- glass epoxy ? - 2 Updates
- Diffferent techniques in troubleshooting - 10 Updates
- Calculator button not working - 1 Update
| avagadro7@gmail.com: Dec 31 06:17AM -0800 recommend a glass epoxy for cracked halogen light covers ? |
| Fred McKenzie <fmmck@aol.com>: Dec 31 11:49AM -0500 In article <ed08d40b-16f6-4438-8fac-4f41eb383840@googlegroups.com>, > recommend a glass epoxy for cracked halogen light covers ? I think the temperature may be too high for epoxy. If the covers are plastic, perhaps a solvent can be found that will "weld" the pieces together. What about fiberglass tape? Fred |
| John Heath <heathjohn2@gmail.com>: Dec 30 04:10PM -0800 I remember working for a company that imported cheap radios. I took my seat with the other 20 or so techs repairing radios. Most quotas were in the 20 range while I was only repairing 3 or 5 radios a day. Thinking I would be handed my pink slip I asked the tech next to myself how he was repairing so many radios? He pointed to my draw where I had saves some diagrams off the back of some of the radios. There is your problem he said. You are over thinking wasting time. You can measure 6 transistors faster than you can think if they are RF , audio or IF. In short stop thinking and start measuring. When I looked around I could see that the other tech were measuring not thinking. I took his advise and my quota when up from 3 a day to 10. A lesson I did not forget and still use today. I would like to know if others have found this to be true. |
| John Robertson <spam@flippers.com>: Dec 30 06:09PM -0800 On 12/30/2015 4:10 PM, John Heath wrote: > I remember working for a company that imported cheap radios. I took my seat with the other 20 or so techs repairing radios. Most quotas were in the 20 range while I was only repairing 3 or 5 radios a day. Thinking I would be handed my pink slip I asked the tech next to myself how he was repairing so many radios? He pointed to my draw where I had saves some diagrams off the back of some of the radios. There is your problem he said. You are over thinking wasting time. You can measure 6 transistors faster than you can think if they are RF , audio or IF. In short stop thinking and start measuring. When I looked around I could see that the other tech were measuring not thinking. I took his advise and my quota when up from 3 a day to 10. A lesson I did not forget and still use today. I would like to know if others have found this to be true. Well, in my field (arcade game repairs - video, pinball, etc.) we (the industry) used to trouble shoot monitors looking for the exact problem. Then some lazy tech started simply replacing all the electrolytic capacitors in the monitors - and the service rate went from a few monitors a day to five or more. In 90% of the cases replacing the caps and the HOT (and fuse) fixed most problems, changing the caps, HOT and LOPT/Flyback fixed most of the rest. Leaving 5% as dogs that one could spend a day on - if the customer thought it was worth the money. Mr & Mrs. Gilbreth (Cheaper By The Dozen) who in their Time Management process would often watch the laziest employee as he (she) would usually have the best way of doing the job with a minimum of effort or fuss. John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| Fred McKenzie <fmmck@aol.com>: Dec 30 10:07PM -0500 In article <d1567cb1-cd2d-4fd7-be29-7de28d1a59ab@googlegroups.com>, > measuring not thinking. I took his advise and my quota when up from 3 a day > to 10. A lesson I did not forget and still use today. I would like to know if > others have found this to be true. John- What do you do when all the transistors are good? Back in the 60s I worked for a year as an electronics troubleshooter. As I recall, the quota was testing 80 circuit modules per day. The quota was how many modules were tested, not how successful was the troubleshooting of failed modules! Repair records traveled with each module. I noticed that other technicians would trace a signal, and have the first transistor replaced where the signal stopped. Sometimes the same transistor would be replaced multiple times. Once I noticed that the problem was actually caused by a wrong part, a backwards diode or parts mounted in the wrong holes, I learned to visually check the modules before testing. My quota increased dramatically. I suppose a quota system is necessary, but it does encourage shortcuts. Fred |
| "Ralph Mowery" <rmowery28146@earthlink.net>: Dec 30 11:20PM -0500 "John Robertson" <spam@flippers.com> wrote in message news:VaKdnbNpErDOExnLnZ2dnUU7-aWdnZ2d@giganews.com... > (and fuse) fixed most problems, changing the caps, HOT and LOPT/Flyback > fixed most of the rest. Leaving 5% as dogs that one could spend a day on - > if the customer thought it was worth the money. As always there are many ways to attack a problem. If equipment has a history of some part or parts failing , look at that first. Especially if it is easy to replace those parts and they do not cost very much. Then if it still does not work go on to other methods. At work we had some equipment that 99.9% of the time it was one of two things, About 80% was a relay, the other large percentage was a circuit board that we did not repair in house, but changed out. The relay was easy as it just plugged in. Took about 5 seconds to change. The board took about 30 minuits to change. For the ones that knew the equipment would take one voltage reading before changing the relay, for ones that did not know the equipment and called some one they were told to change the relay. For something like radios ( I repaired the CB radios back when they cost around $ 200 and up ) I used the devide by two method if nothing stood out at first glance. Start about half way and inject a signal or listen for a signal. From that point go about half way to the end and so on. |
| John Heath <heathjohn2@gmail.com>: Dec 30 10:19PM -0800 On Wednesday, December 30, 2015 at 9:09:28 PM UTC-5, John Robertson wrote: > (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) > www.flippers.com > "Old pinballers never die, they just flip out." A friend of mine has an old school arcade machine. No CPUs or monitors in this puppy. Just a pile of relays and paddle wheels. Great stuff. I could not find the tilt detector? I found a short cut for flat electrolytic condensers in monitors and switching power supplies. First check if condensers that are rounded on top. Failing this use an impedance meter to measure the condenser impedance in circuit without un soldering it. Not un soldering it saves a lot of time. Any condenser with a impedance higher than a few ohms at 10 KHz and you found your problem. The down side is they do not sell condenser in circuit impedance meters so you have to make it yourself. Not a big deal as it just requires 10 KHz at a low impedance with about 100 m volts then monitor the current. |
| Rheilly Phoull <rheilly@bigslong.com>: Dec 31 02:26PM +0800 On 31/12/2015 2:19 PM, John Heath wrote: >> "Old pinballers never die, they just flip out." > A friend of mine has an old school arcade machine. No CPUs or monitors in this puppy. Just a pile of relays and paddle wheels. Great stuff. I could not find the tilt detector? > I found a short cut for flat electrolytic condensers in monitors and switching power supplies. First check if condensers that are rounded on top. Failing this use an impedance meter to measure the condenser impedance in circuit without un soldering it. Not un soldering it saves a lot of time. Any condenser with a impedance higher than a few ohms at 10 KHz and you found your problem. The down side is they do not sell condenser in circuit impedance meters so you have to make it yourself. Not a big deal as it just requires 10 KHz at a low impedance with about 100 m volts then monitor the current. Google "blue meter" or "Bob Parkers ESR meter". |
| John Heath <heathjohn2@gmail.com>: Dec 30 11:05PM -0800 On Wednesday, December 30, 2015 at 10:07:51 PM UTC-5, Fred McKenzie wrote: > > others have found this to be true. > John- > What do you do when all the transistors are good? Good question. While the ohms meter is still in your hands from measuring the transistors you touch the volume control. If you hear a click from the speaker the audio is okay. Then the IF and RF with a RF injector probe. With practice it all happens so fast that you quickly know where the problem is. If it turns out to be a dog then the golden rule is switch your dog for someone else's dog. Often my dog is an easy fix for someone else and their dog is an easy fix for me. Not sure why it is like this. Maybe taking a fresh look at a problem from different shoes. > increased dramatically. > I suppose a quota system is necessary, but it does encourage shortcuts. > Fred Yes I know what you mean. With new boards anything can be wrong. Memorizing all the resistors . diodes and transistors can save a lot of time by quickly troubleshooting with your eyes only. |
| John Heath <heathjohn2@gmail.com>: Dec 30 11:16PM -0800 On Thursday, December 31, 2015 at 1:27:12 AM UTC-5, Rheilly Phoull wrote: > > A friend of mine has an old school arcade machine. No CPUs or monitors in this puppy. Just a pile of relays and paddle wheels. Great stuff. I could not find the tilt detector? > > I found a short cut for flat electrolytic condensers in monitors and switching power supplies. First check if condensers that are rounded on top. Failing this use an impedance meter to measure the condenser impedance in circuit without un soldering it. Not un soldering it saves a lot of time. Any condenser with a impedance higher than a few ohms at 10 KHz and you found your problem. The down side is they do not sell condenser in circuit impedance meters so you have to make it yourself. Not a big deal as it just requires 10 KHz at a low impedance with about 100 m volts then monitor the current. > Google "blue meter" or "Bob Parkers ESR meter". Nice find. Way better than my home brew ESR. |
| avagadro7@gmail.com: Dec 31 06:20AM -0800 use the Chevy Method....measure then replace the suspect area. |
| John Robertson <spam@flippers.com>: Dec 31 08:03AM -0800 On 12/30/2015 10:26 PM, Rheilly Phoull wrote: >> yourself. Not a big deal as it just requires 10 KHz at a low impedance >> with about 100 m volts then monitor the current. > Google "blue meter" or "Bob Parkers ESR meter". Indeed, I've been selling those meters since 1999 when I first starting chatting with Bob Parker (Dick Smith K-7204 kits in those days). Great ESR meter that works in circuit for roughly values between 4ufd to about 1000ufd. John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| mzenier@eskimo.com (Mark Zenier): Dec 30 07:36PM In article <rFAgy.373267$dK6.72081@fx42.am4>, >for the layout of the 3 pins - when I salvage them, I leave them on the >front panel PCB so I can trace the tracks and figure out which pin does >what. Digging out an old EEM catalog, the page for the Sharp modules has 9 different frequencies ranging from 32khz to 56.8 kHz. And I vaguely remember the datasheet for the Temic(?) integrated circuit sensors where the subcarrier frequency could be from 20 kHz to 95 kHz. Mark Zenier mzenier@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com) |
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