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RCA 64" Projection TV

I hate servicing projection sets, but agreed to this one simply because business is so slow these days. Right away it's obvious I will need some help: When I first tried the set, pushing power causes the set to cycle on and off very rapidly (for as long as power is held down). I went through the power supply and tried replacing some caps; now, pushing power starts the set for a half second and it shuts right down - and will not try to start again until the set is unplugged for a minute. Testing has ruled out HV shutdown. The first thing I intend to replace is the EEPROM. While I wait for that to be ordered, can you give me any other advice? The customer said the set would also go to a black-and-white picture once in a while, and turning it off for a few minutes would correct the problem (at least for a few more minutes). So I suspect there may be other problems waiting to be found, once the set is brought back to running condition. Or is that perhaps a fault of the EEPROM as well??

Reply to
Chris F.
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Does the EEPROM commonly fail on these? I don't think I've ever come across a bad EEPROM in a TV, not to say it doesn't happen, but it certainly wouldn't be my first suspect unless it's a known issue.

Reply to
James Sweet

With the exception of the tuner ground causing failure of the eeprom data on the direct view ctc177 series, I have never seen an eeprom failure in an RPTV set.

There is little real technical information in the OP to garner any kind of help. It might be best for the OP to post information like a trained, equipped, and qualified technician would.

Reply to
dkuhajda

Unhook the high voltage splitter input from the flyback, & if the unit comes on with filiaments, you have it. If this fails to get it going, the flyback may be bad, especially if nothing else is bad. The red wire next to the flyback can also make it look like the flyback itself is bad. Look for CRT coolant leaks ...many problems with these with leaks, & a lot more. Is it "squealing" while it's trying to start? You have a short, if so. Check the horizontal output, pincushion correction circuit, & convergence power supply. Hope this helps. EEPROM highly unlikely at fault, unless someone was at the unit, or if the tuner was really bad...solder connections, & left to long. Sky.

Reply to
Sky

I neglected to mention the chassis # - it is a CTC-169PT No evidence of coolant leakes at all, and I've tried to power it with the yokes & flyback lead disconnected. As I said before, I ruled out HV shutdown by disconnecting that lead to the TA8680 IC. I've replaced many bad EEPROMS on the CTC-175 series.... One other thing worth noting; with a VOM connected across the B+ supply, I noticed something odd; when the set is plugged in, instead of going directly to 150 volts or so, it goes to about 100 and slowly ramps up to 150 within

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Reply to
Chris F.
150 volts is too high. Do a google groups search for all the pertitent ctc169 information. 15V run diode problem, all the power supply capacitors, standby power supply voltages etc.

Set will still go into protect shutdown if the hv splitter is bad due to the power supply load. Pull the hv lead out of the hv splitter and check inside for carbon problems, typical additional failure after the smps was running too high as it is right now.

You also cannot run the ctc169 with the yoke leads disconnected, that too will cause immediate shutdown.

Reply to
dkuhajda

Set fixed - I replaced the three NTE 588 diodes in the switching power supply and everything seems great. Funny though, since the diodes checked OK on a DMM. Oh well now I know that for next time. Thanks to all for the advice.

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Reply to
Chris F.

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