UK Vintage Radio Repair and Restoration Discussion Forum

UK Vintage Radio Repair and Restoration Discussion Forum (https://www.vintage-radio.net/forum/index.php)
-   Vintage Television and Video (https://www.vintage-radio.net/forum/forumdisplay.php?f=37)
-   -   Help with a Philips Anubis AAC Set (https://www.vintage-radio.net/forum/showthread.php?t=165423)

IKC2E51R8 5th Apr 2020 3:30 am

Help with a Philips Anubis AAC Set
 
1 Attachment(s)
Hi Everyone,

Now that ive got some free time i dug my old 21PT166A out of the attic to try get it working again, its been broken for a good while, we've had this set since new and its my childhood tv that i grew up watching so would love to get it going again.

So the problem with this originally was the flyback arced for about 10-15 seconds then boom, dead and mains fuse blew up (and kept blowing up when replaced).

Work done so far:

Looks like when the flyback arced and killed the set it took out the BUT11F with it so ive replaced both the Flyback (HR7772) and the BUT11F in the power supply. With the Flyback im a bit confused, the parts supplier I use came back with HR7772 as the replacment for my model but everywhere im seeing HR7488 as the replacment? (the pins are the same, everything else seems to be the same so im not sure if this could be causing the current problem)

Current Situation:

So the set now powers on and operates as normal (i assume) as there is no picture, no osd nothing on the screen yet HT and Deflection coils are operating, (sound is intermittant but thats because of the speaker cable got damaged) the CRT itself isnt heating or glowing orange as it normally would.

Ive replaced 3470, 6470 and 2470 in the 163v supply to the crt panel and no change, (i also dropped my meter today and damaged the screen -its all scrammbled so i cant measure voltages going to the base panel)

I'm just wondering has anyone seen a similar issue with an Anubis set and might have an idea what the story is with it, where i should be looking, Circuit diagram attached.

Appreciate any help recieved

1100 man 5th Apr 2020 10:32 am

Re: Help with a Philips Anubis AAC Set
 
Hi Luke,
Looking at the circuit diagram, the tube (CRT) heaters are fed from a winding on the line output transformer (Flyback transformer) as is usual practice. D94 & D96 on the diagram.

So if there is no orange glow from within the tube neck, the first question to ask is 'is the line output stage actually working'? The first thing I would do is measure the DC supplies that are produced by the LOPT. A bit difficult now you have dropped your meter!

If the 163V line is present across C2470, that would be a good indicator that there is life in the line stage.

I see the tube heaters have a fuse (1255 630ma) in parallel with a 1 ohm fusible resistor mounted on the tube base panel.

If the line stage is working and the above fuse is OK, check the tube heaters for continuity. It is possible that there is a difference in the pin connections on the flyback transformer and that the heater winding is not actually connected to where it should be!

Hope that helps

All the best
Nick

Red to black 5th Apr 2020 11:57 am

Re: Help with a Philips Anubis AAC Set
 
Quote:

Originally Posted by 1100 man (Post 1231667)
I see the tube heaters have a fuse (1255 630ma) in parallel with a 1 ohm fusible resistor mounted on the tube base panel.

If the line stage is working and the above fuse is OK, check the tube heaters for continuity. It is possible that there is a difference in the pin connections on the flyback transformer and that the heater winding is not actually connected to where it should be!

I might be mistaken here, and possibly confusing this with another Philips chassis, but I seem to think there might have been wire links that needed to be changed depending on which lopt was fitted, ie. the square based version or the round base.

Of course with a compatible type replacement I don't know for sure.
I would need to look more closely at the 'diversity tables' given in the full manual.
It is quite a while since I last looked at one of these sets.

Maarten 5th Apr 2020 3:55 pm

Re: Help with a Philips Anubis AAC Set
 
It's best to replace the flyback based on the number on the flyback itself, as some TV sets and chassis come in different versions.

Kyle__B 5th Apr 2020 5:49 pm

Re: Help with a Philips Anubis AAC Set
 
This might be a stupid question but have you turned the knobs on the new flyback? The power might just be set too low to do anything.

IKC2E51R8 5th Apr 2020 6:15 pm

Re: Help with a Philips Anubis AAC Set
 
Quote:

Originally Posted by Maarten (Post 1231767)
It's best to replace the flyback based on the number on the flyback itself, as some TV sets and chassis come in different versions.

Im kind of confused by these flyback, both different nu.bers HR7488 amd HR7772 but from the parts supplier both have the same number thats printed on the original flyback 1142.5001. They both look to be the exact same transformer and the parts supplier specifically mentions my exact model 21PT166A/07 where as for the HR7488 its not mentioned at all.

Why would they make two of the 'seemingly' exact same flyback but with different HR references

Quote:

Originally Posted by Kyle__B (Post 1231803)
This might be a stupid question but have you turned the knobs on the new flyback? The power might just be set too low to do anything.

That was my first thought but changing screen control on the FB did nothing

IKC2E51R8 5th Apr 2020 6:21 pm

Re: Help with a Philips Anubis AAC Set
 
Quote:

Originally Posted by 1100 man (Post 1231667)
Hi Luke,
Looking at the circuit diagram, the tube (CRT) heaters are fed from a winding on the line output transformer (Flyback transformer) as is usual practice. D94 & D96 on the diagram.

So if there is no orange glow from within the tube neck, the first question to ask is 'is the line output stage actually working'? The first thing I would do is measure the DC supplies that are produced by the LOPT. A bit difficult now you have dropped your meter!

If the 163V line is present across C2470, that would be a good indicator that there is life in the line stage.

I see the tube heaters have a fuse (1255 630ma) in parallel with a 1 ohm fusible resistor mounted on the tube base panel.

If the line stage is working and the above fuse is OK, check the tube heaters for continuity. It is possible that there is a difference in the pin connections on the flyback transformer and that the heater winding is not actually connected to where it should be!

Hope that helps

All the best
Nick

The fuse 1255 is not present on the board but the fuseable resistor is and is testing good, i replaced it anyway just in case and still nothing.

I have another multimeter somehwere in the house i just have to dig it out and hope it still works so i can measure those voltages.

Another thing i noticed was the line supply resistor 3444 is getting very hot after running for a minute or two (if that could help anyone with solving this)
I also let it run for about 5-10 minutes and it went into protective shut down but then started up just fine after unplugging and replugging. The HOT heat sink was very hot after it went into that shutdown

IKC2E51R8 5th Apr 2020 11:25 pm

Re: Help with a Philips Anubis AAC Set
 
I Found a multimeter and managed to see that on Pin 4 Connector L2 of the CRT Panel should be 163v and it measured at 192volts Pin 1 of this connector should be 163v also according to the schematic but its getting nothing 0v.

thats as far as i got measuring though as my ground probe for my multimeter broke (dont even know how, took a quick bathroom break and when i came back the probe was on the floor detached from the cable) Lesson learned, dont buy a 13 euro multimeter and expect it to last, New multimeter ordered for next day delivery (thank god for RS-Components)

anyways, with Pin for being 192v and pin 1 being 0v what do we reckon is going on?

also forgot to mention in the first post (may not be relevant) but when the BUT11 in the Power supply was cooked it took out two of the bridge rectifier diodes, i replaced all 4 of them anyway just in case.

ben 5th Apr 2020 11:43 pm

Re: Help with a Philips Anubis AAC Set
 
Odd that there's no CRT heaters if the fusible R is ok.
A few things spring to my mind:
- Mis connection from transformer pins to heater lines. Trace these out.
- Double check the heaters really aren't on, they can be hard to see. Turn off the lights and draw the curtains!
- Something else like the frame or RGB IC was shorted by the arcing and this is affecting/reducing the outputs on the line transformer secondary, possibly causing the overload you noted on that hot resistor. Isolate the loads.
- The arcing took out something else - jungle IC if you're unlucky?

Keep at it, you 'll get there!

1100 man 6th Apr 2020 12:10 am

Re: Help with a Philips Anubis AAC Set
 
Quote:

Originally Posted by IKC2E51R8 (Post 1231900)
I Found a multimeter and managed to see that on Pin 4 Connector L2 of the CRT Panel should be 163v and it measured at 192volts Pin 1 of this connector should be 163v also according to the schematic but its getting nothing 0v.

According to the circuit diagram, the 163V supply should be on PIN1 of L2. The heater supply goes to pin 3L2 & 4L2.

The heater supply is high frequency pulses, not smooth DC, so you won't get any meaningful results trying to measure it with a meter!

I'm still not convinced the line O/P stage is doing anything! The three main supply rails produced by the LOPT are the 163V on C2470. 13V on C2443. & 26V on C2453.

If you measure all three, that will indicate what's going on. Depending on the results, depends on where we go next!

Cheers
Nick

IKC2E51R8 6th Apr 2020 1:18 am

Re: Help with a Philips Anubis AAC Set
 
3 Attachment(s)
I'm confused because on both the Block diagram for the CRT Base and the PCB layout of the Base it shows Pin 4 is the supply and pins 1 & 3 are the heater pins, but on the schematic layout it has pin 1 as the supply?

Welsh Anorak 6th Apr 2020 12:07 pm

Re: Help with a Philips Anubis AAC Set
 
I'm with Nick on this - I suspect the stage isn't working, or at least with reduced efficiency. Don't worry about the heater voltage at the moment - it's the other LOPT-derived voltages that are key. What have you got? Also, the feed resistor shouldn't be overheating. If so, I suspect you've got a damaged line output BUT11/12 (not the PSU one - I know you've changed that) and the stage isn't working. So measure the HT voltage, then the LOPT derived voltages and let us know what they are.

IKC2E51R8 7th Apr 2020 2:06 pm

Re: Help with a Philips Anubis AAC Set
 
Quote:

Originally Posted by 1100 man (Post 1231904)
According to the circuit diagram, the 163V supply should be on PIN1 of L2. The heater supply goes to pin 3L2 & 4L2.

The heater supply is high frequency pulses, not smooth DC, so you won't get any meaningful results trying to measure it with a meter!

I'm still not convinced the line O/P stage is doing anything! The three main supply rails produced by the LOPT are the 163V on C2470. 13V on C2443. & 26V on C2453.

If you measure all three, that will indicate what's going on. Depending on the results, depends on where we go next!

Hi

New Multimeter arrived so i did those measurments:

163v is at 199v
26v = 27v
13v = 14v

1100 man 7th Apr 2020 8:52 pm

Re: Help with a Philips Anubis AAC Set
 
That's good. That means that the line O/P stage must be working. So the next thing to confirm is, are the tube heaters glowing? They would normally be quite easily visible when looking into the tube neck just forward of the tube base PCB assembly.

Cheers
Nick

IKC2E51R8 7th Apr 2020 8:57 pm

Re: Help with a Philips Anubis AAC Set
 
Tube heaters not glowing at all. Seems theres nothing getting to the the tube but there is supply to the crt board

IKC2E51R8 8th Apr 2020 2:19 am

Re: Help with a Philips Anubis AAC Set
 
A new problem has developed, i let it run for a few mins and it went dead, not totally dead but the loptx no longer starts and the Loptr is getting very hot after a minute or two, think i have it sussed to error sensing SM transistor 7537 a BC848C looks to be leaky its dragging the HT Down to 13v and from a quick online search seems to give a fair bit of trouble with Anubis sets, will have to wait till morning to replace it because il be kicked out if i go rummaging for a tweezers at this hour of the night. hate these tiny surface mount devices.

IKC2E51R8 8th Apr 2020 1:29 pm

Re: Help with a Philips Anubis AAC Set
 
Turns out that after replacing that trasistor the set was still dead, took a guess and figured the BUT11F in the Horizontal was cooked also, replaced it and set roared back to life, still no heaters though, no picture, i wont leave it run again as im afraid the BUT11 will be killed again.

Sideband 8th Apr 2020 8:13 pm

Re: Help with a Philips Anubis AAC Set
 
Watch what you use in the line stage. BUT11, BUT11F and BUT11AF....replace with the same type as fitted.

IKC2E51R8 8th Apr 2020 8:26 pm

Re: Help with a Philips Anubis AAC Set
 
11AF was fitted, Replaced with same. Any suggestions on how to get the pic back. Heaters still not running in it

ekjdm14 9th Apr 2020 12:21 pm

Re: Help with a Philips Anubis AAC Set
 
Hate to wonder this, but have you verified continuity in the CRT filaments?

If there's power getting to the board, can it be that hard to just "follow the money" on the foil side and see where you're losing it?


All times are GMT +1. The time now is 9:53 am.

Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.