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Old 26th Jun 2013, 8:58 pm   #1
beltinge bore
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Default Alba t655

This was found at Bvws Harpenden described as "untouched" this turned out to be true (well not for some time anyway)Evidence of previous work was no cover on LOPT new looking PCL82 & changed caps on frame board.

I wound it up on the variac and got severe mains hum.Looking at the main smoother cap it wasnt difficult to see why bulging & weeping from end cap.I cobbled up a replacement (Bush tv 22 60/250uf & 40 uf).This gave me valve & tube heaters but no HT.This was caused by 26ohm wirewound fromPY33 being O/C.

HT restored gave some sound noise but no line whistle or EHT the EY 86 heater was dead.I poked about a bit and got a faint line whistle with the contrast fully advanced.so I tried a NOS PY81 & PL81 .I now lost valve heaters.I was convinced I had done something daft so went over all my previous work to no avail.The new PL81 turned out to have a duff heater.I fitted another & got line whistle & a nice bright raster.I was a happy old man!

Applied the Aurora and found CH 3 gave me low sound & locked testcard.Not a bad afternoons work for a bumbling old fool I thought.
I have started replacing Waxys one at a time.Would I be right in thinking that what seem to be mullard mustard caps should br OK or should these be changed as well?
Thanks and Regards Steve.

Last edited by beltinge bore; 26th Jun 2013 at 9:00 pm. Reason: spelling
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Old 26th Jun 2013, 9:04 pm   #2
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Default Re: Alba t655

Mustard caps almost never fail, good work so far. Some pictures ?



Stephen
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Old 26th Jun 2013, 9:33 pm   #3
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Default Re: Alba t655

I have always found the mustard caps to be fine, I recently restored a Philips TG1700U, this had the earlier (green) caps, all were spot on, there were only 3 wax/tar caps in the set to replace.

What year is your Alba?

Mark
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Old 27th Jun 2013, 9:03 am   #4
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Default Re: Alba t655

Hello all.The ALBA was born in 1958 typical bent plywood cellulose finished cabinet the back cover is heat damaged & a previous repairer had fixed the IF panel with a wood screw & used a 2" wood screw as a top chassis mount which has pierced the tube mask.I was given one of these ALBAs by an aunt in about 1964 .It only needed a new EY 86.Happy days (BigL 266 on the wireless) and Anglia on CH11 in Muswell Hill North London.

Will soldier on with it thanks for replies Regards Steve.
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Old 27th Jun 2013, 10:33 am   #5
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Default Re: Alba t655

Remember to turn the gain controls to maximum for your tests. [No AGC] The Aurora will give a massive signal and when working correctly the T655 is quite a sensitive receiver. I think it was around 1966 when I last repaired one of these. John.
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Old 27th Jun 2013, 11:02 am   #6
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Default Re: Alba t655

The Alba T655 was the first set from the company to use the "packaged service" facility which dealers could offer their customers quick repairs to their sets. A faulty printed circuit board was simply posted to the Alba service department and and a replacement would be sent back on receipt of the board needing repair. Some dealers would have spare printed panels on the shelf.
The service was available on many later Alba made sets.
It should be borne in mind that many TV dealers did not not have very good service facilties and the packaged service would assist getting a fast turn around of repair work. Also most service engineers did not have an oscilloscope which today is considered a vital tool for TV servicing.
The Alba T655 has two PCB assemblies. A later model, the T656, employs an identical chassis except for cabinet styling differences.
The attachment shows the sound circuits of the T655. Note the high value resistors around the interference limiter stage. All should be checked.

DFWB.
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Old 29th Jun 2013, 8:31 pm   #7
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Default Re: Alba t655

Have changed all waxy caps (apart from a couple of hard to do small ones on the IF board.)I removed main chassis to access caps behind.I carefully (or so I thought) refitted the chassis with SHMBO help.On turn on the heaters came on OK but nothing else until a small amount of smoke issued,I quickly switched off.1 amp fuse had blown.I retraced all my steps .On replacing chassis I had managed to push two tags on a small tag strip behind the LOPT together.OOPS:-Turned back on everything seemed OK.I reset picture shift bits and bobs.Sound is better but still not 100%.Picture on testcard has very slight cogging.I left it overnight.

On trying today the sound motorboats and the picture changes size in sympathy.This lasts for about a minute then settles down OK.Would I be right in thinking that I have B-------,my nice new smoothers?Yours in desperation & Regards Steve.
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Old 29th Jun 2013, 8:51 pm   #8
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Default Re: Alba t655

Your smoothers will be fine. Check to make sure you have replaced the decoupling capacitors to pin 8 of the I.F. amplifiers. These will cause motor boating if O/C. They should be 1000pf [.001uf] ceramic types but slightly higher values up to 3000pf [.003uf]can be employed if you don't have the originals to hand.
If you have slight cogging, again make sure the sync coupling capacitor has been replaced C18 .1uf on the Newnes circuit.
Check the edge connector on the I.F. panel and make sure the earth track of the print is connected to chassis. They are normally very stable receivers. There should be loads of gain demanding a low setting of the Band 1 gain control. If the gain controls work in the wrong order Mr twiddler has put the biscuits in the tuner in the wrong positions. The wafer switch on the back does the gain pot switching so if someone has put the Band 3 coils in any Band 1 position the results will be obvious. Good luck with it. Regards, John.
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Old 29th Jun 2013, 9:00 pm   #9
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Default Re: Alba t655

With regard to sound problems. Check the electrolytic capacitors C30 and C33..
C33 is situated on the main chassis assembly.
Some useful information for the T655 can be found in the 1958/59 Red Radio & TV servicing book.
DFWB.
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Old 2nd Jul 2013, 10:15 am   #10
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Default Re: Alba t655

Changed C33 100uf on IF board.C30 was part of main smoother can which was the first component I changed.My 58/59 Newnes only has about half a page on the T655 in it.I have been using trader sheet but found a BRTA sheet that numbers the same as Newnes.Still have sound problem.A proper resistor check is my next job.(after pin 8 caps) .Replaced C18 which had already been changed in the past for a Mullard mustard still have slight cogging .

Cabinet has come up OK SHMBO is knocking me up a number ring for the turret knob .Onward & upward Regards Steve.
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Old 2nd Jul 2013, 7:20 pm   #11
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Default Re: Alba t655

Hi FERNSEH

I'm intrigued with the 'packaged service' for Alba. Did Philips offer that service for their sets do you know at any stage.

I'd like to add a piece on the website about it if anyone has any further info.

Many thanks

Robert


Quote:
Originally Posted by FERNSEH View Post
The Alba T655 was the first set from the company to use the "packaged service" facility which dealers could offer their customers quick repairs to their sets. A faulty printed circuit board was simply posted to the Alba service department and and a replacement would be sent back on receipt of the board needing repair. Some dealers would have spare printed panels on the shelf.
The service was available on many later Alba made sets.
It should be borne in mind that many TV dealers did not not have very good service facilties and the packaged service would assist getting a fast turn around of repair work. Also most service engineers did not have an oscilloscope which today is considered a vital tool for TV servicing.
The Alba T655 has two PCB assemblies. A later model, the T656, employs an identical chassis except for cabinet styling differences.
The attachment shows the sound circuits of the T655. Note the high value resistors around the interference limiter stage. All should be checked.

DFWB.

Last edited by Philips Fan; 2nd Jul 2013 at 7:27 pm.
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Old 2nd Jul 2013, 7:29 pm   #12
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Default Re: Alba t655

David might confirm this but ALBA were the only company that offered an exchange repair service on their plug in boards until the colour era. They were 35/- exchange in the mid 1960's but as a very young engineer, repaired them myself as did 90% of agents.
They must have been very handy with rental companies especially as living rooms tended to be much darker than they are today and repairs in the house could be an ordeal. Even then I expect most boards were serviced in a 'slave' chassis back at the service dept. Alba produced some great models but ran to seed around 1960-61 as many top makers did likewise. Regards, John.
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Old 2nd Jul 2013, 7:46 pm   #13
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Default Re: Alba t655

Thanks for that info John

As you know I'm always after info/stories about Philips sets and their derivatives.

The period of interest is 1965 to 1980 really.

Thanks

Robert
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Old 2nd Jul 2013, 9:44 pm   #14
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Default Re: Alba t655

Until Philips introduced their panel exchange service at their various depots around the Country I don't know of any other TV manufacture that offered an exchange service for PCB assemblies.
As John says very few engineers actually sent the panels off for exchange but it goes without saying having spare panels that simply plugged in was a great boon to any firm offering a TV rental service.
The Alba T655 was popular with TV rental firms.
Again, as John states Alba kinda lost it in terms of ease of service when they got clever with their own dual standard TVs. They threw in the towel and bought in dual standard TV sets from other manufactures. Nevertheless, Alba was still an independent concern in 1962 and was right through to the mid seventies.

DFWB.
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Old 3rd Jul 2013, 5:46 am   #15
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Default Re: Alba t655

Thanks for this info chaps.
Regards
Robert
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Old 5th Jul 2013, 1:29 pm   #16
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Default Re: Alba t655

Hello I have Changed a couple of resistors in sound area which had gone a bit high slightly improved sound .I got brave and changed the 2 remaining tiny waxys on the IF board.I now have quite good sound apart from hum which varies with operation of the volume control it almost dissappears mid position.
Replaced a couple of small Ekco type caps as John suggested to pin 8 of the sound EF80s as usual he was right motor boating now cured.
I found the very flimsy earth lead from the tuner chassis to the volume pot had broken away.This cured my switch on problems but not the hum on sound.
I still have very slight cogging.I noticed in my scribbled notes that the cap on the wafer switch to gain controls 0.02uf Should be 1000v .I have used 630v. Would it be worthwhile trying a 1kv in its place?I assumed 630v cap would be OK in a relatively "unstressed" situation.Still learning .
I never thought any hobby could beat restoring old vehicles but this is addictive

Thanks & Regards Steve..
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Old 5th Jul 2013, 2:49 pm   #17
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Default Re: Alba t655

With regard to the hum which varies when the volume control is turned. It does seem a bit strange that hum dissappears when the control is at the centre position. You could try this if it has not been done already replacing the lead from the slider of the control with a piece of screened lead.
Also make sure that the earthy end of the volume control is not connected to mains neutral. You can experience all sorts of funny effects when this done.

DFWB.

Last edited by FERNSEH; 5th Jul 2013 at 3:05 pm.
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Old 5th Jul 2013, 3:25 pm   #18
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Default Re: Alba t655

Just a thought. Has the volume control been replaced? The metal case needs bonding to chassis usually via the screened cable. Worth a check. A sloppy guy may have omitted this when replacing. John.
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Old 5th Jul 2013, 4:15 pm   #19
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Default Re: Alba t655

Quote:
Originally Posted by Heatercathodeshort View Post
A sloppy guy may have omitted this when replacing. John.
That's right. There's a chance that the set was subject to some of the terrible service work carried out in the sixties.

DFWB.
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Old 6th Jul 2013, 9:40 am   #20
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Default Re: Alba t655

Hello.Thanks for your help as always.Did a bit of "lead dressing" and resoldered braiding to volume pot.Sound is now about as good as I can get it.
I thought I would give it a short soak test before re-boxing.On switch on the frame takes a minute to settle(thermister on vision panel I presume).It sits nicely frame & width wise for about 20 minutes (brightness increases slightly) then the Height increases quickly (from the top of the picture) and the width come in about an inch either side.Advancing brightness or contrast causes picture to "balloon" and disappear .
Tried a new EY86 with no change.LOPT is not hot to touch.
On the frame board there are 2 caps C37/C41 which are half blue half white plastic construction which I have left unchanged.These look to be replacements from previous work .Should these be changed?.HT sits at 183 through all this.
Hope i havent wasted my and your time on this.I have grown quite fond of it (even some of its bodges!).
Thanks & Regards Steve.
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