When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Bought a Sun 1115 analyzer, and Sun VAT-40. Cleaning the switches corrected sticking problems. But the scope comes on for about 5 seconds then goes black. Anybody in Fort Worth area know how to test the circuit boards, or know which board is the problem? Replacements are available.
I doubt yhis helps too much, but Sun Electronics was purchased by Snap On toola back in 1992. I have had Snap on technicians service older Sun equipment, such as alignment machines in the past. Possibly yhe VAT 40 is still servicable, but I doubt the scope will be. Call their service line.
I found all the boards online. It;s just knowing which one is the problem. Each one cost more than I paid for the machine.
The boards can also be repaired.
Bought a Sun 1115 analyzer, and Sun VAT-40. Cleaning the switches corrected sticking problems. But the scope comes on for about 5 seconds then goes black. Anybody in Fort Worth area know how to test the circuit boards, or know which board is the problem? Replacements are available.
Does any of your SUN documentation include schematics of either piece ?
Sounds like you have access to the circuit boards... Most simple thing to so is look for a "popped" capacitor. They are usually easy to spot, the top will be rounded. And look for corrosion on the circuits.
Example: You can see the rounded top of the one in the middle.
Sounds like you have access to the circuit boards... Most simple thing to so is look for a "popped" capacitor. They are usually easy to spot, the top will be rounded. And look for corrosion on the circuits.
Example: You can see the rounded top of the one in the middle.
That is good information I was wondering how to identify the bad ones without removing from board to test. I've decided to send the four questionable boards to someone that can put them in a working machine to identify problem board.
I still have a sun scope that was being thrown away that works great and we use it quite often, but they are getting hard to find. There are some more modern ignition scopes such as the Bosch MTS 5200 that can also allow you to look at the vacuum pulse of each cylinder as the engine is running and do automatic cylinder kill and then display how well each cylinder is operating. I am sure there is even more modern ignition scopes on the market new and used
Capacitors do not age well. Many who refurbish older stero equipment replace capacitors first. If u can do the soldering, it is a cheap fix.
^^^THIS^^^
As well as caps in guitar/bass/keyboard amplifiers.
MANY brand new amps/pre-amps continue using vacuum tubes and caps; Many audiophiles and musicians prefer Tubes over solid-state..
The brand name & quality of cap matters as well.
I still have a sun scope that was being thrown away that works great and we use it quite often, but they are getting hard to find. There are some more modern ignition scopes such as the Bosch MTS 5200 that can also allow you to look at the vacuum pulse of each cylinder as the engine is running and do automatic cylinder kill and then display how well each cylinder is operating. I am sure there is even more modern ignition scopes on the market new and used
I grew up on Allen Smartscope, even worked for SPS when emission testing began in Houston. If I ever find a Allen, or Bear I will jump on it. The Sun I have is just basic diagnostics. No relative compression.
Sounds like you have access to the circuit boards... Most simple thing to so is look for a "popped" capacitor. They are usually easy to spot, the top will be rounded. And look for corrosion on the circuits.
Example: You can see the rounded top of the one in the middle.
Originally Posted by Rebelyell
^^^THIS^^^
As well as caps in guitar/bass/keyboard amplifiers.
MANY brand new amps/pre-amps continue using vacuum tubes and caps; Many audiophiles and musicians prefer Tubes over solid-state..
The brand name & quality of cap matters as well.
The capacitor shown bloated above is an electrolytic capacitor. The life span of electrolytic caps are not very long, a few decades at best. This is why a lot of vintage electronic equipment doesn't work anymore. They use a gel or liquid (sometimes a solid) as the electrolyte. Over time they dry out and quit working. They are also poled. If you connected it wrong it will blow up, ask me how I know. Ceramic and other cap construction are more robust but the capacitance is usually reduced.
Glad you got your machine running.
After board repair adjustments would jump around. Testing found all potentiometers had open spots. Replaced all of them and scope and meter adjustment is smooth and easy. Also has 2 cylinder setting. Need to thin out garage.
Sun Engine Scope
