Thanks, Ixnay, I will triple-check. As I said the AC connections are now small silver-plated bobbin/post-type terminals and solder flow on all off those looks good in person. All rectifier diodes were re-flowed top and bottom. Will check w/VOM, however.
I got my replacement transformer. Measured no-load on each half is 18.45 VAC, In contrast, the original one (identical 0218 model) measured 16.9v on one side and 17.4v on the other, so I've junked that and am using the new one. Perhaps at least part of the problem?
With R3 out, I just measured 24.45 across C5, which, BTW, does hold a charge and shows basically an open circuit on the VOM. Chrisng, this is below what you said it should be. What's my next move? I've already replaced those Schottky rectifier diodes (marked SR5100 M1[or I]G, as opposed to the original MUR410G). Or is 24.45 VDC good enough to proceed?
I got my replacement transformer. Measured no-load on each half is 18.45 VAC, In contrast, the original one (identical 0218 model) measured 16.9v on one side and 17.4v on the other, so I've junked that and am using the new one. Perhaps at least part of the problem?
With R3 out, I just measured 24.45 across C5, which, BTW, does hold a charge and shows basically an open circuit on the VOM. Chrisng, this is below what you said it should be. What's my next move? I've already replaced those Schottky rectifier diodes (marked SR5100 M1[or I]G, as opposed to the original MUR410G). Or is 24.45 VDC good enough to proceed?
Yes, please go ahead install R3 and the voltage across C6 should be close to 24.45V.
If R3 heated up at this point remove C6 and test again.
With R3 re-installed, VDC across C6 is 23.9. no heating of R3 at all
I checked the "good side. Measures 17.9VDC across C10. R3 heats up just a couple of degrees, no more. Assume this verifies the new semiconductors are fine.
At this point I assume it's safe to install the regulator and fire it up. Sound OK?
I checked the "good side. Measures 17.9VDC across C10. R3 heats up just a couple of degrees, no more. Assume this verifies the new semiconductors are fine.
At this point I assume it's safe to install the regulator and fire it up. Sound OK?
Before install regulator, use a jumper wire across D6, then measure the voltage across C8 and it should be equal to the voltage across C6 (should be about 23.9V) to ensure there's no short circuit after D6.
If voltage across C8 is OK, then go ahead install regulator.
If voltage across C8 is OK, then go ahead install regulator.
Everything was good with that last measurement. Both halves of the regulator putting out about 17.9 vdc. No resistor overheating.
Thanks for the help. It really made a huge difference. I have so much respect and appreciation for all of you on the forum.
I'll be posting the project on the Wayne's BA line stage thread when I finish assembly and testing.
Thanks for the help. It really made a huge difference. I have so much respect and appreciation for all of you on the forum.
I'll be posting the project on the Wayne's BA line stage thread when I finish assembly and testing.
