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Question
Problem with Telex ACC-2000M fast copiers
| Posted By |
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Janelle Scotland |
| From TN |
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Lothiansound |
| E-mail |
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info@lothiansound.org.uk |
| When |
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20/10/2007 09:52:15 |
| Lothiansound is experiencing problems with Telex ACC-2000M fast copiers. We have two master units and six slaves. Copying from a brand new, branded tape master, Side B sound can be muffled while side A is clear. The heads on the copiers are cleaned after every session. We have carried out extensive tests in an attempt to identify the culprit but find the fault to be intermittent. Some runs, we now have to re-copy almost a third of the tapes. Can anyone help us?
Come and speak to me at the conference next week if you have any ideas. Thank you.
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| Posted By |
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BRIAN |
| From TN |
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NEWSPEAK |
| E-mail |
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N4BDW@BLUEYONDER.CO.UK |
| When |
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30/10/2007 17:18:39 |
| Is the same result using the tapes wound for TNs
in the master? Thinking here that these tapes are probably better suited/more resistant to heat.
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| Posted By |
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Jim Stewart |
| From TN |
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Hamilton Sound |
| E-mail |
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info@hamiltonsound.co.uk |
| When |
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01/11/2007 09:29:18 |
| Email below has also been sent directly to Janelle Scotland:
We don't have any direct experience of this particular Telex Model (currently we have Telex Xgen series and prior to that we had Wollensak's) but as we do most of our own copier maintenance our 'expert' should be able to help you - I'll ask him.
However, I have a few supplementary questions before I pass on your problem to him (because I know he'll ask me this anyway):
How old are your machines and, more importantly, can you provide some details on the number of duty cycles they have been through since pinch rollers and/or heads were last renewed?
Are your heads heavily worn (e.g. when you run a finger nail gently over the heads surface can you feel any ridge caused by tape wear).
When you clean your heads, do you also clean the capstan and pinch rollers?
What solvent do you use for cleaning (is it AF spray)?
When you experience the problems are all tape positions on all slaves on a particular Master/Slave combination affected.
If no to above, are all tape positions on any particular slave unit affected.
If no to above, does the problem only ever occur on specific tape positions or does it randomly occur on any.
Finally, are any of the copy tape positions on the Master Unit ever affected.
One or two personal thoughts I can throw in here relating to problems we have encountered in the past which may be worth considering:
The problem is symptomatic of poor tracking which in turn could be caused by head mis-alignment, worn pinch rollers or debris build up on the capstan (or any combination of these). Remember that build up on the capstan can be difficult to detect because it sort of 'bakes on hard' and gets 'polished' to the point where it can be virtually undetectable so very close examination using a powerful magnifier is essential.
We have found that AF spray and no doubt other 'so called' head cleaning fluids can seriously damage the compound material from which the pinch rollers are made. We now use only alcohol and even then very sparingly and rarely.
We have found that some of the head alignment locking nuts on some of our heads are ineffective (there seemed to be a bad batch passed through the Telex factory at some point when our units were made) so we have had to replace these where possible or accept that periodic re-alignment is necessary where not.
I presume your technicians have checked the interconnecting cables and plugs for signs of intermittent connection problems.
Slightly more unlikely but possible are 'dry joints' on the internal circuit boards. If you have, or can get, the workshop manuals on these copiers this can be fairly quickly checked over.
If you can answer the above I'll see if our guru can help.
Best wishes,
Jim
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| Posted By |
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Janelle |
| From TN |
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Lothiansound |
| E-mail |
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info@lothiansound.org.uk |
| When |
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01/11/2007 14:10:05 |
| We have used new black unbranded tapes and TDK branded tapes in our tests. |
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| Posted By |
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Janelle Scotland |
| From TN |
|
Lothiansound |
| E-mail |
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info@lothiansound.org.uk |
| When |
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05/11/2007 11:40:06 |
| I have tried to answer your questions to the best of my ability, Jim. I look forward to hearing what your expert has to say.
The "young" machines were bought in 1999, the others in 1998 and 1997! Approx. 450 tapes are copied per week. Two units were professionally overhauled 18 months and 1 year ago. I could not say exactly what was done to them.
I can not feel any ridge on the surface of the heads.
We do clean the capstan and pinch rollers along with the heads. We only use Isopropyl Alcohol on a cotton bud for cleaning.
No, all tape positions on all slaves on a particular Master/Slave combination are not affected simultaneously. Neither are all tape positions on any particular slave unit affected simultaneously.
The problem occurs totally randomly. When a position is poor on this run, it can be perfect on the next. Never are all tapes in any one run, nor all tapes from any one machine faulty.
Copy tape positions on the Master Unit can be affected but not exclusively.
If the problem is poor tracking caused by head mis-alignment, worn pinch rollers or debris build up on the capstan (or any combination of these) why on all or any of the machines at once?
The interconnecting cables and plugs have been checked but perhaps not as thoroughly as necessary. If the head alignment locking nuts needed adjustment/replacement, is it likely that the problem would be intermittent?
We just have the users handbook no workshop manual. |
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