Official 33609 builder's tread. See 1st page for updates.

[Igor]

If there's 4-10 v on r44, something draws a lot of current. Just check everything.

 

[Vito Janeiro]

And the trimpot on ba340 seems to operate the opposite way, when turned to minimum, CCV the voltage on r44 is higher...

 

[Igor]

Remove BA340 and check if anything else draws too much current.
Or, try to adjust trimpot on BA340 to max (CCV) position, maybe here is the prob.

 

[rrs]

so on R44 we are measuring between each side of the resistor to get approximatly 280MV. I am getting 153MV but not adjusting when I adjust trimpot on BA340. Trimpot is working and have adjusted fully.
I am measuring 16V from R44 to ground.

Problem is same with both boards. I am a little lost here so some help would be good.

 

[Igor]

hm...wait. Just check BA340 and all components across.

 

[rrs]

hm...wait. Just check BA340 and all components across.

All componants appear to be correct transistors, capacitors diodes correct orientation. No bridges am measuring 12V at TP_D (24.3V from PSU).
C16,17,18 are 470uf. C23 is 1.5nf.

Any suggestions on further tests to weed out the problem. As it's happening on both boards I assume I have done something wrong.

 

[Rob Flinn]

Are any of the power transistors bodies on the BA340 touching, the bodies are are electrically attached to 1 leg of the transistor & are quite close together !

Are you definitely using the EBC versions of the bc214 ??

 

[Vito Janeiro]

Hello Guys

In post#16 Igor says that we should use cbe versions.

Its quite clear what is the proper pin layout in BA340 and also in the main board, I am having the same problem with r44 burning...

I´we replaced every bc214 and bc 184 with similar as a test, (bc560 and bc 183) without success. Both boards acting the same way on first power up...

I´m planning to replace every part except the resistors on ba340 to make sure everything is correct. If some of you have the order codes for ba340 from mouser etc I´d give you a BIG THANX, I´m getting tired

I think I recall some discussiong about some heatsink in ba340, but you who have finnished the unit didn´t use them. I´m just curious about the heat issues, and I´d also like to have your opinion about connecting the ba340 to main board, why could´n it be done with wires...

Cheers in advance,

Vito

 

[Igor]

CBE pinout printed on every transistor on PCB, except BC441.
Check BA340 point by point, maybe there's wrong resistor, reversed polarity diode,
or BC441 swaped with BC461. Check every transistor with multimeter on "diode" range.
This way you can know btw if the transistor's pinout correct (ebc or bce).
There's parts for using JE990 type opamp, with suffix "J". They printed on back side of PCB
and not installed with BA340.

Transistors from Farnell (sorry, Mouser is problem in Israel
http://il.farnell.com/fairchild-semiconductor/bc184c/transistor-npn-to-92/dp/1017657
http://il.farnell.com/fairchild-semiconductor/bc214/transistor-pnp-to-92/dp/1017665&crosssellid=1017665&crosssell=true&in_merch=true&
http://il.farnell.com/magnatec/bc441/transistor-npn-to-39/dp/1208596&crosssellid=1208596&crosssell=true&in_merch=true&
http://il.farnell.com/magnatec/bc461/transistor-pnp-to-39/dp/1208598
http://il.farnell.com/on-semiconductor/mje371g/transistor-pnp-to-225/dp/1459092
BA340 works fine on quescient current 6-15 mA without heatsinks.
Connecting BA340 with wires... Dunno. I suppose it will not oscillate with 50-60 mm wires, but why not
take the standard pins from IC socket and solder it to PCB.... Take IC socket and cutter, cut plastic...done.

 

[Rob Flinn]

In post#16 Igor says that we should use cbe versions.

Vito

You're right of course.  I just knew they had to be the right ones.

I built up a small test jig on strip board, with some pcb sockets to test the BA340 out of the main board.  This is useful since you don't keep frying the same resistor on the main board, which you then have to keep replacing & wind up damaging the tracks on the board.  Might be useful.

 

[Vito Janeiro]

Igor, what is this MJE371G in your list? Is it replacing something?

Vito

 

[Rob Flinn]

It is an MJE371 on the original Neve diagram

 

[Vito Janeiro]

But it´s not located on ba340?

Vito

 

[Igor]

Nope. MJE371 located on motherboard.
These are  links to transistors used in 2254C available from Farnell.

 

[Vito Janeiro]

Thanks guys!

Some improvement, R44 is ok and the voltage also.

CV+ is 3V, connected to link in main PCB

Relays are not working, so my unit is bypassed all the time. 12V link connected, and I get 24V when bypass is switched, but relays don´t click. Rhey work properly with external 12V...

Few questions, where is the link1 from bypass pcb going to be connected?

In main pcm com att1 and com att2?

Sorry guys, but Im stupid...

V

 

[Rob Flinn]

Can you check that you have 24v going to the bypass switch ?  I think this might be something you have to hook up which isn't on a ribbon connector

 

[Vito Janeiro]

Yes, 24v is connected from the psu board...

 

[Rob Flinn]

Yes, 24v is connected from the psu board...

Check that it is getting to the relyas when you flick the switch.

Check that you also have the back emf diodes across the relays the right way round.

Make sure that if your running 12v relays that the 2 pads marked 12v near the relays are bridged.    If you are running 24v relays check that you have the 2 sets of pads marked 24v near the relays bridged.     If you have these bridged make sure you check the continuity with a meter.


Also if you remove the by_link-meter header you could try connecting your external power source to pins 1 & 2 of the header on the main pcb, which you can see run round to the relays & see if they click over.  I think pin1 should be positive.  If this works then you have a problem somewhere round the switch.

You could also connect your meter to the cable coming from the switch pcb to see if you have 24 there when you flick the bypass switch.

Really you should try to think about this logically, if you have a meter you should be able to work out where the power stops.

 

[Vito Janeiro]

Thanks Rob!

I just needed to know if the trim on main board needs to be connected before chasing the fault. I got it now, thanks for the support Relays working now...

Vito

 

[rrs]

Like a few people here I have a Sifam AL19W but the VU type sold at canford. I am wondering id the SSLTech GSSL VU mod here
http://www.expataudio.com/expatshop/index.php?act=viewProd&productId=7
will enable my meter to work with this project