Vintage Synth Repair

Probably normal and just doing a little too much work.  Often engineers design for potential low line voltage conditions (90 to 95 V), but with the normal or higher, the regulator must now drop more voltage across it, more Watts, more heat.


I would calculate the work(voltage drop x current) that it is handling against the specs sheet for that transistor.   Then again, it seems like most of the Alesis repairs that I have done often involve a shorted or partially shorted cap, which would draw more current and run hotter.


Yea, this is why we get those BIG bucks!


--------------------------------------------
On Fri, 5/27/16, Cosmic Fugue cosmicfugue@... [vintagesynthrepair] <vintagesynthrepair@yahoogroups.com> wrote:


 Subject: Re: [vintagesynthrepair] Alesis ion Q01 - power supply
 To: vintagesynthrepair@yahoogroups.com
 Cc: winking_n_nodding@...
 Date: Friday, May 27, 2016, 5:13 AM


  













 I haven’t measured its
 temperature as I do not
 have this meter.
  
 As soon as I switch off
 and touch it for 2
 seconds I do not burn my finger
 but wasn’t able to keep
 it on it either as it was
 too hot.
  
 I have now fitted the
 replacement with a small
 heat-sink but just the same it works too hot.
 Thanks for you
 help...
  
  


  

 From: mailto:vintagesynthrepair@yahoogroups.com


 Sent: Thursday, May 26, 2016 10:05 PM
 To: vintagesynthrepair@yahoogroups.com


 Subject: Re: [vintagesynthrepair] Alesis ion Q01
 - power
 supply
  
  


 How hot is it? 70C? 80C? Warm to hot is normal, burn
 fingers in 2 seconds is
 not.
 --------------------------------------------
 On Wed, 5/18/16, Cosmic
 Fugue cosmicfugue@... [vintagesynthrepair]
 <vintagesynthrepair@yahoogroups.com> wrote:

 Subject:
 [vintagesynthrepair] Alesis ion Q01 - power supply
 To:
 vintagesynthrepair@yahoogroups.com
 Date:
 Wednesday, May 18, 2016, 5:25
 AM


  







 







 Anyone
 has or has met
 with an Alesis ion
 (Q01)?
 I noted Q2=TOP223Y in
 the
 primary of SMPS runs
 extremely hot (caution: switch off!!)
 Is this
 normal? It has
 no
 heat-sink!
 cosmo







 



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