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RCA CTC 177BH2, model 27GT613, excessive width and apparent pincushion problem

According to the customer this set went dead. I powered it up and it worked, although I noted a severe tuner shield problem. I repaired the tuner shield and the picture seems too large. The sound is OK though. There is also what looks like a slight pincushion problem or a bending on either side of the picture that looks like a sort of hourglass effect. I adjusted the vertical and the linearity looks good but the horizontal width adjustment between 0 and 15 does nothing. Other adjustments seem to work though. Should I suspect a corrupted eeprom given the severity of the shield problem, or is it more likely a bad component is causing adjustment 03 not to work? Thanks, Lenny Stein, Barlen Electronics.

Reply to
captainvideo462002
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Never adjust EEPROM unless your sure it's not an electronic problem! There is a large diode with ferrite beads on it, & a blue capaitor, in the pincushion circuit! It will "kill" the unit, if you don't fix it! CR 4101, & C 4100, or something. Not hard to find. Good luck, Rono.

Reply to
Rono

Change the Blue Box caps first then check the settings in eeprom chances are they are bagged. Change the eeprom also but write down the data first. Thats what I would do.

Reply to
kip

Thanks guys for the advice. I'm going to dig further into this thing this weekend. Lenny.

Reply to
captainvideo462002

I just thought I would ask. The area of the board under CR4403 and C4407 had a thick glue on it. Is that supposed to be there or did it perhaps leak out of the capacitor? I found that CR4403 was indeed shorted, and the capacitor, C4407 seems to make the ohm meter jump on high range when going across it but it looks like it could be slightly bulged. I can not confirm capacitance as I don't have a meter but I would like to replace it anyway. The diode seems to cross to an NTE 577 and the capacitor looks like a .047 400V NP? Is there anything special about these two components? Thanks once again in advance. Lenny Stein, Barlen Electronics.

Reply to
captainvideo462002

The NTE cross will not last in that location. Use only the equivalent RCA part number or exact oem replacement number off the part. I think the FR### equivalent has also been posted here a long time ago.

The capacitor has failed, very common, causes diode to short.

Reply to
dkuhajda

A thing I've seen before in these sets is that there are two capacitors effectively in series with the diode across one of them, and when the one capacitor opens up or drops value by an order of magnitude, the diode gets hit with more voltage than it can handle and breaks down. I'd be checking capacitor values in the area, or you may be blowing more diodes.

I've used FR307's with good results.

Reply to
Bill S.

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