Derek92994's 700 Ser II White Oak conversion

[laatsch55]

Yeah, that's enough Darc..

 

[derek92994]

Yeah, that's enough Darc..

Picos Measure 0.7 ohms except for one which is 0.5

 

[laatsch55]

All 4?

 

[derek92994]

All 4?

Yes I measured 4 picos.

 

[laatsch55]

Ok....having 100 volts plus to both outputs could mean a low voltage section problem common to both channels. The low voltage section is in the middle of the control board. With the board remounted, we need to check all 3 legs of each TO-220 , the top and bottom one. You should have rail voltage on one leg, about .8 on the other and 19 volts on the other. Do you have mini grabbers for leads??

 

[laatsch55]

Also is one of the heatsinked TO-5's on the bottom of the board getting hot?

 

[derek92994]

Ok....having 100 volts plus to both outputs could mean a low voltage section problem common to both channels. The low voltage section is in the middle of the control board. With the board remounted, we need to check all 3 legs of each TO-220 , the top and bottom one. You should have rail voltage on one leg, about .8 on the other and 19 volts on the other. Do you have mini grabbers for leads??

Had to find the other camera, battery went flat.

How about these?

 

[laatsch55]

Darc, the center of the board section is wher we get +,- 20 volts for the low voltage section of the board from the 100 volts rail voltage. +,- 20 comes off the TO-220's through the TL-431(To-92) voltage regulators, then to each side of the board.

 

[derek92994]

I shall remount the control board and will use an infrared thermometer to check heat. How long to run it for before checking temperature?

 

[laatsch55]

Had to find the other camera, battery went flat.

How about these?

One will work to keep the negative lead on the busbar.

 

[laatsch55]

I shall remount the control board and will use an infrared thermometer to check heat. How long to run it for before checking temperature?

Use your finger on the heatsink..a minute will tell ya..

 

[derek92994]

Use your finger on the heatsink..a minute will tell ya..

There's a pair of both of these, both did not get hot.

Last power up the meters just pegged like crazy and I got smoke, but I don't know where it came from. I'm guessing the backplanes.

 

[derek92994]

I will investigate to see if I can find the burnt component.

 

[laatsch55]

Power down, check the big caps, demount the board and look for burnt stuff on the backplsnes...

 

[laatsch55]

Darc, I gotta get to bed bud. We;ll pick up tomorrow. I think we'll be better off if I get an assembled G board and send it to you. It's guaranteed bud, it'll be on me.

 

[derek92994]

Darc, I gotta get to bed bud. We;ll pick up tomorrow. I think we'll be better off if I get an assembled G board and send it to you. It's guaranteed bud, it'll be on me.

I am willing to pay for Cost and Postage of the board bud.

Thank you for your time Lee. I will take some pictures of the boards and post. Can't find any burn but there was definitely smoke.

 

[derek92994]

 

[laatsch55]

Man, I don't see anything smoked..

 

[laatsch55]

I did a shitty job of cleaning the topside of the backplanes...

One last thing tonight Darc. Check B+. B- voltages on the test points on the backplanes, minus on ground, plus on the B+, B- test points..

 

[laatsch55]

I am willing to pay for Cost and Postage of the board bud.

Thank you for your time Lee. I will take some pictures of the boards and post. Can't find any burn but there was definitely smoke.

I know you are willing, but your doing the work, I'll get it to you..