Huntron Pro Track 1 Model 20 - Display fault.

Started by jvthorsley, June 24, 2014, 04:23:50 PM

Previous topic - Next topic

jvthorsley

Hi Curtis
My Pro Track developed has a problem. Initially it was very intermittent but now quite solid.
At first the horizontal trace would occasionally come into a centre dot and go right off.
I used to open the unit up, check everything was plugged in, power back on and all appeared ok.
But now after the unit has been switched on for a short time the horizontal trace looses all horizontal drive, gives a bright centre dot for a short time them dies.
All the switch function lights appear to still work when this happens.
Have you any tips as to the most common cause of this fault?

Support

This is normally the high voltage power supply for the CRT.

jvthorsley

#2
Recently repaired my Huntron ProTrack 1 Model 20. Initially thought the EHT supply had failed but soon found this was at -1.3 KVDC as on the test procedure.
The loss of the CRT trace was caused by complete failure of the Electronetics (06-6066 B) DC to DC module.
This module has a 12 VDC input and should output 200 VDC and 9 VDC isolated supplies.
The 200 VDC is fed to the CRT supplies and the 9 VDC goes into a LT1086 regulator to supply the CRT 6.3 VDC heater supply.

I used a GP02R from Emco High Voltage Corporation to supply a 200 VDC @ 5 mA isolated supply.
And a TDA2-1212S from Tri-Mag a Curtis Industries Company to supply 12 VDC @ 200 mA isolated supply.
No other components were required and there was plenty of space to mount the two DC to DC modules with the Electronetics module removed.
Powered it up and it all worked as per the Huntron test procedure for the 06-3098 high voltage PCA.
Attached photo shows the two replacement modules in the position of the Electronetics module.

Curtis I had to severely crop the photo to come down to the max resolution allowed!

admin

Nice job, James. Thank you for sharing. Be careful around those exposed leads!  :)

Care to share an approximate cost for the fix?
The most important troubleshooting tool is your eyes.

jvthorsley

#4
Cost of components on the above repair job was:-
Sourced by Powerbox Craftec (www.crafttec.co.uk) in UK one Emco GP02R (200 VDC @ 5 mA DC to DC module) charge with carriage was £110.00.
And the Tri-Mag TDA2-1212S (12 VDC @ 200 mA DC to DC module) sourced from Digi-Key cost a total of £42.40 also from your side of the pond.
Both modules are isolated supplies fed from the one 12 VDC supply.
Sorry prices in ponds Sterling, but probably would be cheaper in $.
Photograph of faulty Electronetics module shown on attachment. The space taken up by this is now used for the two replacement modules.

admin

I bumped the attached image pixel dimensions to 2000px by 2000px.
The most important troubleshooting tool is your eyes.

jvthorsley

Thanks Curtis for increasing the resolution for photographs. Even allowed me to used a picture of my 1978 MGB GT.
Not quite Huntron equipment but certainly " Out of Production Hardware" !!!

admin

Hi James,
Any chance you could repost the power supply images discussed earlier in this thread?
Thanks!
Curtis
The most important troubleshooting tool is your eyes.

admin

#8
Here are the images of what James did to fix the HV power supply. Note the wiring and part numbers of the modules that replaced the old Electronetics module. With the exposed wires and high voltage, we suggest you exercise caution when the ProTrack is powered ON.




Thanks to James for the images.
The most important troubleshooting tool is your eyes.