the tuning supply instead of 23 volts for the earlier models. I have used them to replace the LLP001/LLP004 without any apparent problems, although it's a good idea to replace all the power supply electrolytics at the same time. By the way, the additional voltage does not increase the tuning range of the SRD510.