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Old dig. EchostarDSB1000Ci2 ... absolutely dead?
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<blockquote data-quote="nopfusch" data-source="post: 130758" data-attributes="member: 195487"><p>As I said Llew, I appreciate any suggestion and recommendation, no - no burnt components. </p><p></p><p>No components, neither the PCB show any “burn” marks, just a slight de-coloring of the PCB itself. Looking at the SMPS-PCB, no-one would guess that this receiver is >7 Years old and lets say 60% of its age in use. </p><p>That’s why I’m concerned, that there is may be still a problem within the tuner. The 2 voltage chips getting warm, but the main board shows also no heat marks, e.g. those chips got always warm. </p><p>I have not checked the output with the oscilloscope. May be the output voltage oscillates. Then they get also warm. Tomorrow 1st thing to do. </p><p>Just find below an extract of the e-mail, I’m sending as reply to the Service dept. of Echostar. They wrote, they can’t give me any schematics, but they do want to send me an EPROM (?).</p><p></p><p><span style="font-family: 'Times New Roman'"><em>After building for all supply voltages a dummy load (just to draw 50-100 m Amps or so), I connected that dummy load to the SMPS. Still no output, as I actually have expected. I know from other SMPS that some “kick-off” is required to start a SMPS. I discovered then the PCS terminal (SMPS) needs a positive signal (from the always +5V, clock supply ) and then all voltages are come ON. If any of the voltages (except the +5V for the clock) is missing or too low, the SMPS switches off. That was all tested with dummy loads.</em></span> </p><p><span style="font-family: 'Times New Roman'"><em>Correction to my 1st report: after power-ON the receiver starts a 2-5 second internal test and does not start scanning.</em></span> </p><p><span style="font-family: 'Times New Roman'"><em>Now in tedious work I discovered, although the supply to PCS was there, all voltages switched off just when the tuner became power, i.e. after 2-5 seconds after powering ON.</em></span> </p><p><span style="font-family: 'Times New Roman'"><em>But all components in the SMPS measured statically OK. Then I saw on the Oscilloscope that the +8V breaks down (a few milli seconds) <strong>before</strong> the signal to the PCS terminal was lost. Here was a problem. Low power Transistor Q2 (D2058) in the SMPS lost its gain and could not produce the required +8V under load. The +8V feeds the +5V voltage regulator for the tuner.</em></span> </p><p><span style="font-family: 'Times New Roman'"><em>This took me about 20 working hours to find out. I changed the transistor and the receiver works now again. Only the two positive voltage regulators (Q102, Q103) for +5 and +12 Volts, getting quite warm. On the +5V 289mA (dissipation: [8V-5V]x0.3A=0.9W)are drawn only. At the 12 V stabilizer chip 140 mA (dissipation: (21V-12V)x0.14A=1.26Watts). I mounted both on a common hetasink and I installed a small fan (from a PC) to keep the heat down. Are the currents +/- correct as measured?</em></span> </p><p><span style="font-family: 'Times New Roman'"><em>289 mA on the +5V supply to the tuner is that in order?</em></span> </p><p><span style="font-family: 'Times New Roman'"><em>140 mA on the +12V supply to the tuner is that in order?</em></span> </p><p><span style="font-family: 'Times New Roman'"><em>Only all stored satellite and channel data from 18 satellites seem to be vanished. Maybe some are still there – I have not thoroughly checked all satellites/channels.</em></span> </p><p><span style="font-family: 'Times New Roman'"><em>I don’t know why Echostar wouldn’t supply the schematics for a product, which is >7 Years old. And if the receiver is once really irreparable, I could only buy here a competitors product.</em></span> <span style="font-family: 'Times New Roman'"><em>It is therefore in Echostars interest, that I have as long as possible an Echostar 'working' at home.</em></span></p><p><span style="font-family: 'Times New Roman'"><em>So I can’t see any logic behind this. I accept, you can’t send the schematics from a current marketed product. Please re-view your decision.</em></span></p><p></p><p>So I have to watch those chips and tuner. And lets try to do some programming tomorrow. And then w'ill see if my repair was a lasting success.</p><p>Thanks Llew and Peter for your contributions </p><p></p><p>nopfusch</p></blockquote><p></p>
[QUOTE="nopfusch, post: 130758, member: 195487"] As I said Llew, I appreciate any suggestion and recommendation, no - no burnt components. No components, neither the PCB show any “burn” marks, just a slight de-coloring of the PCB itself. Looking at the SMPS-PCB, no-one would guess that this receiver is >7 Years old and lets say 60% of its age in use. That’s why I’m concerned, that there is may be still a problem within the tuner. The 2 voltage chips getting warm, but the main board shows also no heat marks, e.g. those chips got always warm. I have not checked the output with the oscilloscope. May be the output voltage oscillates. Then they get also warm. Tomorrow 1st thing to do. Just find below an extract of the e-mail, I’m sending as reply to the Service dept. of Echostar. They wrote, they can’t give me any schematics, but they do want to send me an EPROM (?). [font=Times New Roman][i]After building for all supply voltages a dummy load (just to draw 50-100 m Amps or so), I connected that dummy load to the SMPS. Still no output, as I actually have expected. I know from other SMPS that some “kick-off” is required to start a SMPS. I discovered then the PCS terminal (SMPS) needs a positive signal (from the always +5V, clock supply ) and then all voltages are come ON. If any of the voltages (except the +5V for the clock) is missing or too low, the SMPS switches off. That was all tested with dummy loads.[/i][/font] [font=Times New Roman][i]Correction to my 1st report: after power-ON the receiver starts a 2-5 second internal test and does not start scanning.[/i][/font] [font=Times New Roman][i]Now in tedious work I discovered, although the supply to PCS was there, all voltages switched off just when the tuner became power, i.e. after 2-5 seconds after powering ON.[/i][/font] [font=Times New Roman][i]But all components in the SMPS measured statically OK. Then I saw on the Oscilloscope that the +8V breaks down (a few milli seconds) [b]before[/b] the signal to the PCS terminal was lost. Here was a problem. Low power Transistor Q2 (D2058) in the SMPS lost its gain and could not produce the required +8V under load. The +8V feeds the +5V voltage regulator for the tuner.[/i][/font] [font=Times New Roman][i]This took me about 20 working hours to find out. I changed the transistor and the receiver works now again. Only the two positive voltage regulators (Q102, Q103) for +5 and +12 Volts, getting quite warm. On the +5V 289mA (dissipation: [8V-5V]x0.3A=0.9W)are drawn only. At the 12 V stabilizer chip 140 mA (dissipation: (21V-12V)x0.14A=1.26Watts). I mounted both on a common hetasink and I installed a small fan (from a PC) to keep the heat down. Are the currents +/- correct as measured?[/i][/font] [font=Times New Roman][i]289 mA on the +5V supply to the tuner is that in order?[/i][/font] [font=Times New Roman][i]140 mA on the +12V supply to the tuner is that in order?[/i][/font] [font=Times New Roman][i]Only all stored satellite and channel data from 18 satellites seem to be vanished. Maybe some are still there – I have not thoroughly checked all satellites/channels.[/i][/font] [font=Times New Roman][i]I don’t know why Echostar wouldn’t supply the schematics for a product, which is >7 Years old. And if the receiver is once really irreparable, I could only buy here a competitors product.[/i][/font] [font=Times New Roman][i]It is therefore in Echostars interest, that I have as long as possible an Echostar 'working' at home.[/i][/font] [font=Times New Roman][i]So I can’t see any logic behind this. I accept, you can’t send the schematics from a current marketed product. Please re-view your decision.[/i][/font] So I have to watch those chips and tuner. And lets try to do some programming tomorrow. And then w'ill see if my repair was a lasting success. Thanks Llew and Peter for your contributions nopfusch [/QUOTE]
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Old dig. EchostarDSB1000Ci2 ... absolutely dead?
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