Schlumberger Solartron 7045

[Specmaster]

I have been working on a repair to the battery inverter board for this meter. When I purchased the meter it never had the inverter supplied with it although the battery holder was in place the board was missing and a link wire soldered across 2 of the header pins to make it run on mains.

I have since obtained an inverter board but it had blown caps and resistors which I have now replaced but there is a red lead coming from the main PCB board with a push on connector that connects to something and the only place that I can see is on the inverter there are 3 test point headers and this lead is long enough to just reach 2 of these TP2+ on the top left of the inverter or test point 3 at the bottom centre. I have a downloaded copy of the service manual but sadly it does not cover this the battery option in detail and there is no mention where this lead should be attached to.

Has anyone here have any knowledge of this meter at all and could advice where this lead is to terminated to?

[coromonadalix]

can you get us photos of where the wire start or originate ?

EDIT   find this service manual link : https://www.vintage-radio.net/forum/attachment.php?attachmentid=37182&d=1277138657

[Specmaster]

can you get us photos of where the wire start or originate ?

EDIT   find this service manual link : https://www.vintage-radio.net/forum/attachment.php?attachmentid=37182&d=1277138657

Thanks, I already have that manual though it mentions the batteries it does not provide detail. I will have to strip it right down to get access to the solder side of the main PCB as the lead goes though a hole and you can feel that it terminates somewhere else on the board. I was rather hoping that someone might have one of these and could pop the hood and have a look at where the free end was connected to on the inverter?

[pigrew]

I don't know if it will help, but I found a photo of the meter with a battery installed .

[Specmaster]

I don't know if it will help, but I found a photo of the meter with a battery installed .

Yeah, thanks, I found that as well but it's only a thumbnail quality and blowing it bigger means that the quality is greatly diminished so the cable can't be seen.

[Specmaster]

Here is a couple of photos that show the red cable in question and its location within the meter itself.

[coromonadalix]

is it going to r22 or r99   that could be your hint ??  or it is an selection wire between b1 thru b10,  that would be logical the way i see it ??

[coromonadalix]

okay i see the b1 thru b10 are test points of all the supplies found in section 2-9

we have to know where this red wire is connected to ... before doing anything else

If you could probe on witch part it goes

[Specmaster]

is it going to r22 or r99   that could be your hint ??  or it is an selection wire between b1 thru b10,  that would be logical the way i see it ??

The red wire is actually soldered onto R102, also shown as Terminal Z on schematic that feeds power to the front panel via Y and Z, I'll post a photo soon.

[Specmaster]

Here as promised are the photos of where the red wire connects on the main pcb, now I'm even more confused. As you can see that pad is connected to the terminal "Z" white wire to the left of it and goes off to the front panel.

[coromonadalix]

on page 32

The 70457501 section in hashed lines, near the 70457502 inscription you have the Y and Z named wires, you have the r102 10 ohms resistor, the resistor is between sw1 A2 pin and sw1 A4 pins.


In section 4 of the manual you have some theory of operations ,,,, reading it would give you some hints.

...  switching an unregulated supply or the regulated +5v  for the battery pack if installed ??  i think for the charging mode when the meter is powered off, the trickle charge or the supply charge, section 4,3,2



As i see it in the same page (p32), you have two similar sections /revisions made with different parts, an 3 pins regulator lm340, and the other made with transistors and a op amplifier

Your first post picture is the dc/dc  70457704 pc board, i would not connect anything on tp3, tp2 is the positive side of the battery pack.


I finally think the red wire may have been added to do something or bypass some part of the dc/dc board and go straight to the battery ?, since you wrote the board wasn't there when you got the meter, and the battery holder casing was there,   the only logical place it would go is tp2, it may had another kind of battery installed ??

I don't like this wire at all, you should be very careful,  i would remove it, there only the Z wire going to the front panel, all the other pcb traces are between the sw1 switch.

The 7045702 board is the front display, the Y and Z wires goes to an D44 led    page 25  diagram 2.4

The B1 thru B10 are the dc/dc converter outputs / connection when inserted, i may have made a bad deduction, on the previous post

[Specmaster]

on page 32

The 70457501 section in hashed lines, near the 70457502 inscription you have the Y and Z named wires, you have the r102 10 ohms resistor, the resistor is between sw1 A2 pin and sw1 A4 pins.


In section 4 of the manual you have some theory of operations ,,,, reading it would give you some hints.

...  switching an unregulated supply or the regulated +5v  for the battery pack if installed ??  i think for the charging mode when the meter is powered off, the trickle charge or the supply charge, section 4,3,2



As i see it in the same page (p32), you have two similar sections /revisions made with different parts, an 3 pins regulator lm340, and the other made with transistors and a op amplifier

Your first post picture is the dc/dc  70457704 pc board, i would not connect anything on tp3, tp2 is the positive side of the battery pack.


I finally think the red wire may have been added to do something or bypass some part of the dc/dc board and go straight to the battery ?, since you wrote the board wasn't there when you got the meter, and the battery holder casing was there,   the only logical place it would go is tp2, it may had another kind of battery installed ??

I don't like this wire at all, you should be very careful,  i would remove it, there only the Z wire going to the front panel, all the other pcb traces are between the sw1 switch.

The 7045702 board is the front display, the Y and Z wires goes to an D44 led    page 25  diagram 2.4

The B1 thru B10 are the dc/dc converter outputs / connection when inserted, i may have made a bad deduction, on the previous post

You are indeed quite correct, I had already deduced that the Y & Z wires are for the D44 charging LED indicator in the front display, it's the lower of the 3 LEDs.

I traced the circuit through the SW1 contacts back to B7 of the headers to connect to the inverter board when plugged in.  B7 and B6 currently bridged out to bypass RL150 on the inverter so it will run from the mains supply.

So I had decided to remove the connection from R102 and remove the red wire completely as I cannot fathom out what this is doing unless it was being used as an indicator to show the state of the battery when off and disconnected from mains, i.e., no LED means battery is dead maybe if the other end was connected to TP2.

I decided to test out the inverter open circuit by connecting a regulated 5v supply as mentioned in the manual and it drew 1.4A, way to much for open circuit and C158 (22uF @16V) is shorted so I'll replace this next (may have to use a electrolytic here as I think I only have 10uF 25V tants in stock).

Once this is done, if no further problems with inverter are found, I'll remove the bridging link on B7 and B6 and put the inverter back in see what happens. I don't have any batteries to fit but it should default to mains supply with no batteries fitted.