Head 2 has an error rate of 20, even after cleaning thoroughly

Hi ,
I am a very proud owner of a DCC730. It plays DCC cassettes perfectly, no dropouts whatsoever. But when put in service mode the display shows 00 01000000. The next display indicates head 2 with an error rate of 20. All other heads have an error rate of 00, except for head 9 which has an error rate of 50, but I’ve read that is normal with your own recordings.

I have cleaned the heads several times with a cotton swab drenched in IPA but it did not improve one bit. The capstans are clean like a mirror and I also replaced the pinch rollers.

I’ve read that at an error rate of 20 the head isn’t defective but needs cleaning. But my intensive cleaning doesn’t improve it. I did not fiddle with head azimuth because I have absolutely no dropouts.

Is there another way to check if a head is defective, worn, or just dirty? I tried to take a macro picture of the head but couldn’t succeed.
Could head 2 be worn while other heads are in perfect condition?

Are the pinch rollers okay?

Thanks for your quick response Max, the pinch rollers are replaced last week (and brand new).

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Yes, a single damaged track is more likely than multiple tracks. If you are careful with it and don’t use any further analog tape it won’t be too much of a problem for you except when a tape is already damaged. One fully dead track is the maximum the error correction can handle so there is still some room.

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Hi,
If the track keeps showing a 1 or F and you have replaced the pinch roller, the only potential other problem could be the TDA read amplifier. I have not seen those fail on a 730 yet however.

My best educated guess is that this track might be damaged indeed.

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Thanks for all information!
Meanwhile I noticed the smd caps on the left side of the head amp board get really hot (>40 C). Is this normal or should I replace them?

I believe they do get hot normally.

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I rarely have used analog tapes in my DCC, so I really would like to check if the read amp could be defective instead of the head.

Can I -temporarily- exchange the read write board with the one from my DCC951?
Or should I better start measuring the head signals?

If you don’t record, it should be possible. But don’t take my word for it, wait for @drdcc or @Jac.

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Playback should work and it is a good idea to see if it is the head, causing the problem.

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Thanks! I’ll keep you posted!

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I tried the head amp board from a defective 951 with 111111111 head errors in my 730 with head errors 010000000. The head amp board worked well, but in service mode gave the same errors as before.

Vice versa I put the head amp from my 730 in the defective 951 but that gave the same errors 111111111, so it looks like the head from my 951 really was defective.

And then it happened… After switching back the boards to keep the correct adjustments for my 730, the 730 now also shows 11111111 errors on all heads :frowning:

So I ended up with both players in head errors. I really don’t know what I did wrong to blow the head (if that’s the case). I worked anti-static (bench and wrist) and was very careful, also while handling the connectors.
I can not think of anything what I could do better when changing the head amp board. Are they really that sensitive?

Anybody had the same experience and/or any ideas before I bin them?

R.I.P DCC head. I did not know that your 951 was all-dead so likely the read-write board did some sort of damage.

Thanks Max, but our messages crossed.

I couldn’t let go and would not believe this happened to me.
First I tried an analog co2 cassette and it played on the left channel only. Then I started moving the white flat cable and the right channel jumped in.
But when releasing pressure on the flat cable the right channel disappeared again. So I checked and there was some tension on this flat cable, probably causing an open on the connector it was seated in.
So I got rid of the tension by slightly bending te flat cable to release tension and voila DCC sound returned!

Sorry to have bothered you, but I thought I’d share this because it shows how careful one must be when working on these delicate sets.

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