CT-F1250 Problems!!

[Tuquala]

Just finished rebelting a CT-F1250 I recently acquired, all went well. Since it would not play before, now I am finding some problems I would like some insight into. Can't think that these were results of the work I just did, but it's definitely possible!!

1. Playback is muted, no highs. Also varies in volume. One quirk is that for a second or two immediately after you push play, it sounds pretty good, definitely towards normal, then drops down to whatever level it decides it wants to be at!! This will happen each time you select play.

2. It will not record, is getting signal on the input, BUT it is erasing what was on the tape previously. No sound recorded at all.

3. I can hear a very faint, rythmic high pitched tone from the cassette mechanism area. This may be normal, since the cover is off and it may be blocked with the cover on.

4. Other questions of things I found when doing the belt replacement: One of the small ball bearings (left side) under the "head base holder" was missing, and I replaced it with a slightly larger one. I can't see any sticking or twisting of the head base when engaging play. Sound ok, no problem?? Also, the service manual shows a washer (??) between the "idler guide plate" and the spring but there is no part #, is there supposed to be one there??

Obviously this one has had work or whatever done to it before, that is to be expected on older stuff. I know that I will probably need to o/h the idler drive motor, but right now it is acting ok, maybe from finally being used again.

Thanks for you help in advance!!


Gerry

 

[pustelniakr]

Just finished rebelting a CT-F1250 I recently acquired, all went well. Since it would not play before, now I am finding some problems I would like some insight into. Can't think that these were results of the work I just did, but it's definitely possible!!

1. Playback is muted, no highs. Also varies in volume. One quirk is that for a second or two immediately after you push play, it sounds pretty good, definitely towards normal, then drops down to whatever level it decides it wants to be at!! This will happen each time you select play.

2. It will not record, is getting signal on the input, BUT it is erasing what was on the tape previously. No sound recorded at all.

3. I can hear a very faint, rythmic high pitched tone from the cassette mechanism area. This may be normal, since the cover is off and it may be blocked with the cover on.

4. Other questions of things I found when doing the belt replacement: One of the small ball bearings (left side) under the "head base holder" was missing, and I replaced it with a slightly larger one. I can't see any sticking or twisting of the head base when engaging play. Sound ok, no problem?? Also, the service manual shows a washer (??) between the "idler guide plate" and the spring but there is no part #, is there supposed to be one there??

Obviously this one has had work or whatever done to it before, that is to be expected on older stuff. I know that I will probably need to o/h the idler drive motor, but right now it is acting ok, maybe from finally being used again.

Thanks for you help in advance!!


Gerry

Missing, or incorrectly sized head plate bearing...serious problem. You must now fix that and see what remains.

Highs drifting off: tape being driven of to one side or the other. Thsi coudl be caused by the head plate bearing, or a variety of other causes: bad pinch rollers, binding pinch rollers (dried lube), incorrect pinch roller pressure, excessive, or insufficient take up torque, etc.

Enjoy,
Rich P

 

[Ed in Tx]

I think that bearing you replaced that's wrong size has the head plate and the plane of the head out of alignment raised up on one side, and out of alignment to the supply pinch roller arm probably causing the tape to skew. Have you looked at the condition of the tape for any edge wrinkling or damage after it's run through the deck? The supply side arm has a tape guide on it, and an adjustment nut that has to be aligned with a special mirror tape while it's playing so you can see the tape going across the heads. Not sure how one gets around not using one of those mirror tapes to align one of these machines.:scratch2:

 

[Eagle1]

Just finished rebelting a CT-F1250 I recently acquired, all went well. Since it would not play before, now I am finding some problems I would like some insight into. Can't think that these were results of the work I just did, but it's definitely possible!!

1. Playback is muted, no highs. Also varies in volume. One quirk is that for a second or two immediately after you push play, it sounds pretty good, definitely towards normal, then drops down to whatever level it decides it wants to be at!! This will happen each time you select play.

Spring tension is too light on either/both supply and take-up pinch roller assy's. From the factory these springs are anchored with a brown glue like adhesive to keep them from moving from their tested position. If the glue has been removed someone messed with it and the tension needs to be reset. There's no specific notch setting as each spring has it's own pull strength. I had to use a trial and play method since I didn't have a good spring tension force gauge, all tho a gun trigger pull gauge was suggested as reply in one of my posts. But as pustelniakr stated your over sized bearing may be hindering the transport movement and should be replaced first before proceeding. Also check to make sure the pinch roller assy's haven't been twisted or bent and the roller axles are seated properly. My take-up assy was both because the moron couldn't figure out how to remove them.

2. It will not record, is getting signal on the input, BUT it is erasing what was on the tape previously. No sound recorded at all.

Usually it's the other way from my experience with my 1250 but usually relates to tape path alignment and tension. Also check your tape head adjustment screw, it should have some green locktite applied from the factory. Someone may have messed with it. Nothing dire about it but don't mess with it until you have full playback from a good tape. Also check the nylon nut on the the supply pinch roller side. They tend to crack and loose their tensile stength and will back off screwing up the tape alignment over the heads. If they all check out then look into the PB/Rec muting circuit. A bad cap could be a culprit. I'd look for a blue Tantalum cap in the rec. mute circuit as they can be notorious for failure. Pioneer designation is a CSZA...

3. I can hear a very faint, rythmic high pitched tone from the cassette mechanism area. This may be normal, since the cover is off and it may be blocked with the cover on.

You're hearing the motor and transport drives. You hear lots of stuff with the covers and faceplate off.

4. Other questions of things I found when doing the belt replacement: One of the small ball bearings (left side) under the "head base holder" was missing, and I replaced it with a slightly larger one. I can't see any sticking or twisting of the head base when engaging play. Sound ok, no problem?? Also, the service manual shows a washer (??) between the "idler guide plate" and the spring but there is no part #, is there supposed to be one there??

If you can give me a more specific SM locatiion like 11.2 and part location #32 (from what I can see for the bearing)for each I maybe able to help you out from a parts unit I aquired. PM me if interested.

 

[Tuquala]

Thanks to all for your quick replies. I'll be rechecking things this afternoon after back from work.

Eagle 1: The ball is not going to be a problem, I will find a better substitute. The washer I mentioned (or lack of it) is on the parts breakdown in the SM on page 40 (Adobe Reader 9)/(page 45 on the Pioneer #'s in the left lower corner) and is shown between part #'s 5 & 6. The page #'s are from the downloaded SM from AK.

 

[Eagle1]

Eagle 1: The ball is not going to be a problem, I will find a better substitute. The washer I mentioned (or lack of it) is on the parts breakdown in the SM on page 40 (Adobe Reader 9)/(page 45 on the Pioneer #'s in the left lower corner) and is shown between part #'s 5 & 6. The page #'s are from the downloaded SM from AK.

Found it! I believe it's there to keep the spring from popping off. That's part of the braking mechanism and is missing from my parts unit. You might find a suitable metric washer at your local hardware store. Maybe someone can chime in with the OD and ID of the washer you're looking for.

 

[Tuquala]

Played some more this afternoon and evening. Found another ball almost the same size as the other, both of the spring plates seem to be about the same tension now. Actually didn't help any!! So then I decided to make a cheap cassette into a test piece that I could actually see the tape alignment better.

Found that the tape at the take-up capstan is moving towards the inside. Nothing looks bent or out of line. If I pull down very slightly on the pinch roller, tape will align again and sound comes back. Don't have a gauge so I am going to trial and error tomorrow. Also adjusted the tape guide on the supply side, that helped a minor bit. The adjustment nut is in good shape.

As to that washer on the brake plate, the belt instruction sheets from wwjoe.com don't show or mention it, and with the SM not giving a part #, I'm inclined to believe that it isn't a necc item. The spring is held under the plastic hook the plate slips over. If that isn't correct, maybe someone will have more info.

Thanks again for all help. Will keep posting till like new!!