Philips B3X85U troubleshooting

[Abraham]

Ok, the voltage we use here in Panama (Central America), is 110 -120V 60 cycles.
The radio is set on the back to 110v. The measurements used on my multimeter was set to DC voltage. The capacitors on the big can of the chassis were changed, I measured them and the measured one of them 101v and the other 124v.

All valves are lit. The resistor R15 measures 230 on the meter set at 2000k. The speaker on the meter set at 2000k started measuring 640 and goes up to 1800 and fluctuates from 1740 -1800 and sometimes goes even higher.

[Steve_P]

Is this the speaker or the output transformer. The speaker goes to a transformer in most cases, but not in some Philips sets. Has it got one on this set?

This transformer is on the chassis or mounted on the speaker itself. Those readings are a bit worrying. Have you checked the transformer secondary or the speaker?

Cheers,

Steve P.

[Abraham]

The readings were taken on the speaker. The transformer is on the chassis.

[Abraham]

How do I measure the +, ++, +++ that Graham mentions in post 55?

I had measured the caps C1 and C2 with the negative probe on the chassis and one cap measured 101v, the other 124v.

[geofy]

Across the speaker tags you should measure (with set turned off) 5 Ohms approximately with the speaker disconnected. The transformer secondary will also have a low reading if it is intact, this also has a tapping that goes to a tone corrector C28 which gives negative feedback to the grid of the output valve via R52, R21.You have already measured + at C2 150V (101V) and +++ at C1 185V (124V). ++ is the other end of R1.

But please be careful this is not the ideal set for a beginner, make sure the mains neutral is always going to the chassis.

[robjkmannering]

Could the output transformer/speaker be eliminated from fault by measuring the resistance of the primary with set off as the current from the meter is usually enough to energize the speaker?
Rob

[Station X]

Originally Posted by Abraham

The resistor R15 measures 230 on the meter set at 2000k.

Is the reading of 230 followed by a "K" to indicate that the result is in Kilo ohms? Answer YES

Originally Posted by Abraham

How do I measure the +, ++, +++ that Graham mentions in post 55?

Look at the diagram attached to post #55

Meter on 1000V DC range. Negative lead to chassis.

+++ Postive lead to the positive terminal of C1. Should read 185V.
+ Positive lead to the positive terminal of C2. Should read 160V.
++ Positive lead to that side of R1 which DOES NOT go to C2. Should read 150V. Answer 126V

---------------------------------------------

TO TEST THE SPEAKER.

Disconnect one wire from it. Set you meter to the lowest ohms/resistance range. Touch the meter leads together and check that the reading is close to zero. Connect one lead to each speaker terminal. You should see a reading of about 5 ohms and may hear a click from the speaker as you connect the leads to it.

TO TEST THE OUTPUT TRANSFORMER SECONDARY WINDING.

This is what you appear to be measuing in post #63

One wire disconnected from the speaker. Connect one meter lead to this wire.
Connect the other meter lead to the speaker terminal which still has a wire attached. Note the reading.

[Abraham]

The reading of 230 was followed by a K

The R1 which does not go to C2 measured 126v

[Abraham]

On the output transformer secondary winding test, I disconnected one wire from the speaker and connected a meter lead to this wire and the other meter lead I connected it to the speaker terminal which still has the wire attached.
I got no reading on my multimeter.

[Station X]

I'm afraid that the secondary is open circuit then. Unless of course there's a break in one of the connecting wires? The difficulty in replacing it is that the primary winding also acts as a smoothing choke and the secondary has a tapped winding for the tone control.

Both problems can be overcome, but I'd try posting in sets and parts wanted first.

[Abraham]

Would this have anything to do with the problem?

[Station X]

The first picture shows the four tagged side of the transformer which is in fact the primary side. Despite the tag being ripped out it's still attached to the winding (I think) and should be OK. There should be a link between the two centre tags, but it looks like it may have been cut.

The secondary is the three tagged side. If there's no continuity between the three tags the transformer is open circuit.

Look at the service sheet top of chassis view and you'll see what I mean.

[Abraham]

On the two center tags of the for tagged side, the wire is not cut, I check it with continuity.
As far as the secondary thre tagged side, there is continuity on all three.

[Steve_P]

Is this with the speaker connected or not. A working speaker could conceal a faulty secondary, and a working secondary can hide a faulty speaker!

Cheers,

Steve P.

[Abraham]

On the four tagged side, is there supposed to be continuity on all four, because I have continuity on three, and the one that is ripped out, does not show any continuity.

[Steve_P]

Connect using the outer two of the three and remove any other links here.

Cheers,

Steve P.

[Station X]

Originally Posted by Abraham

As far as the secondary three tagged side, there is continuity on all three.

Originally Posted by Abraham

On the output transformer secondary winding test, I disconnected one wire from the speaker and connected a meter lead to this wire and the other meter lead I connected it to the speaker terminal which still has the wire attached.
I got no reading on my multimeter.

These statements can't both be true. Check the transformer again on the three tag side. If there's continuity between all three tags the secondary is OK. Please confirm this.

Connect your meter on ohms range across the two terminals of the speaker with at least one wire disconnected from the speaker. Do you get continuity? If so the speaker is OK.

On the primary (four tag side) of the transformer check for continuity to the tag which remains connected to the transformer, not the ripped out wire, and the other three tags.

EDIT. The tag which has pulled away has the anode of the UL84 and C30 connected to it. This must have been OK earlier or you'd have had no voltage on the anode of the UL84. I think a lot of your troubles could be down to disconnected wires to the transformer. Check them against the chassis drawing.

[Abraham]

I checked the three tag side, and there is continuity between all three tags.

[Station X]

What about the four tag side and the speaker?

[Abraham]

That's the part I did not understand well how I'm supposed to check.

I noticed on the chassis drawing of the transformer in the shcematics, that S19 and S20 are joined by the wire as well as tags 1,2, wire, 3,4. I don't know if I'm explaining myself well.